AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPsychiatry and PsychologyPhenomena and ProcessesDisciplines and Occupations
Chemoreceptor CellsCarotid BodyAortic BodiesAlmitrineAnoxiaCatecholaminesOxygenKv1.4 Potassium ChannelShal Potassium ChannelsPotassium Channels, Tandem Pore DomainRabbitsPotassiumSodium CyanideTetraethylammoniumDinitrophenolsThioureaPotassium ChannelsLarge-Conductance Calcium-Activated Potassium ChannelsMembrane PotentialsRespirationCarotid SinusCarbon DioxideCell HypoxiaParaganglia, NonchromaffinPotassium Channels, Voltage-GatedNifedipineChemotaxisElectrophysiologyCalciumPatch-Clamp TechniquesHypercapniaRats, WistarPressoreceptorsReflexGlossopharyngeal NerveVagotomyDenervationCatsCells, CulturedPhrenic NerveMedulla OblongataImmunohistochemistryRespiratory CenterAsphyxiaApneaNeurons, EfferentRespiratory MechanicsPulmonary VentilationCyanidesBacterial ProteinsSolitary NucleusVagus NerveReceptors, Amino AcidHyperoxia
Chemoreceptor Cells
Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.
Carotid Body
A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.
Aortic Bodies
Small clusters of chemoreceptive and supporting cells located near the ARCH OF THE AORTA; the PULMONARY ARTERIES; and the CORONARY ARTERIES. The aortic bodies sense PH; CARBON DIOXIDE; and OXYGEN concentrations in the BLOOD and participate in the control of RESPIRATION. The aortic bodies should not be confused with the PARA-AORTIC BODIES in the abdomen (which are sometimes also called aortic bodies).
Almitrine
A respiratory stimulant that enhances respiration by acting as an agonist of peripheral chemoreceptors located on the carotid bodies. The drug increases arterial oxygen tension while decreasing arterial carbon dioxide tension in patients with chronic obstructive pulmonary disease. It may also prove useful in the treatment of nocturnal oxygen desaturation without impairing the quality of sleep.
Anoxia
Relatively complete absence of oxygen in one or more tissues.
Catecholamines
A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.
Oxygen
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
Kv1.4 Potassium Channel
A fast inactivating subtype of shaker potassium channels that contains two inactivation domains at its N terminus.
Shal Potassium Channels
A shaker subfamily of potassium channels that participate in transient outward potassium currents by activating at subthreshold MEMBRANE POTENTIALS, inactivating rapidly, and recovering from inactivation quickly.
Potassium Channels, Tandem Pore Domain
Potassium channels that contain two pores in tandem. They are responsible for baseline or leak currents and may be the most numerous of all K channels.
Rabbits
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Potassium
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
Sodium Cyanide
A highly poisonous compound that is an inhibitor of many metabolic processes and is used as a test reagent for the function of chemoreceptors. It is also used in many industrial processes.
Tetraethylammonium
A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)
Dinitrophenols
Organic compounds that contain two nitro groups attached to a phenol.
Thiourea
A photographic fixative used also in the manufacture of resins. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), this substance may reasonably be anticipated to be a carcinogen (Merck Index, 9th ed). Many of its derivatives are ANTITHYROID AGENTS and/or FREE RADICAL SCAVENGERS.
Potassium Channels
Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.
Large-Conductance Calcium-Activated Potassium Channels
A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical signaling in a variety of tissues.
Membrane Potentials
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Respiration
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
Carotid Sinus
The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.
Carbon Dioxide
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Cell Hypoxia
A condition of decreased oxygen content at the cellular level.
Paraganglia, Nonchromaffin
Several clusters of chemoreceptive and supporting cells associated with blood vessels and nerves (especially the glossopharyngeal and vagus). The nonchromaffin paraganglia sense pH, carbon dioxide, and oxygen concentrations in the blood and participate in respiratory, and perhaps circulatory, control. They include the CAROTID BODY; AORTIC BODIES; the GLOMUS JUGULARE; and the GLOMUS TYMPANICUM.
Potassium Channels, Voltage-Gated
Potassium channel whose permeability to ions is extremely sensitive to the transmembrane potential difference. The opening of these channels is induced by the membrane depolarization of the ACTION POTENTIAL.
Nifedipine
A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.
Chemotaxis
The movement of cells or organisms toward or away from a substance in response to its concentration gradient.
Electrophysiology
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
Calcium
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Patch-Clamp Techniques
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
Hypercapnia
A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.
Rats, Wistar
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Pressoreceptors
Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.
Reflex
An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
Glossopharyngeal Nerve
The 9th cranial nerve. The glossopharyngeal nerve is a mixed motor and sensory nerve; it conveys somatic and autonomic efferents as well as general, special, and visceral afferents. Among the connections are motor fibers to the stylopharyngeus muscle, parasympathetic fibers to the parotid glands, general and taste afferents from the posterior third of the tongue, the nasopharynx, and the palate, and afferents from baroreceptors and CHEMORECEPTOR CELLS of the carotid sinus.
Vagotomy
The interruption or removal of any part of the vagus (10th cranial) nerve. Vagotomy may be performed for research or for therapeutic purposes.
Denervation
The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)
Cats
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
Cells, Cultured
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Phrenic Nerve
The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.
Medulla Oblongata
The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.
Immunohistochemistry
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Respiratory Center
Part of the brain located in the MEDULLA OBLONGATA and PONS. It receives neural, chemical and hormonal signals, and controls the rate and depth of respiratory movements of the DIAPHRAGM and other respiratory muscles.
Asphyxia
A pathological condition caused by lack of oxygen, manifested in impending or actual cessation of life.
Apnea
A transient absence of spontaneous respiration.
Neurons, Efferent
Neurons which send impulses peripherally to activate muscles or secretory cells.
Respiratory Mechanics
The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.
Pulmonary Ventilation
The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.
Cyanides
Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.
Bacterial Proteins
Proteins found in any species of bacterium.
Solitary Nucleus
GRAY MATTER located in the dorsomedial part of the MEDULLA OBLONGATA associated with the solitary tract. The solitary nucleus receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves. It is a major coordinator of AUTONOMIC NERVOUS SYSTEM regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of HOMEOSTASIS. The solitary nucleus is also notable for the large number of NEUROTRANSMITTERS which are found therein.
Vagus Nerve
The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).
Receptors, Amino Acid
Cell surface proteins that bind amino acids and trigger changes which influence the behavior of cells. Glutamate receptors are the most common receptors for fast excitatory synaptic transmission in the vertebrate central nervous system, and GAMMA-AMINOBUTYRIC ACID and glycine receptors are the most common receptors for fast inhibition.
Hyperoxia
An abnormal increase in the amount of oxygen in the tissues and organs.

Post-ingestive feedbacks and associative learning regulate the intake of unsuitable sterols in a generalist grasshopper. (1/1554)

Behavioural studies of the grasshopper Schistocerca americana were undertaken to identify the mechanisms that regulate the intake of dietary sterols. In the first experiment, grasshoppers were allowed to feed on spinach, a plant containing only unsuitable sterols; immediately after this first meal, a suitable or unsuitable sterol was injected into the haemolymph. Grasshoppers injected with unsuitable sterols had second meals on spinach that were significantly shorter than those of grasshoppers injected with suitable sterols, indicating that unsuitable dietary sterols are detected post-ingestively. In the second experiment, grasshoppers were fed food containing only unsuitable sterols and were then presented with glass-fibre discs containing different concentrations of a suitable sterol or sucrose only (the control). The results suggest that grasshoppers do not use a direct feedback operating on mouthpart chemoreceptors to regulate their intake of suitable sterols. In the third experiment, grasshoppers were presented with artificial diets containing different sterols and flavours, and feeding was observed over a sequence of meals. The results from both the first and last experiments suggest a role for associative learning in regulating the intake of unsuitable sterols.  (+info)

Quantitative structure-activity relationships for nasal pungency thresholds of volatile organic compounds. (2/1554)

A model was developed for describing the triggering of nasal pungency in humans, based on the partition of volatile organic compounds (VOCs) between the air phase and the biophase. Two partition parameters are used in the model: the water-air partition coefficient and the octanol-water partition coefficient. The model was validated using data from the literature, principally on alcohols, acetates and ketones. The model suggests that all test compounds, regardless of their chemical functional groups, bind to a common receptor site within the hydrophobic interior of the bilayer membrane of the trigeminal nerve endings. There is probably only a slight, non-specific interaction between the VOC molecule and the receptor molecule, whereas this type of non-specific interaction for the detection of odor is much stronger. In practical terms, the suggestion that all VOCs share a common irritation receptor site implies that nasal-pungency thresholds of individual VOCs may be additive. Quantitative structure-activity relationships (QSARs) for nasal-pungency thresholds were also developed from the model, which can be used to predict nasal-pungency thresholds of common VOCs. Although the present model does not offer additional precision over that of M.H. Abraham et al., 1996, Fundam. Appl. Toxicol. 31, 71-76, it requires fewer descriptors and offers a physiological basis to the QSAR. Another advantage of the present model is that it also provides a basis for comparison between the olfactory process and nasal pungency.  (+info)

Chemotactic responses of Escherichia coli to small jumps of photoreleased L-aspartate. (3/1554)

Computer-assisted motion analysis coupled to flash photolysis of caged chemoeffectors provides a means for time-resolved analysis of bacterial chemotaxis. Escherichia coli taxis toward the amino acid attractant L-aspartate is mediated by the Tar receptor. The physiology of this response, as well as Tar structure and biochemistry, has been studied extensively. The beta-2, 6-dinitrobenzyl ester of L-aspartic acid and the 1-(2-nitrophenyl)ethyl ether of 8-hydroxypyrene-1,3,6-tris-sulfonic acid were synthesized. These compounds liberated L-aspartate and the fluorophore 8-hydroxypyrene 1,3,6-tris-sulfonic acid (pyranine) upon irradiation with near-UV light. Photorelease of the fluorophore was used to define the amplitude and temporal stability of the aspartate jumps employed in chemotaxis experiments. The dependence of chemotactic adaptation times on aspartate concentration, determined in mixing experiments, was best fit by two Tar aspartate-binding sites. Signal processing (excitation) times, amplitudes, and adaptive recovery of responses elicited by aspartate jumps producing less than 20% change in receptor occupancy were characterized in photorelease assays. Aspartate concentration jumps in the nanomolar range elicited measurable responses. The response threshold and sensitivity of swimming bacteria matched those of bacteria tethered to glass by a single flagellum. Stimuli of similar magnitude, delivered either by rapid mixing or photorelease, evoked responses of similar strength, as assessed by recovery time measurements. These times remained proportional to change in receptor occupancy close to threshold, irrespective of prior occupancy. Motor excitation responses decayed exponentially with time. Rates of excitation responses near threshold ranged from 2 to 7 s-1. These values are consistent with control of excitation signaling by decay of phosphorylated pools of the response regulator protein, CheY. Excitation response rates increased slightly with stimulus size up to values limited by the instrumentation; the most rapid was measured to be 16 +/- 3 (SE) s-1. This increase may reflect simultaneous activation of CheY dephosphorylation, together with inhibition of its phosphorylation.  (+info)

Trigeminal and carotid body inputs controlling vascular resistance in muscle during post-contraction hyperaemia in cats. (4/1554)

1. In anaesthetized cats, the effects of stimulation of the receptors in the nasal mucosa and carotid body chemoreceptors on vascular resistance in hindlimb skeletal muscle were studied to see whether the responses were the same in active as in resting muscle. The measurements of vascular resistance were taken, first, in resting muscle, and second, in the immediate post-contraction hyperaemic phase that followed a 30 s period of isometric contractions. 2. Stimulation of the receptors in the nasal mucosa caused reflex apnoea and vasoconstriction in muscle. The latter response was attenuated when the test was repeated during post-contraction hyperaemia. 3. Stimulations of the carotid bodies were made during a period of apnoea evoked reflexly by electrical stimulation of both superior laryngeal nerves. This apnoea prevented any effects of changes in respiration on the carotid body reflex vascular responses. Stimulation of the carotid bodies evoked hindlimb muscle vasoconstriction. In the post-contraction hyperaemic period, the response was reduced or abolished. A similar attenuation of the reflex vasoconstrictor responses occurred in decentralized muscles stimulated through their motor roots in the cauda equina. 4. Evidence is presented that the attenuation of the vasoconstrictor responses evoked by the two reflexes is a phenomenon localized to the contracting muscles themselves resulting from an interaction between sympathetic neuronal activity and the local production of metabolites. 5. The results are discussed in relation to the metabolic needs of tissues in relation to asphyxial defence mechanisms such as occur in the diving response.  (+info)

Depression of peripheral chemosensitivity by a dopaminergic mechanism in patients with obstructive sleep apnoea syndrome. (5/1554)

In the present study, respiratory drives to chemical stimuli and peripheral chemosensitivity were evaluated in patients with obstructive sleep apnoea (OSAS). The effects of oral administration of domperidone, a selective dopamine D2-receptor antagonist, were also examined, to study the respiratory effects of endogenous dopamine on peripheral chemoreceptors. Sixteen patients with OSAS and nine normal control subjects were studied. Respiratory responses to hypercapnia and hypoxia were measured using the rebreathing method and isocapnic progressive hypoxia method, respectively. The hypoxic withdrawal test, which measures the decrease in ventilation caused by two breaths of 100% O2 under mild hypercapnic hypoxic conditions (end-tidal oxygen and carbon dioxide tensions approximately 8.0 kPa and 5.3-6.7 kPa, respectively), was used to evaluate peripheral chemosensitivity. In the patients with OSAS, ventilatory responses to hypercapnia and hypoxia were significantly decreased compared with those of control subjects. Hypoxic withdrawal tests showed that peripheral chemosensitivity was significantly lower in patients with OSAS than in normal subjects. Hypercapnic ventilatory response and peripheral chemosensitivity were enhanced by administration of domperidone in the patients with OSAS, although no changes in either of these were observed in the control subjects. The hypoxic ventilatory response and peripheral chemosensitivity in the patients with OSAS were each significantly correlated with severity of hypoxia during sleep. These findings suggest that peripheral chemosensitivity in patients with obstructive sleep apnoea syndrome may be decreased as a result of abnormality in dopaminergic mechanisms and that the reduced chemosensitivity observed in patients with obstructive sleep apnoea syndrome may affect the severity of hypoxia during sleep.  (+info)

BDNF is a target-derived survival factor for arterial baroreceptor and chemoafferent primary sensory neurons. (6/1554)

Brain-derived neurotrophic factor (BDNF) supports survival of 50% of visceral afferent neurons in the nodose/petrosal sensory ganglion complex (NPG; Ernfors et al., 1994a; Jones et al., 1994; Conover et al., 1995; Liu et al., 1995; Erickson et al., 1996), including arterial chemoafferents that innervate the carotid body and are required for development of normal breathing (Erickson et al., 1996). However, the relationship between BDNF dependence of visceral afferents and the location and timing of BDNF expression in visceral tissues is unknown. The present study demonstrates that BDNF mRNA and protein are transiently expressed in NPG targets in the fetal cardiac outflow tract, including baroreceptor regions in the aortic arch, carotid sinus, and right subclavian artery, as well as in the carotid body. The period of BDNF expression corresponds to the onset of sensory innervation and to the time at which fetal NPG neurons are BDNF-dependent in vitro. Moreover, baroreceptor innervation is absent in newborn mice lacking BDNF. In addition to vascular targets, vascular afferents themselves express high levels of BDNF, both during and after the time they are BDNF-dependent. However, endogenous BDNF supports survival of fetal NPG neurons in vitro only under depolarizing conditions. Together, these data indicate two roles for BDNF during vascular afferent pathway development; initially, as a target-derived survival factor, and subsequently, as a signaling molecule produced by the afferents themselves. Furthermore, the fact that BDNF is required for survival of functionally distinct populations of vascular afferents demonstrates that trophic requirements of NPG neurons are not modality-specific but may instead be associated with innervation of particular organ systems.  (+info)

Selective potentiation of peripheral chemoreflex sensitivity in obstructive sleep apnea. (7/1554)

BACKGROUND: The chemoreflexes are an important mechanism for regulation of both breathing and autonomic cardiovascular function. Abnormalities in chemoreflex mechanisms may be implicated in increased cardiovascular stress in patients with obstructive sleep apnea (OSA). We tested the hypothesis that chemoreflex function is altered in patients with OSA. METHODS AND RESULTS: We compared ventilatory, sympathetic, heart rate, and blood pressure responses to hypoxia, hypercapnia, and the cold pressor test in 16 untreated normotensive patients with OSA and 12 normal control subjects matched for age and body mass index. Baseline muscle sympathetic nerve activity (MSNA) was higher in the patients with OSA than in the control subjects (43+/-4 versus 21+/-3 bursts per minute; P<0. 001). During hypoxia, patients with OSA had greater increases in minute ventilation (5.8+/-0.8 versus 3.2+/-0.7 L/min; P=0.02), heart rate (10+/-1 versus 7+/-1 bpm; P=0.03), and mean arterial pressure (7+/-2 versus 0+/-2 mm Hg; P=0.001) than control subjects. Despite higher ventilation and blood pressure (both of which inhibit sympathetic activity) in OSA patients, the MSNA increase during hypoxia was similar in OSA patients and control subjects. When the sympathetic-inhibitory influence of breathing was eliminated by apnea during hypoxia, the increase in MSNA in OSA patients (106+/-20%) was greater than in control subjects (52+/-23%; P=0.04). Prolongation of R-R interval with apnea during hypoxia was also greater in OSA patients (24+/-6%) than in control subjects (7+/-5%) (P=0.04). Autonomic, ventilatory, and blood pressure responses to hypercapnia and the cold pressor test in OSA patients were not different from those observed in control subjects. CONCLUSIONS: OSA is associated with a selective potentiation of autonomic, hemodynamic, and ventilatory responses to peripheral chemoreceptor activation by hypoxia.  (+info)

NADPH oxidase inhibition does not interfere with low PO2 transduction in rat and rabbit CB chemoreceptor cells. (8/1554)

The aim of the present work was to elucidate the role of NADPH oxidase in hypoxia sensing and transduction in the carotid body (CB) chemoreceptor cells. We have studied the effects of several inhibitors of NADPH oxidase on the normoxic and hypoxia-induced release of [3H]catecholamines (CA) in an in vitro preparation of intact CB of the rat and rabbit whose CA deposits have been labeled by prior incubation with the natural precursor [3H]tyrosine. It was found that diphenyleneiodonium (DPI; 0.2-25 microM), an inhibitor of NADPH oxidase, caused a dose-dependent release of [3H]CA from normoxic CB chemoreceptor cells. Contrary to hypoxia, DPI-evoked release was only partially Ca2+ dependent. Concentrations of DPI reported to produce full inhibition of NADPH oxidase in the rat CB did not prevent the hypoxic release response in the rat and rabbit CB chemoreceptor cells, as stimulation with hypoxia in the presence of DPI elicited a response equaling the sum of that produced by DPI and hypoxia applied separately. Neopterin (3-300 microM) and phenylarsine oxide (0.5-2 microM), other inhibitors of NADPH oxidase, did not promote release of [3H]CA in normoxic conditions or affect the response elicited by hypoxia. On the basis of effects of neopterin and phenylarsine oxide, it is concluded that NADPH oxidase does not appear to play a role in oxygen sensing or transduction in the rat and rabbit CB chemoreceptor cells in vitro and, in the context of the present study, that DPI effects are not related to NADPH oxidase inhibition.  (+info)

Peripheral chemoreceptor inputs to medullary inspiratory and postinspiratory neurons of cats<...
TY - JOUR. T1 - Peripheral chemoreceptor inputs to medullary inspiratory and postinspiratory neurons of cats. AU - Lawson, Edward E.. AU - Richter, Diethelm W.. AU - Ballantyne, David. AU - Lalley, Peter M.. AU - Bischoff, Annemarie. AU - Kühner, Anita. PY - 1989/9/1. Y1 - 1989/9/1. N2 - The effect of peripheral chemoreceptor activation on inspiratory and postinspiratory medullary neurons was investigated using intracellular recording techniques. Peripheral chemoreceptors were activated by injecting CO2 saturated 1 N bicarbonate solution into the lingual artery or by electrically stimulating the carotid sinus nerve. Injections of 20-300 μl bicarbonate solution evoked changes in respiratory frequency and in peak phrenic nerve discharge. The membrane potential of inspiratory alpha neurons, whether bulbospinal or not and independent of their anatomic location, was decreased during inspiration. A sequence of compound excitatory and inhibitory effects were observed when the stimulus was given ...
https://jhu.pure.elsevier.com/en/publications/peripheral-chemoreceptor-inputs-to-medullary-inspiratory-and-post-3
Effect of stimulation of carotid chemoreceptors on total and regional cerebral blood flow. | Circulation ResearchEffect of stimulation of carotid chemoreceptors on total and regional cerebral blood flow. | Circulation Research
This study was performed to determine whether stimulation of the carotid chemoreceptors increases total or regional cerebral blood flow and whether activation of arterial chemoreceptors contributes to cerebral vasodilation during systemic hypoxemia. In anesthetized and ventilated dogs, carotid chemoreceptors were stimulated with nicotine or hypoxic and hypercapnic blood. To measure total and regional cerebral blood flow, we used labeled 15-mu microspheres. Stimulation of chemoreceptors did not increase cerebral blood flow or produce significant redistribution of cerebral blood flow, even though the chemoreflex was intact in these animals (as manifested by vasoconstriction in muscle, kidney, and small bowel) and the cerebral vessels dilated in response to systemic hypercapnia. In other studies in anesthetized, ventilated dogs and rhesus monkeys, cerebral vasodilator responses to systemic hypoxemia were observed before and after denervation of carotid and aortic chemoreceptors. Systemic hypoxemia ...
http://circres.ahajournals.org/content/38/1/20
Cellular mechanisms involved in CO<sub>2</sub> and acid signaling in chemosensitive...
TY - JOUR. T1 - Cellular mechanisms involved in CO2 and acid signaling in chemosensitive neurons. AU - Putnam, Robert W.. AU - Filosa, Jessica A.. AU - Ritucci, Nicola A.. PY - 2004/12. Y1 - 2004/12. N2 - An increase in CO2/H+ is a major stimulus for increased ventilation and is sensed by specialized brain stem neurons called central chemosensitive neurons. These neurons appear to be spread among numerous brain stem regions, and neurons from different regions have different levels of chemosensitivity. Early studies implicated changes of pH as playing a role in chemosensitive signaling, most likely by inhibiting a K+ channel, depolarizing chemosensitive neurons, and thereby increasing their firing rate. Considerable progress has been made over the past decade in understanding the cellular mechanisms of chemosensitive signaling using reduced preparations. Recent evidence has pointed to an important role of changes of intracellular pH in the response of central chemosensitive neurons to increased ...
https://augusta.pure.elsevier.com/en/publications/cellular-mechanisms-involved-in-cosub2sub-and-acid-signaling-in-c
Cheap Nike Jordans Shoes - Assigning chemoreceptors to chemosensory pathways in Pseudomonas aeruginosaCheap Nike Jordans Shoes - Assigning chemoreceptors to chemosensory pathways in Pseudomonas aeruginosa
In contrast to Escherichia coli, a model organism for chemotaxis that has 5 chemoreceptors and a single chemosensory pathway, Pseudomonas aeruginosa PAO1 has a much more complex chemosensory network, which consists of 26 chemoreceptors feeding into four chemosensory pathways. While several chemoreceptors were rigorously linked to specific pathways in a series of experimental studies, for most of them this information is not available. Thus, we addressed the problem computationally. Protein-protein interaction network prediction, coexpression data mining, and phylogenetic profiling all produced incomplete and uncertain assignments of chemoreceptors to pathways. However, comparative sequence analysis specifically targeting chemoreceptor regions involved in pathway interactions revealed conserved sequence patterns that enabled us to unambiguously link all 26 chemoreceptors to four pathways. Placing computational evidence in the context of experimental data allowed us to conclude that three ...
http://www.danielhellerman.com/content/114/48/12809.abstract?sid=9360f931-b062-46b8-934b-ca86d32af674
Mitochondrial Complex I Dysfunction and Peripheral Chemoreflex Sensitivity in a FASTK-Deficient Mice Model - PubMedMitochondrial Complex I Dysfunction and Peripheral Chemoreflex Sensitivity in a FASTK-Deficient Mice Model - PubMed
The molecular mechanisms underlying O|sub|2|/sub|-sensing by carotid body (CB) chemoreceptors remain undetermined. Mitochondria have been implicated, due to the sensitivity of CB response to electron transport chain (ETC) blockers. ETC is one of the major sources of reactive oxygen species, proposed …
https://pubmed.ncbi.nlm.nih.gov/30357733/?from_term=Simarro+M%5Bau%5D&from_pos=4
Synaptic excitation and inhibition resulting from direct action of acetylcholine on two types of chemoreceptors on individual...Synaptic excitation and inhibition resulting from direct action of acetylcholine on two types of chemoreceptors on individual...
Read Synaptic excitation and inhibition resulting from direct action of acetylcholine on two types of chemoreceptors on individual amphibian parasympathetic neurones, The Journal of Physiology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
https://www.deepdyve.com/lp/wiley/synaptic-excitation-and-inhibition-resulting-from-direct-action-of-JQOHoYsZj8
Signaling by the Escherichia coli Aspartate Chemoreceptor Tar with a Single Cytoplasmic Domain per Dimer | ScienceSignaling by the Escherichia coli Aspartate Chemoreceptor Tar with a Single Cytoplasmic Domain per Dimer | Science
Many transmembrane receptors are oligomeric proteins. Binding of a ligand may alter the oligomeric state of the receptor, induce structural changes within the oligomer, or both. The bacterial aspartate chemoreceptor Tar forms a homodimer in the presence or absence of ligands. Tar mediates attractant and repellent responses by modulating the activity of the cytoplasmic kinase CheA. In vivo intersubunit suppression was used to show that certain combinations of full-length and truncated mutant Tar proteins complemented each other to restore attractant responses to aspartate. These results suggest that heterodimers with only one intact cytoplasmic domain are functional. The signaling mechanism may require interactions between dimers or conformational changes within a single cytoplasmic domain.. ...
https://science.sciencemag.org/content/274/5286/423?ijkey=08bb2d0a72c145eb80afaac991569a48a1d42c39&keytype2=tf_ipsecsha
Human obesity is characterized by a selective potentiation of central chemoreflex sensitivity<...
TY - JOUR. T1 - Human obesity is characterized by a selective potentiation of central chemoreflex sensitivity. AU - Narkiewicz, Krzysztof. AU - Kato, Masahiko. AU - Pesek, Catherine A.. AU - Somers, Virend K.. PY - 1999/5. Y1 - 1999/5. N2 - The chemoreflexes are an important mechanism for regulation of both breathing and autonomic cardiovascular function. Obesity is associated with an increased risk of alveolar hypoventilation and carbon dioxide retention, suggesting that abnormalities in chemoreflex control mechanisms may be implicated. We tested the hypothesis that chemoreflex function is altered in obesity. We compared ventilatory, sympathetic, heart rate, and blood pressure responses to hypercapnia, hypoxia, and the cold pressor test in 14 obese subjects and 14 normal-weight subjects matched for age and gender. During hypercapnia, the increase in minute ventilation was significantly greater in obese subjects (7.0±0.3 L/min) than in normal-weight subjects (3.3±1.1 L/min; P=0.03). Despite ...
https://mayoclinic.pure.elsevier.com/en/publications/human-obesity-is-characterized-by-a-selective-potentiation-of-cen
human respiratory system - Chemoreceptors | physiology | Britannica.comhuman respiratory system - Chemoreceptors | physiology | Britannica.com
human respiratory system - Chemoreceptors: One way in which breathing is controlled is through feedback by chemoreceptors. There are two kinds of respiratory chemoreceptors: arterial chemoreceptors, which monitor and respond to changes in the partial pressure of oxygen and carbon dioxide in the arterial blood, and central chemoreceptors in...
https://www.britannica.com/science/human-respiratory-system/Chemoreceptors
Abstract 2470: Augmented Tonic Activation Of Chemoreceptors May Contribute To Sympathetic Overactivity In Patients With...Abstract 2470: Augmented Tonic Activation Of Chemoreceptors May Contribute To Sympathetic Overactivity In Patients With...
Rationale: Peripheral chemoreflex contributes to regulation of arterial blood pressure and chemoreceptors respond not only to hypoxia but they are also continuously activated by normal ambient oxygen concentration. Stimulation of chemoreceptors activates sympathetic traffic and this response may be altered in subjects with essential hypertension... Objective: The aim of our study was to investigate the effect of deactivation of carotid body chemoreceptors on sympathetic activity directly measured as MSNA (muscle sympathetic nerve activity) in young subjects with mild to moderate untreated hypertension.. Methods: Twelve patients with essential hypertension (36±9 years, all men, BMI 29±4 kg/m2,) and 8 controls (37±7, men BMI 27±5kg/m2) participated in the study. None of the patients or controls received any medications. MSNA (burst/minute and mean burst amplitude - au), systolic blood pressure (SBP) and diastolic blood pressure (DBP), heart rate (HR), ECG, hemoglobin saturation with oxygen ...
http://circ.ahajournals.org/content/118/Suppl_18/S_732.2
Search Results for pseudogene | AKJournalsSearch Results for pseudogene | AKJournals
Campylobacter jejunis flagellar locomotion is controlled by eleven chemoreceptors. Assessment of the distribution of the relevant chemoreceptor genes in the C. jejuni genomes deposited in the National Center for Biotechnology Information (NCBI) database led to the identification of two previously unknown tlp genes and a tlp5 pseudogene. These two chemoreceptor genes share the same locus in the C. jejuni genome with tlp4 and tlp11, but the gene region encoding the periplasmic ligand binding domain differs significantly from other chemoreceptor genes. Hence, they were named tlp12 and tlp13.. Consequently, it was of interest to study their distribution in C. jejuni subpopulations of different clonality, and their cooccurrence with the eleven previously reported chemoreceptor genes. Therefore, the presence of all tlp genes was detected by polymerase chain reaction (PCR) in 292 multilocus sequence typing (MLST)-typed C. jejuni isolates from different hosts.. The findings show interesting trends: ...
https://akjournals.com/search?pageSize=10&q=%22pseudogene%22&sort=relevance
Central chemoreceptors - WikipediaCentral chemoreceptors - Wikipedia
are not able to diffuse across the blood-brain barrier into the CSF. Only CO2 levels affect this as it can diffuse across, reacting with H2O to form carbonic acid and thus decrease pH. Central chemoreception remains, in this way, distinct from peripheral chemoreceptors. The central chemoreception system has also been shown experimentally to respond to hypercapnic hypoxia (elevated CO2, decreased O2) and aqueous sodium cyanide injection into the whole animal[1] and in vitro slice preparation. These methods can be used to mimic some forms of hypoxic hypoxia and they are currently being studied including the detection of variation in arterial CO2 tension acting as a quick-response-system for short term (or emergency) regulation. This system utilizes a negative feedback system, therefore if the pH of the cerebral spinal fluid does not compare to an ideal set level, then the receptor will send an error signal to the effectors and appropriate action may be executed. Peripheral chemoreceptors ...
https://en.wikipedia.org/wiki/Central_chemoreceptors
Chemoreceptors synonyms, Chemoreceptors antonyms - FreeThesaurus.comChemoreceptors synonyms, Chemoreceptors antonyms - FreeThesaurus.com
Synonyms for Chemoreceptors in Free Thesaurus. Antonyms for Chemoreceptors. 9 words related to chemoreceptor: sense organ, sensory receptor, receptor, gustatory organ, taste bud, tastebud, carotid body, nose, olfactory organ. What are synonyms for Chemoreceptors?
http://www.freethesaurus.com/Chemoreceptors
Frontiers | Metabolic Value Chemoattractants Are Preferentially Recognized at Broad Ligand Range Chemoreceptor of Pseudomonas...Frontiers | Metabolic Value Chemoattractants Are Preferentially Recognized at Broad Ligand Range Chemoreceptor of Pseudomonas...
Bacteria have evolved a wide range of chemoreceptors with different ligand specificities. Typically, chemoreceptors bind ligands with elevated specificity and ligands serve as growth substrates. However, there is a chemoreceptor family that has a broad ligand specificity including many compounds that are not of metabolic value. To advance the understanding of this family, we have used the PcaY_PP (PP2643) chemoreceptor of Pseudomonas putida KT2440 as a model. Using Isothermal Titration Calorimetry we showed here that the recombinant ligand binding domain (LBD) of PcaY_PP recognizes 17 different C6-ring containing carboxylic acids with KD values between 3.7 and 138 µM and chemoeffector affinity correlated with the magnitude of the chemotactic response. Mutation of the pcaY_PP gene abolished chemotaxis to these compounds; phenotype that was restored following gene complementation. Growth experiments using PcaY_PP ligands as sole C-sources revealed functional relationships between their metabolic
https://www.frontiersin.org/articles/10.3389/fmicb.2017.00990/full
What are Chemoreceptors? (with pictures)What are Chemoreceptors? (with pictures)
Chemoreceptors are specialized nerve cells designed to respond to chemical stimuli. There are two types of chemoreceptors in the...
http://www.wisegeek.org/what-are-chemoreceptors.htm
ANZCTR - Registration
Our extensive work in hypertensive animal models indicates that the carotid bodies develop tonicity and heightened reflex sensitivity due to excessive ATP bioavailability acting via purinergic (P2) receptors, which drive sympathetic outflows. We wish to determine whether a non-selective P2 receptor blocker reduces peripheral chemoreflex sensitivity, sympathetic activity, venous tone and blood pressure in humans with hypertension ...
https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=380394
Expression of taste receptors in solitary chemosensory cells of rodent airways. - PubMed - NCBIExpression of taste receptors in solitary chemosensory cells of rodent airways. - PubMed - NCBI
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
https://www.ncbi.nlm.nih.gov/pubmed/21232137?dopt=Abstract
Contribution of Tonic Chemoreflex Activation to Sympathetic Activity and Blood Pressure in Patients With Obstructive Sleep...Contribution of Tonic Chemoreflex Activation to Sympathetic Activity and Blood Pressure in Patients With Obstructive Sleep...
This double-blind, randomized, vehicle-controlled study indicates that chemoreflex deactivation with hyperoxia decreases MSNA and blood pressure in normoxic, normotensive patients with OSA but not in normal, obese control subjects. Thus, elevated sympathetic nerve activity to muscle in patients with OSA might be explained in part by tonic activation of excitatory chemoreflex afferents.. Studies in animals indicate that tonic chemoreflex activation even during normoxia has significant effects on both blood pressure and heart rate, probably mediated by sympathetic activation.9 Previous studies in humans show that 100% oxygen elicits reductions in MSNA and not blood pressure, but in normal-weight young subjects.6 Another possible explanation for the previously observed decrease in MSNA during 100% oxygen in normal subjects might be acclimation to the laboratory setting and to mouthpiece breathing. In the present study, 100% oxygen decreased MSNA and MAP in both normal obese control subjects and ...
http://circ.ahajournals.org/content/97/10/943
Chemoreception | Encyclopedia.com
CHEMORECEPTION CONCEPT Chemoreception is a physiological process whereby organisms respond to chemical stimuli. Humans and most higher animals have two principal classes of chemoreceptors: taste (gustatory receptors), and smell (olfactory receptors).
https://www.encyclopedia.com/science-and-technology/chemistry/chemistry-general/chemoreception
Latest findings | Krell laboratoryLatest findings | Krell laboratory
We show CheR2 was the only paralogue that methylated McpB, and deletion of the pentapeptide abolished both the CheR2-McpB interaction and the methylation of McpB. The cheR2 and mcpB genes are vicinal in the P. aeruginosa genome and form part of the gene cluster that encodes the Che2 chemosensory pathway. We conclude that the CheR-pentapeptide interaction enabled the specific targeting of one CheR methyltransferase to one chemoreceptor. We also found that bacterial CheR proteins form two distinct protein families when clustered according to sequence, those that bind pentapeptide-containing chemoreceptors and those that do not, distinguished by an insertion of three amino acids in the β-subdomain of CheR. Deletion of this insertion in CheR2 prevented its interaction with and methylation of McpB. Because many bacteria contain pentapeptide-containing chemoreceptors and several signaling protein paralogues, we predict that the mechanism described may contribute to the specific assembly of signaling ...
https://krell-laboratory.com/latest-findings/
A whole-body approach to understanding chemosensory cellsA whole-body approach to understanding chemosensory cells
Growing evidence shows that sensory cells which enable us to taste sweetness, bitterness and savoriness (umami) are not limited to the tongue. These so-called Trpm5-expressing chemosensory cells are also found in the respiratory ...
https://phys.org/news/2017-12-whole-body-approach-chemosensory-cells.html
STOMACH by Jaymee Bayro on PreziSTOMACH by Jaymee Bayro on Prezi
2.) Chemoreceptors in the duodenum are stimulated by H+ (low pH) or lipids. Action potentials generated by the chemoreceptors are carried by the vagus nerves to the medulla oblongata (green arrow), where they inhibit parasympathetic action potentials (pink arrow), thereby decreasing gastric secretions ...
https://prezi.com/x6pmcjenpqrx/stomach/
Asymmetric polar localization dynamics of the serine chemoreceptor protein Tsr in Escherichia coli | ScholarBank@NUSAsymmetric polar localization dynamics of the serine chemoreceptor protein Tsr in Escherichia coli | [email protected]
The spatial location of proteins in living cells can be critical for their function. For example, the E. coli chemotaxis machinery is localized to the cell poles. Here we describe the polar localization of the serine chemoreceptor Tsr using a strain synthesizing a fluorescent Tsr-Venus fusion at a low level from a single-copy chromosomal construct. Using photobleaching and imaging during recovery by new synthesis, we observed distinct asymmetry between a bright (old) pole and a dim (new) pole. The old pole was shown to be a more stable cluster and to recover after photobleaching faster, which is consistent with the hypothesis that newly synthesized Tsr proteins are inserted directly at or near the old pole. The new pole was shown to be a less stable cluster and to exchange proteins freely with highly mobile Tsr-Venus proteins diffusing in the membrane. We propose that the new pole arises from molecules escaping from the old pole and diffusing to the new pole where a more stable cluster forms ...
https://scholarbank.nus.edu.sg/handle/10635/161225
Clinical Tip - Avoiding Opioid-Related Respiratory Depression | Physician-Patient Alliance for Health & SafetyClinical Tip - Avoiding Opioid-Related Respiratory Depression | Physician-Patient Alliance for Health & Safety
There are indeed numerous deaths due to synergistic combinations of sedatives and opioids. This is because sedatives obtund the primary form of respiratory drive, and opioids obtund the secondary form of respiratory drive. If both forms of respiratory drive are blocked, then respiratory drive is abolished altogether, which of course is lethal. The primary form of respiratory drive is affected by pH receptors in brain ventricles, and it determines respiratory rate and depth in conscious individuals. This form of respiratory drive is resistant to hyperventilation and depletion of CO2 tissue reserves so long as consciousnss remains present. During sleep and anesthesia, when consciousness is obtunded, the primary respiratory drive is abolished, and breathing becomes totally dependent on the secondary form of respiratory drive. The secondary form of respiratory drive is primarily determined by respiratory chemoreceptors located in extravascular tissues. These are stimulated directly by hypercarbia, ...
http://ppahs.org/2017/10/clinical-tip-avoid-opioid-related-respiratory-depression/
RNAiDB Tree View
C. elegans STR-8 protein; contains similarity to Pfam domain PF01461 (7TM chemoreceptor)contains similarity to Interpro domains IPR000168 (Nematode 7TM chemoreceptor (probably olfactory)), IPR003002 (7TM chemoreceptor, subfamily 1 ...
http://aquila.bio.nyu.edu/cgi-bin/rnaidb/ace/tree?name=T23D5.11&class=CDS&squash=GO_term&squash=Corresponding_RNAi_reagent&expand=Visible&expand=WB_RNAi_result
Evolution and Design Governing Signal Precision and Amplification in a Bacterial Chemosensory Pathway | proLékárníky.czEvolution and Design Governing Signal Precision and Amplification in a Bacterial Chemosensory Pathway | proLékárníky.cz
1. Salazar ME, Laub MT. Temporal and evolutionary dynamics of two-component signaling pathways. Curr Opin Microbiol. 2015;24: 7-14. doi: 10.1016/j.mib.2014.12.003 25589045. 2. Tian T, Harding A. How MAP kinase modules function as robust, yet adaptable, circuits. Cell Cycle. 2014;13: 2379-2390. doi: 10.4161/cc.29349 25483189. 3. Capra EJ, Perchuk BS, Skerker JM, Laub MT. Adaptive mutations that prevent crosstalk enable the expansion of paralogous signaling protein families. Cell. 2012;150: 222-232. doi: 10.1016/j.cell.2012.05.033 22770222. 4. Jonas K, Chen YE, Laub MT. Modularity of the bacterial cell cycle enables independent spatial and temporal control of DNA replication. Curr Biol. 2011;21: 1092-1101. doi: 10.1016/j.cub.2011.05.040 21683595. 5. Murray SM, Panis G, Fumeaux C, Viollier PH, Howard M. Computational and genetic reduction of a cell cycle to its simplest, primordial components. PLoS Biol. 2013;11: e1001749. doi: 10.1371/journal.pbio.1001749 24415923. 6. Stock AM, Robinson VL, ...
https://www.prolekarniky.cz/casopisy/plos-genetics/2015-8/evolution-and-design-governing-signal-precision-and-amplification-in-a-bacterial-chemosensory-pathway-55300
Cholinergic chemosensory cells in the trachea regulate breathingCholinergic chemosensory cells in the trachea regulate breathing
Publikations-Datenbank der Fraunhofer Wissenschaftler und Institute: Aufsätze, Studien, Forschungsberichte, Konferenzbeiträge, Tagungsbände, Patente und Gebrauchsmuster
http://publica.fraunhofer.de/dokumente/N-189831.html
Recent Articles | Chemoreception And Ecology | The Scientist Magazine®Recent Articles | Chemoreception And Ecology | The Scientist Magazine®
Daily News How Gaining and Losing Weight Affects the Body Millions of measurements from 23 people who consumed extra calories every day for a month reveal changes in proteins, metabolites, and gut microbiota that accompany shifts in body mass.. ...
https://www.the-scientist.com/?articles.list/categoryNo/2625/category/The-Scientist/tagNo/3392,7/tags/chemoreception,ecology/
Positioning of chemosensory clusters in E. coli and its relation to cell division | The EMBO Journal
Recent studies revealed a high degree of spatial organisation in bacterial cells, and positioning of the chemoreceptor clusters does not appear to be an exception. Lateral clusters are distributed along the cell body in a periodic manner, with the peak positions roughly corresponding to 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, and 7/8 of the distance between polar regions. Such periodicity suggests an anchorage to some hypothetical structure, which is further supported by the apparent immobility of lateral clusters. Our results make it unlikely that this structure relies directly on either the Min septum positioning system or the MreB cytoskeleton, although cluster positioning was affected by a loss of the rod shape upon a long‐term treatment with the MreB inhibitor A22. At the current stage, we can only speculate about the nature of this structure. Many protein complexes in bacteria appear to localise along helical filaments, and it has been recently shown that receptors become inserted into the ...
http://emboj.embopress.org/content/26/6/1615
Publications | Page 3 | Cervo Brain Research CentrePublications | Page 3 | Cervo Brain Research Centre
Bairam A, Dauphin C, Rousseau F, Khandjian EW. Expression of dopamine D2-receptor mRNA isoforms at the peripheral chemoreflex afferent pathway in developing rabbits. Am J Respir Cell Mol Biol. 1996;15(3):374-81. ...
https://cervo.ulaval.ca/en/publications?page=2&%3Bamp%3Bf%5Bauthor%5D=859&%3Bf%5Bauthor%5D=5154&f%5Bauthor%5D=1168
Gene transfer of neuronal nitric oxide synthase to carotid body reverses enhanced chemoreceptor function in heart failure...
TY - JOUR. T1 - Gene transfer of neuronal nitric oxide synthase to carotid body reverses enhanced chemoreceptor function in heart failure rabbits. AU - Li, Yulong. AU - Li, Yi Fan. AU - Liu, Dongmei. AU - Cornish, Kurtis G.. AU - Patel, Kaushik P. AU - Zucker, Irving H. AU - Channon, Keith M.. AU - Schultz, Harold D. PY - 2005/8/5. Y1 - 2005/8/5. N2 - Our previous studies showed that decreased nitric oxide (NO) production enhanced carotid body (CB) chemoreceptor activity in chronic heart failure (CHF) rabbits. In the present study, we investigated the effects of neuronal NO synthase (nNOS) gene transfer on CB chemoreceptor activity in CHF rabbits. The nNOS protein expression and NO production were suppressed in CBs (P,0.05) of CHF rabbits, but were increased 3 days after application of an adenovirus expressing nNOS (Ad.nNOS) to the CB. As a control, nNOS and NO levels in CHF CBs were not affected by Ad.EGFP. Baseline single-fiber discharge during normoxia and the response to hypoxia were ...
https://nebraska.pure.elsevier.com/en/publications/gene-transfer-of-neuronal-nitric-oxide-synthase-to-carotid-body-r
British Library EThOS: A neuropharmcological study of some aspects of carotid body chemoreceptor activity in the catBritish Library EThOS: A neuropharmcological study of some aspects of carotid body chemoreceptor activity in the cat
Afferent chemoreceptor activity was recorded from the peripheral cut end of the carotid sinus nerve in pentobarbitone anaesthetized cats. The effects of purines, peptides and ouabain on chemosensory activity were studied. Purines. It was found that intracarotid injections of adenosine: AMP; ADP; ATP; CoA;Me-adenosine analogues: N6-methyladenosine, 2-chloroadenosine, 3-deoxyudenosine but not 2-deoxyadenosine; cyclic AMP; dibutyryl cyclic AMP increased spontaneous chemoreceptor discharge. The ATP analogues, a-5- methylene ATP decreased spontaneous chemoreceptor discharge, whereas the f-y-methylene ATP caused a slight increase in discharge. Adenine and the purine nucleosides inosine and guanosine had little or no effect on the discharge. The pyrimidine nucleosides cytidine and uridine were also studied and had little or no effect on spontaneous chemoreceptor discharge. Intracarotid injection of theophylline transiently depressed spontaneous chemosensory activity and potentiated the action of ...
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.661090
Role of Chemoreceptor Activation in Hemodynamic Responses to Electrical Stimulation of the Carotid Sinus in Conscious...Role of Chemoreceptor Activation in Hemodynamic Responses to Electrical Stimulation of the Carotid Sinus in Conscious...
The major new finding obtained from conscious rats was the clear-cut demonstration that chemoreceptors, as well as baroreceptors, were transiently activated during combined electric stimulation of the carotid sinus and the carotid sinus nerve in conscious rats. The results have shown that when the carotid bifurcation was intact (ie, in the CONT group), combined electric stimulation of the carotid sinus and the carotid sinus nerve elicited a significant hypotensive response. This finding is in line with results obtained in dogs21,22 and drug-resistant hypertensive patients.1,2 Nevertheless, unlike the results seen in dogs23 and drug-resistant hypertensive patients,4 HR did not significantly decrease in intact conscious rats (the CONT group).. It is of interest to note that bilateral carotid body denervation (as in the CHEMO-X group) hampered the hemodynamic influences of the carotid chemoreceptors during combined electric stimulation of the carotid sinus and the carotid sinus nerve in conscious ...
http://hyper.ahajournals.org/content/66/3/598
Bicarbonate-regulated soluble adenylyl cyclase (sAC) mRNA expression and activity in peripheral chemoreceptors<...
TY - GEN. T1 - Bicarbonate-regulated soluble adenylyl cyclase (sAC) mRNA expression and activity in peripheral chemoreceptors. AU - Nunes, A. R.. AU - Monteiro, E. C.. AU - Johnson, S. M.. AU - Gauda, E. B.. PY - 2009/12. Y1 - 2009/12. N2 - Peripheral arterial chemoreceptors in the carotid body (CB) are modulated by pH/CO2. Soluble adenylyl cyclase (sAC) is directly stimulated by bicarbonate ions (HCO3 -). Because CO2/HCO 3 - mediates depolarization in chemoreceptors, we hypothesized that sAC mRNA would be expressed in the CB, and its expression and function would be regulated by CO2/HCO3 -. Sprague-Dawley rats at postnatal days 16-17 were used to compare sAC mRNA gene expression between CB and non-chemosensitive tissues: superior cervical (SCG), petrosal (PG) and nodose ganglia (NG) by quantitative real time-PCR. Rat sAC gene expression was standardized to the expression of GAPDH (housekeeping gene) and the data were analyzed with the Pfaffl method. Gene and protein expression, and sAC ...
https://puredev.unl.pt/en/publications/bicarbonate-regulated-soluble-adenylyl-cyclase-sac-mrna-expressio
Ventilation- and carotid chemoreceptor discharge-response to hypoxia during induced hypothermia in halothane anesthetized rat<...
TY - JOUR. T1 - Ventilation- and carotid chemoreceptor discharge-response to hypoxia during induced hypothermia in halothane anesthetized rat. AU - Maruyama, Ryoko. AU - Fukuda, Yasuichiro. N1 - Copyright: Copyright 2017 Elsevier B.V., All rights reserved.. PY - 2000/2. Y1 - 2000/2. N2 - It has been hypothesized that respiratory gain to hypoxic stimulus is not depressed in hypothermic animals though ventilation and that metabolic O2 demand (VO2) decreases with reduction in body temperature. The present study addressed this hypothesis by quantitative analysis of ventilatory and carotid chemoreceptor responsiveness to hypoxia during induced hypothermia in halothane anesthetized and spontaneously breathing rats. Rectal temperature was lowered from 37 °C (normothermia) to 30 and 25 °C by cooling body surface at comparable anesthetic depth without inducing shivering. Ventilation (VE), VO2, Pao2 and carotid chemoreceptor afferent discharges were measured during hyperoxic and hypoxic gas breathing. ...
https://tohoku.pure.elsevier.com/en/publications/ventilation-and-carotid-chemoreceptor-discharge-response-to-hypox
Carotid Body Chemoreceptor Function Is Impaired by Vecuronium during Hypoxia | Anesthesiology | ASA PublicationsCarotid Body Chemoreceptor Function Is Impaired by Vecuronium during Hypoxia | Anesthesiology | ASA Publications
The study was approved by the Local Animal Care and Use Committee of the Karolinska Institute, Stockholm, Sweden. Seven adult New Zealand White rabbits weighing 3860 +/− 270 g (mean +/− SD) were included. After an initial dose of intravenous thiopental, 75-100 mg, given via a marginal ear vein, a tracheostomy was performed after an anterior midline skin incision. Mechanical ventilation (ETCO(2), 4.0-5.0%) was initiated at a rate of 33 breaths/min using a mixture of oxygen and air (FIO(2) 0.30), whereas the inspired tidal volume was adjusted to maintain isocapnia throughout the experiment. Anesthesia was maintained with a continuous thiopental infusion of 10.5 +/− 0.9 mg [middle dot] kg-1[middle dot] h-1(range, 9.4-12.0) given via a right femoral vein catheter. The right femoral artery was cannulated for continuous arterial blood pressure monitoring and arterial blood gas analysis (ABL 300 Laboratory [registered sign], Radiometer, Copenhagen, Denmark). On-line analysis of inspired and ...
http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1946760
Chemoreceptive | Article about chemoreceptive by The Free DictionaryChemoreceptive | Article about chemoreceptive by The Free Dictionary
Looking for chemoreceptive? Find out information about chemoreceptive. The ability of organisms to detect changes in the chemical composition of their exterior or interior environment. It is a characteristic of every living... Explanation of chemoreceptive
https://encyclopedia2.thefreedictionary.com/chemoreceptive
Modulation of peripheral chemoreflex by neurohumoral adaptations after kidney transplantation - Surrey Research Insight Open...Modulation of peripheral chemoreflex by neurohumoral adaptations after kidney transplantation - Surrey Research Insight Open...
Background. Peripheral chemoreceptors residing predominantly in the carotid body monitor changes in arterial blood oxygen and are mechanistically linked to the cardiorespiratory control by the autonomic nervous system. Enhanced sympathetic activation is common in end-stage renal disease and kidney transplantation has been shown to improve cardiorespiratory reflex measures of autonomic function.. Objective. The aim of the present study was to test whether improvement in renal function following kidney transplantation is related to an improvement in chemosensory function.. Methods and Results. We compared hyperoxic chemoreflex sensitivity (CHRS) in patients after renal transplantation (RTX) to that in patients on maintenance hemodialysis (HD), and that of age- and gender-matched healthy controls. In addition, we investigated the impact of common confounding factors including pharmacological neurohumoral modulation and diabetes mellitus. The difference in the R-R intervals divided by the difference ...
https://epubs.surrey.ac.uk/848952/
Acid-base homeostasis
The pH of the extracellular fluids can thus be controlled by separately regulating the partial pressure of carbon dioxide (which determines the carbonic acid concentration), and the bicarbonate ion concentration in the extracellular fluids. There are therefore at least two homeostatic negative feedback systems responsible for the regulation of the plasma pH. The first is the homeostatic control of the blood partial pressure of carbon dioxide, which determines the carbonic acid concentration in the plasma, and can change the pH of the arterial plasma within a few seconds.[5] The partial pressure of carbon dioxide in the arterial blood is monitored by the central chemoreceptors of the medulla oblongata, and so are part of the central nervous system.[5][19] These chemoreceptors are sensitive to the pH and levels of carbon dioxide in the cerebrospinal fluid.[13][11][19] (The peripheral chemoreceptors are located in the aortic bodies and carotid bodies adjacent to the arch of the aorta and to the ...
https://readtiger.com/wkp/en/Acid%E2%80%93base_homeostasis
Analysis of Mutations in the Transmembrane Region of the Aspartate Chemoreceptor in Escherichia coli - CaltechAUTHORSAnalysis of Mutations in the Transmembrane Region of the Aspartate Chemoreceptor in Escherichia coli - CaltechAUTHORS
Site-specific mutagenesis was used to replace an alanine with a lysine residue and to create a deletion of seven amino acids into the first transmembrane region (TMI region) of the aspartate chemoreceptor in Escherichia coli. The mutations resulted in the loss of aspartate chemotaxis on tryptone motility plates. However, both mutant proteins were able to associate with the membrane and to bind aspartate. They were both refractory to methylation or to modification of the C-terminal region of the protein by the cheB gene product. These results suggested that the integrity of the TMI domain of the protein was required to maintain the function of the cytoplasmic portion of the receptor. The Lys-19 mutant retained the ability to generate a repellent response. Analysis of suppressor mutations of the Lys-19 mutation suggested that formation of an ion pair or specific changes in a 40 amino acid stretch in the cytoplasmic region of the protein (from amino acid 264 to amino acid 303) could suppress the ...
https://authors.library.caltech.edu/5778/
Carotid body: a new target for rescuing neural control of cardiorespiratory balance in disease | Frontiers Research TopicCarotid body: a new target for rescuing neural control of cardiorespiratory balance in disease | Frontiers Research Topic
The carotid body (CB) is the main arterial chemoreceptor in charge of adjusting ventilatory and cardiovascular function during changes in arterial blood gases. Regardless this essential function, the CB has been implicated in the sensing of other physiological signals such as changes in blood flow and glucose levels. More important, malfunction of the CB chemoreceptors has been associated with the progression and deterioration of several disease states such as hypertension, heart failure, renal failure, insulin resistance, diabetes and sleep apnea. Although the mechanisms involved in the alterations of the CB function in pathophysiology are currently under intense research, the development of therapeutic approaches to restore normal CB chemoreflex function remains unsolved. Recently, elegant studies showing the effect of CB neurotomy in pathophysiology have unveiled a key role of these arterial chemoreceptors in the development of autonomic imbalance and respiratory disturbances, and suggest that
https://www.frontiersin.org/research-topics/2694/carotid-body-a-new-target-for-rescuing-neural-control-of-cardiorespiratory-balance-in-disease
Cholinergic chemosensory cells in the trachea regulate breathing<...
TY - JOUR. T1 - Cholinergic chemosensory cells in the trachea regulate breathing. AU - Krasteva, Gabriela. AU - Canning, Brendan J. AU - Hartmann, Petra. AU - Veres, Tibor Z.. AU - Papadakis, Tamara. AU - Mühlfeld, Christian. AU - Schliecker, Kirstin. AU - Tallini, Yvonne N.. AU - Braun, Armin. AU - Hackstein, Holger. AU - Baal, Nelli. AU - Weihe, Eberhard. AU - Schütz, Burkhard. AU - Kotlikoff, Michael. AU - Ibanez-Tallon, Ines. AU - Kummer, Wolfgang. PY - 2011/6/7. Y1 - 2011/6/7. N2 - In the epithelium of the lower airways, a cell type of unknown function has been termed brush cell because of a distinctive ultrastructural feature, an apical tuft of microvilli. Morphologically similar cells in the nose have been identified as solitary chemosensory cells responding to taste stimuli and triggering trigeminal reflexes. Here we show that brush cells of the mouse trachea express the receptors (Tas2R105, Tas2R108), the downstream signaling molecules (α-gustducin, phospholipase Cβ2) of bitter ...
https://jhu.pure.elsevier.com/en/publications/cholinergic-chemosensory-cells-in-the-trachea-regulate-breathing-5
adam respiration lab 21
The basic rythum of breathing is controlled by respiratory centers located in the medulla and pons of the brainstem. This rythum is modified in response to input from sensory receptors and from other regions of the brain. Respiratory centers in the pons modify inspiration and allow for smooth transitions between inspiration and expiation. Expiratory centers in the medulla function during forced expiation stimulating the internal and abdominal muscles. The basic rythum of breathing is modified by input from the central and peripheral chemoreceptors. They respond to changes in the PCO2 and PO2 of arterial blood. Medullary chemoreceptors are located on the ventral surface of the medulla oblongata. The medullary chemoreceptors detect changes to the H+ concentration of the brain interstitial fluid, an indirect assessment of arterial PCO2. Chemoreceptors in the carotid and aortic bodies are stimulated by a rise in the PCO2, a rise in the H+ concentration, or a decline in arterial blood PO2. Peripheral ...
http://wickersham.us/anne/respiration.htm
PHD2 inactivation in Type I cells drives HIF-2α-dependent multilineage hyperplasia and the formation of paraganglioma-like...PHD2 inactivation in Type I cells drives HIF-2α-dependent multilineage hyperplasia and the formation of paraganglioma-like...
KEY POINTS: The carotid body is a peripheral arterial chemoreceptor that regulates ventilation in response to both acute and sustained hypoxia. Type I cells in this organ respond to low oxygen both acutely by depolarization and dense core vesicle secretion and, over the longer term, via cellular proliferation and enhanced ventilatory responses. Using lineage analysis, the present study shows that the Type I cell lineage itself proliferates and expands in response to sustained hypoxia. Inactivation of HIF-2α in Type I cells impairs the ventilatory, proliferative and cell intrinsic (dense core vesicle) responses to hypoxia. Inactivation of PHD2 in Type I cells induces multilineage hyperplasia and ultrastructural changes in dense core vesicles to form paraganglioma-like carotid bodies. These changes, similar to those observed in hypoxia, are dependent on HIF-2α. Taken together, these findings demonstrate a key role for the PHD2-HIF-2α couple in Type I cells with respect to the oxygen sensing functions
https://www.rdm.ox.ac.uk/publications/858422
Control of ventilation - WikipediaControl of ventilation - Wikipedia
The control of ventilation refers to the physiological mechanisms involved in the control of breathing, which is the movement of air into and out of the lungs. Ventilation facilitates respiration. Respiration refers to the utilization of oxygen and removal of carbon dioxide by the body as a whole, or by individual cells in cellular respiration. The most important function of breathing is the supplying of oxygen to the body and the removal of its waste product of carbon dioxide. Under most conditions, the partial pressure of carbon dioxide (PCO2) or concentration of carbon dioxide, controls the respiratory rate. The peripheral chemoreceptors that detect changes in the levels of oxygen and carbon dioxide are located in the arterial aortic bodies and the carotid bodies. Central chemoreceptors are primarily sensitive to changes in the pH in the blood, (resulting from changes in the levels of carbon dioxide) and they are located on the medulla oblongata near to the medullar respiratory groups of the ...
https://en.wikipedia.org/wiki/Control_of_ventilation
DOAB: Directory of Open Access BooksDOAB: Directory of Open Access Books
Abstract. The carotid body (CB) is in charge of adjusting ventilatory and cardiovascular function during changes in arterial blood gases. Regardless this essential function, the CB has been implicated in the sensing of other physiological signals such as changes in blood flow and glucose levels. More important, malfunction of the CB chemoreceptors has been associated with the progression and deterioration of several disease states such as hypertension, heart failure, renal failure, insulin resistance, diabetes and sleep apnea. Although the mechanisms involved in the alterations of the CB function in pathophysiology are currently under intense research, the development of therapeutic approaches to restore normal CB chemoreflex function remains unsolved. Recent studies showing the effect of CB denervation in pathophysiology have unveiled a key role of these arterial chemoreceptors in the development of autonomic imbalance and respiratory disturbances, and suggest that targeting the CB could ...
https://doabooks.org/doab?func=search&minusFilter=utlic:%22CC%20by-nc-nd%22&template=&query=kw%3A%22Sleep%22&fromYear=&uiLanguage=en&toYear=&filter=utlic%3A%22CC%20by-nc-nd%22
dentalaka: Physiology of Ventilatory System (Pulmonary Physiology)
Monitored by peripheral chemoreceptors - carotid/aortic bodies. Not sensitive to modest changes in PO2. Arterial PO2 must be , 60 mmHg (40% reduction) for chemoreceptors to send afferent impulses to medullary inspiratory neurons. (happens with severe pulmonary disease, reduced atmospheric pressure). Until you get to 60 mmHg, youre still in plateau range of Hb-O2 dissociation curve (safe). If it werent for peripheral chemoreceptors, the low PO2 would depress respiratory centers à stop breathing. Chemoreceptors respond to PO2, not oxygen content. Anemia, CO poisoning - PO2is normal, but total O2 is too low. ...
http://dentalaka.blogspot.ae/2014/03/physiology-of-ventilatory-system.html
PDF] The evolution of animal chemosensory receptor gene repertoires: roles of chance and necessity | Semantic ScholarPDF] The evolution of animal chemosensory receptor gene repertoires: roles of chance and necessity | Semantic Scholar
Chemosensory receptors are essential for the survival of organisms that range from bacteria to mammals. Recent studies have shown that the numbers of functional chemosensory receptor genes and pseudogenes vary enormously among the genomes of different animal species. Although much of the variation can be explained by the adaptation of organisms to different environments, it has become clear that a substantial portion is generated by genomic drift, a random process of gene duplication and deletion. Genomic drift also generates a substantial amount of copy-number variation in chemosensory receptor genes within species. It seems that mutation by gene duplication and inactivation has important roles in both the adaptive and non-adaptive evolution of chemosensation.
https://www.semanticscholar.org/paper/The-evolution-of-animal-chemosensory-receptor-gene-Nei-Niimura/cf3430c919abb5e1d2e372286b205070f1bee19c
Elizabeth F-Bailey | BIO5Elizabeth F-Bailey | BIO5
My research focus is the neural control of breathing in human and nonhuman mammals. My earlier work assessed the role of pulmonary stretch receptors and central chemoreceptors in the genesis and relief of dyspnea or shortness of breath in healthy adults. These studies led to studies in the mammalian (rodent) airway that explored the modulation of upper airway muscles activities by chemical and pulmonary afferent feedback and the potential for selective electrical stimulation of the cranial nerve XII to alter airway geometry and volume (NIH/NIDCD RO3). Beginning in 2005, with the support of an NIH/NIDCD K23 I began work in neural control of upper airway muscles using tungsten microelectrodes to record from single motor units in adult human subjects. This work led in turn, to studies of regional (or segmental) muscle and motor unit activities in human subjects under volitional, state-dependent (i.e., wake/sleep) and chemoreceptor drives, in health and disease (NIH/NIDCD RO1). On the basis of the ...
http://bio5.org/about/scientists/elizabeth-f-bailey
Stereospecificity of multiple receptor sites in a labellar sugar receptor of the fleshfly for amino acids and small peptides. |...Stereospecificity of multiple receptor sites in a labellar sugar receptor of the fleshfly for amino acids and small peptides. |...
N-Formylation and N-methylation of the alpha-amino group of L-phenylalanine result in extremely decreased responses of the labellar sugar receptor of the fleshfly, whereas the same structural alteration of L-valine hardly affects the response. Methyl esterification of the alpha-carboxyl group of phenylalanine, on the other hand, maintains the response to some extent, but similar treatment of valine completely diminishes the response. The aromatic structure in phenylalanine is not essential for stimulation. These results suggest a substantial difference in the stereospecificities and functional group specificities of the furnase (F) and aliphatic carboxylate (T) sites in the sugar receptor. The effect of small peptides on the sugar receptor was examined systematically. Their effectiveness depends mainly on the place of the constituent amino acids rather than on their composition, indicating the decisive role that certain aliphatic amino acids in the C-terminal position play in stimulation. ...
http://jgp.rupress.org/content/77/1/23
Plus itPlus it
The results from these studies demonstrate that afferent input from peripheral chemoreceptors and mechanoreceptors contributes little to the systemic hemodynamic and sympathetic responses after term delivery by cesarean section. Furthermore, birth-related increases in circulating norepinephrine but not epinephrine appear dependent on afferent input from the carotid sinus or aortic depressor nerves, which carry both chemo- and baroreceptor afferents from the carotid sinus and aortic arch, respectively. Finally, we observed that vagal afferent activity regulates basal fetal plasma ANG II levels and exerts a tonic inhibitory effect on AVP release after birth.. Both peripheral chemoreceptors and baroreceptors have been shown to be functional during fetal life. The fetal cardiovascular response to acute hypoxemia is well described, consisting of a decrease in heart rate and increase in peripheral vascular resistance (7). Carotid denervation abolishes these responses to hypoxemia and NaCN, a chemical ...
http://ajpregu.physiology.org/content/276/5/R1295
Most recent papers with the keyword Ventilatory drive | Read by QxMDMost recent papers with the keyword Ventilatory drive | Read by QxMD
Haldane and Priestley (1905) discovered that the ventilatory control system is highly sensitive to CO2. This CO2 chemoreflex has been interpreted to dominate control of resting arterial PCO2/pH (PaCO2/pHa) by monitoring PaCO2/pHa and altering ventilation through negative feedback. However, PaCO2/pHa varies little in mammals as ventilation tightly couples to metabolic demands, which may minimize chemoreflex control of PaCO2. The purpose of this synthesis is to (1) interpret data from experimental models with meager CO2 chemoreflexes to infer their role in ventilatory control of steady-state PaCO2, and (2) identify physiological causes of respiratory acidosis occurring normally across vertebrate classes ...
https://www.readbyqxmd.com/keyword/36761
Soluble proteins containing 4 conserved cysteines which abundantly exist in the chemoreceptive | GlyT1 inhibitor glyt1inhibitor...
Soluble proteins containing 4 conserved cysteines which abundantly exist in the chemoreceptive organs and transmit chemical signals to nervous system . The CSP
http://glyt1inhibitor.com/index.php/2017/08/18/soluble-proteins-containing-4-conserved-cysteines-which-abundantly-exist-in-the-chemoreceptive/
Chemosensors | Free Full-Text | Autonomous Oscillation of Nonthermoresponsive Polymers and Gels Induced by the Belousov...Chemosensors | Free Full-Text | Autonomous Oscillation of Nonthermoresponsive Polymers and Gels Induced by the Belousov...
This review introduces the self-oscillating behavior of two types of nonthermoresponsive polymer systems with Ru catalyst moieties for the Belousov-Zhabotinsky (BZ) reaction: one with a poly-vinylpyrrolidone (PVP) main chain, and the other with a poly(2-propenamide) (polyacrylamide) (PAM) main chain. The amplitude of the VP-based self-oscillating polymer chain and the activation energy for self-oscillation are hardly affected by the initial concentrations of the BZ substrates. The influences of the initial concentrations of the BZ substrates and the temperature on the period of the swelling-deswelling self-oscillation are examined in detail. Logarithmic plots of the period against the initial concentration of one BZ substrate, when the concentrations of the other two BZ substrates are fixed, show good linear relationships. The period of the swelling-deswelling self-oscillation decreases with increasing temperature, in accordance with the Arrhenius equation. The maximum frequency (0.5 Hz) of the poly(VP
http://www.mdpi.com/2227-9040/1/2/3/notes
Chemosensors | Free Full-Text | Toward Non-Enzymatic Ultrasensitive Identification of Single Nucleotide Polymorphisms by...Chemosensors | Free Full-Text | Toward Non-Enzymatic Ultrasensitive Identification of Single Nucleotide Polymorphisms by...
Single nucleotide polymorphisms (SNPs) are single nucleotide variations which comprise the most wide spread source of genetic diversity in the genome. Currently, SNPs serve as markers for genetic predispositions, clinically evident disorders and diverse drug responses. Present SNP diagnostics are primarily based on enzymatic reactions in different formats including sequencing, polymerase-chain reaction (PCR) and microarrays. In these assays, the enzymes are applied to address the required sensitivity and specificity when detecting SNP. On the other hand, the development of enzyme-free, simple and robust SNP sensing methods is in a constant focus in research and industry as such assays allow rapid and reproducible SNP diagnostics without the need for expensive equipment and reagents. An ideal method for detection of SNP would entail mixing a DNA or RNA target with a probe to directly obtain a signal. Current assays are still not fulfilling these requirements, although remarkable progress has been
http://www.mdpi.com/2227-9040/2/3/193/xml
ChemosensorsChemosensors
The 9th Catalysis and Sensing for our Environment Symposium (CASE 2019) and 2nd C5 Symposium on Supramolecular Chemistry will be held in Xian 14-16 April 2019 at Northwest A&F University http://en.nwsuaf.edu.cn/events/87816.htm http://en.nwsuaf.edu.cn/events/87815.htm. ...
http://blogs.bath.ac.uk/chemosensors/
Evidence for Glucose Uptake in the Rabbit Carotid Body | SpringerLinkEvidence for Glucose Uptake in the Rabbit Carotid Body | SpringerLink
The carotid body located in the bifurcation of the carotid arteries is able to detect gas changes in blood composition (PO2, PCO2/pH) and to transduce them into afferent nerve signal. The intimate...
https://link.springer.com/chapter/10.1007/978-1-4615-2966-8_16
vasodilation of artery during baroreceptor response to increased blood pressure QuickView - Correlation Engine
An increase in the internal diameter of an artery, triggered by vasomotor suppression, during the chemoreceptor response to decreased blood pressure.
http://www.nextbio.com/b/search/ov/vasodilation%20of%20artery%20during%20baroreceptor%20response%20to%20increased%20blood%20pressure?id=31561&type=biogroup
Purinergic regulation of vascular tone in the retrotrapezoid nucleus is specialized to support the drive to breathe | eLifePurinergic regulation of vascular tone in the retrotrapezoid nucleus is specialized to support the drive to breathe | eLife
CO2/H+-dependent purinergic signaling by astrocytes provides specialized control of vascular tone in a brainstem respiratory center in a manner that contributes to respiratory behavior.
https://elifesciences.org/articles/25232
Figures and data in Purinergic regulation of vascular tone in the retrotrapezoid nucleus is specialized to support the drive to...Figures and data in Purinergic regulation of vascular tone in the retrotrapezoid nucleus is specialized to support the drive to...
CO2/H+-dependent purinergic signaling by astrocytes provides specialized control of vascular tone in a brainstem respiratory center in a manner that contributes to respiratory behavior.
https://elifesciences.org/articles/25232/figures
How To Activate Medulla Oblongata
how to activate medulla oblongata Review of the functional areas of the brain part 1 by professor fink Central chemoreceptors respiratory system physiology nclex rn khan academy Midbrain, simplified sections of internal structure Baroreflex regulation of blood pressure, animation.
http://www.motupatlu.biz/how-to-activate-medulla-oblongata
Items where Subject is organism description | animal behavior | chemosensation - CSHL Scientific Digital RepositoryItems where Subject is organism description | animal behavior | chemosensation - CSHL Scientific Digital Repository
Bargmann, C., Callaway, E., Chklovskii, D. (2010) NEURONAL CIRCUITS. In: 2010 Meeting of Neuronal Circuits, March 10-March 13, 2010, Cold Spring Harbor Laboratory. ...
http://repository.cshl.edu/view/subjects/chemosensation.html
PPT - Chapter 22. PowerPoint Presentation - ID:163870PPT - Chapter 22. PowerPoint Presentation - ID:163870
Chapter 22. Respiratory System. Overview. Respiratory anatomy Respiration Respiratory musculature Ventilation, lung volumes and capacities Gas exchange and transport O 2 CO 2 Respiratory centers Chemoreceptor reflexes Respiratory Diseases. Oxygen. Slideshow 163870 by benjamin
https://www.slideserve.com/benjamin/chapter-22
3.1.1 The senses of chemoreception - Peking University | Coursera3.1.1 The senses of chemoreception - Peking University | Coursera
Video created by Peking University for the course Advanced Neurobiology II. 2000+ courses from schools like Stanford and Yale - no application required. Build career skills in data science, computer science, business, and more.
https://www.coursera.org/learn/advancedneurobiologyii/lecture/6p1Gs/3-1-1-the-senses-of-chemoreception
gilbertsonlaboratorygilbertsonlaboratory
a research laboratory at UCF College of Medicine in Lake Nona, FL devoted to the basic cellular, molecular and behavioral analyses of nutrient chemoreception
https://sites.google.com/site/gilbertsonlaboratory/home

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