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 ...
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 ...
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 ...
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 …
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.
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...
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 ...
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 ...
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?
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
Chemoreceptors are specialized nerve cells designed to respond to chemical stimuli. There are two types of chemoreceptors in the...
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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 ...
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).
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 ...
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 ...
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 ...
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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 ...
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. ...
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 ...
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 ...
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 ...
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 ...
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
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][18] These chemoreceptors are sensitive to the pH and levels of carbon dioxide in the cerebrospinal fluid.[12][10][18] (The peripheral chemoreceptors are located in the aortic bodies and carotid bodies adjacent to the arch of the aorta and to the ...
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 ...
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
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 ...
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 ...
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 ...
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 ...
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. ...
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 ...
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. ...
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 ...
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 ...
Soluble proteins containing 4 conserved cysteines which abundantly exist in the chemoreceptive organs and transmit chemical signals to nervous system . The CSP
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
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
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...
An increase in the internal diameter of an artery, triggered by vasomotor suppression, during the chemoreceptor response to decreased blood pressure.
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.
... 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.
Bargmann, C., Callaway, E., Chklovskii, D. (2010) NEURONAL CIRCUITS. In: 2010 Meeting of Neuronal Circuits, March 10-March 13, 2010, Cold Spring Harbor Laboratory. ...
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
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a research laboratory at UCF College of Medicine in Lake Nona, FL devoted to the basic cellular, molecular and behavioral analyses of nutrient chemoreception
The mechanism of oxygen sensing in arterial chemoreceptors is unknown but has often been linked to mitochondrial function. A common criticism of this hypothesis is that mitochondrial function is insensitive to physiological levels of hypoxia. Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type-1 cells. The oxygen sensitivity of mitochondrial [NADH] was assessed by monitoring autofluorescence and increased in hypoxia with a P50 of 15 mm Hg (1 mm Hg = 133.3 Pa) in normal Tyrode or 46 mm Hg in Ca(2+)-free Tyrode. Hypoxia also depolarised mitochondrial membrane potential (m, measured using rhodamine 123) with a P50 of 3.1, 3.3 and 2.8 mm Hg in normal Tyrode, Ca(2+)-free Tyrode and Tyrode containing the Ca(2+) channel antagonist Ni(2+), respectively. In the presence of oligomycin and low carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP; 75 nm) m is maintained by electron transport working against an artificial proton leak. Under these