Sleep apnea (SA) affects as many as 20% of the adult population in the United States. It elicits intermittent hypoxia (IH) and causes pulmonary hypertension (PH), however the mechanisms of this PH have not been well studied. IH has been shown to cause polycythemia, pulmonary vascular remodeling and increases in vasoconstrictor reactivity. CO2 supplementation may be protective in the development of PH, therefore we assessed effects of IH with and without CO2 supplementation on indices of PH and pulmonary vasoconstrictor reactivity. IH with CO2 supplementation resulted in eucapnic IH (E-IH) and the lack of polycythemia or vascular remodeling. However, E-IH caused significant right ventricular hypertrophy and increased pulmonary vasoconstrictor reactivity, which was mediated by vascular smooth muscle (VSM) Ca2+ sensitization. We, therefore, sought to determine the mechanism of this enhanced vasoconstrictor reactivity by assessing vasoconstriction and VSM Ca2+ responses to the endothelium-derived
TY - JOUR. T1 - Effects of S-nitrosation and cross-linking of hemoglobin on hypoxic pulmonary vasoconstriction in isolated rat lungs. AU - Deem, Steven. AU - Kim, Joung Uk. AU - Manjula, Belur N.. AU - Acharya, A. Seetharama. AU - Kerr, Mark E.. AU - Patel, Rakesh P.. AU - Gladwin, Mark T.. AU - Swenson, Erik R.. PY - 2002/10/4. Y1 - 2002/10/4. N2 - Free hemoglobin (Hb) and red blood cells augment hypoxic pulmonary vasoconstriction (HPV) by scavenging nitric oxide (NO). S-nitrosation of Hb (SNO-Hb) may confer vasodilatory properties by allowing release of NO during deoxygenation and/or by interaction with small-molecular weight thiols. Likewise, cross-linking of free Hb may limit its vasoconstrictive effect by preventing abluminal movement of the molecule. We compared the effects of free SNO-Hb and Hb intramolecularly cross-linked at the β-cysteine 93 residue [Bis(maleidophenyl)-polyethylene glycol2000HbA (Bis-Mal-PEGHb)] to those of free oxyHb on pulmonary artery pressure (PAP), HPV, and ...
In isolated blood-perfused rat lungs, brief periods of ventilation hypoxia (2% O2) produce pulmonary vasoconstriction. In isolated lungs perfused with a salt-albumin solution, hypoxia produces no pulmonary vasoconstrictor responses in most preparations and only minimal responses in others. Vasoactive agents including angiotensin II, phenylephrine, epinephrine, norepinephrine, bradykinin, histamine, serotonin, and methoxamine were added to the salt-albumin perfusate to determine which substance, if any, was necessary for a pulmonary vasoconstrictor response during hypoxia. The addition of angiotensin II (12-120 nM) to the perfusate during hypoxia resulted in marked pulmonary vasoconstriction in proportion to the amount of angiotensin II added (a maximal response to hypoxia occurred with 120 nM angiotensin II). None of the other agents had the same effect, nor was their vasoactivity dependent on angiotensin II. Angiotensin II augmented the hypoxic response in doses that are themselves subpressor; ...
BACKGROUND: Hypoxic pulmonary vasoconstriction (HPV) is a defense mechanism to maintain adequate oxygenation. It has been reported that metabolism inhibition augments HPV. The purpose of the present study was, therefore, to determine the effect of metabolism inhibition on HPV in a rabbit model of isolated lung perfusion with exclusion of the influential factors on HPV. METHODS: In adult rabbits, lungs were isolated and perfused with a constant pulmonary perfusate flow. Acid-base status and temperature of perfusate was also constantly maintained. Thirty minutes after, the baseline hypoxic pressor response (HPR) was measured as the difference of pulmonary artery pressure (PAP) between a period of 21% normoxic gas inhalation and that of 3% hypoxic gas inhalation. After another thirty minutes, 2-deoxy-D-glucose 100 mg was mixed with the perfusate, and then HPR was measured three times. After checking metabolism inhibition effects, D-glucose 300 mg was mixed to the perfusate to reverse metabolism ...
TY - JOUR. T1 - Gender differences in the effect of age on electrical field stimulation (EFS)-induced adrenergic vasoconstriction in rat mesenteric resistance arteries. AU - Sullivan, Jennifer C. AU - Davison, Cathy A.. PY - 2001/3/14. Y1 - 2001/3/14. N2 - The objective of this study was to examine the effects of gender and age on electrical field stimulation (EFS)-induced vasoconstriction. Fisher 344 rats were studied: young females (YF, n = 38), young males (YM, n = 29), old females (OF, n = 33), and old males (OM, n = 30). Isolated mesenteric resistance arteries (endothelium-intact or denuded) were pressurized, and outer diameter was monitored. Dose-response curves were performed to KCl and phenylephrine (PE). EFS (0.1-16 Hz) responses were expressed as percentage of constriction from baseline. Area under the curve (AUC) was calculated and comparisons were made using analysis of variance and t tests. Females became less responsive to EFS-induced constriction with age, whereas constrictor ...
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We investigated the possible contributions of reactive oxygen species and of viscosity changes to hemodilution-induced inhibition of hypoxic pulmonary vasoconstriction (HPV) in dogs. Fourteen isoflurane-anesthetized dogs were randomly assigned to receive N-acetylcysteine (NAC) 200 mg/kg IV (n = 7) or placebo (n = 7). Mean pulmonary artery pressure (Ppa) was measured with cardiac output maintained constant by a manipulation of venous return in hyperoxia (fraction of inspired oxygen, 0.4) and in hypoxia (fraction of inspired oxygen, 0.1) at baseline and after stepwise reductions in hematocrit from 40% to 20%. Measured Ppa was compared with predicted Ppa by using a viscoelastic model. HPV was expressed as hypoxic Ppa minus hyperoxic Ppa. Hemodilution was associated with a decrease in HPV from 7 ± 1 mm Hg to 3 ± 1 mm Hg (P , 0.01), and this was completely prevented by NAC (HPV was unchanged, from 8 ± 1 to 8 ± 1 mm Hg; not significant). Hemodilution in the model decreased HPV from 8 ± 1 mm Hg to ...
Studies performed in our laboratory in conscious animals, demonstrate that the responsiveness of α-adrenergic receptors on the arterial vasculature of skeletal muscle is reduced during dynamic exercise compared to rest. A classical view of sympathetic vasoconstriction describes the release of norepinephrine (NE) which binds postsynaptic α-adrenergic receptors. There are two distinct populations of α-adrenergic receptors (α1 and α2) found of vascular smooth muscle, both of which produce vasoconstriction when stimulated. We have shown an attenuation of vasoconstriction during exercise with simultaneous stimulation of both populations of receptors. When examining the contribution of α1 and α2 receptors individually, α2 receptors appear to be much more sensitive to attenuation by exercise than α1 receptors. Existing evidence suggests that ATP acts as a neurotransmitter in vascular smooth muscle and is co-released with norepinephrine from sympathetic nerves. Recently we have examined P2X ...
Synonyms for vasoconstriction in Free Thesaurus. Antonyms for vasoconstriction. 1 word related to vasoconstriction: constriction. What are synonyms for vasoconstriction?
The results of the present study demonstrate that 20-HETE is produced by rat cerebral microvessels, and immunoreactive protein and mRNA for P-450 4A1, 4A2, 4A3, and 4A8 isoforms are expressed in these vessels. Subsequent GC/MS analysis confirmed the presence of 20-HETE in cerebral arteries and that an elevation in the transmural pressure from 20 to 140 mm Hg increased 20-HETE concentration in these vessels by 6-fold. The rise in 20-HETE concentration with elevation in transmural pressure suggests a role for this endogenous vasoconstrictor in the generation of pressure-induced cerebral vasoconstriction. Our findings that inhibitors of the formation of 20-HETE or blockers of its vasoconstrictor action eliminate the pressure-induced constriction of isolated cerebral arteries indicate that endogenous 20-HETE is an important component of pressure-induced cerebral arterial constriction. The idea that 20-HETE plays an important role in autoregulation of CBF is further supported by the observation that ...
Definition of vasoconstriction in the Definitions.net dictionary. Meaning of vasoconstriction. What does vasoconstriction mean? Information and translations of vasoconstriction in the most comprehensive dictionary definitions resource on the web.
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TY - JOUR. T1 - Angiotensin II stimulates internalization and degradation of arterial myocyte plasma membrane BK channels to induce vasoconstriction. AU - Leo, Marie Dennis. AU - Bulley, Simon. AU - Bannister, John P.. AU - Pushpamangalam Kuruvilla, Korah. AU - Narayanan, Damodaran. AU - Jaggar, Jonathan. PY - 2015/9/15. Y1 - 2015/9/15. N2 - Arterial smooth muscle cells (myocytes) express large-conductance Ca2+- activated K+ (BK) channel α and auxiliary β1 subunits that modulate arterial contractility. In arterial myocytes, β1 subunits are stored within highly mobile rab11A-positive recycling endosomes. In contrast, BKα subunits are primarily plasma membrane-localized. Trafficking pathways for BKα and whether physiological stimuli that regulate arterial contractility alter BKα localization in arterial myocytes are unclear. Here, using biotinylation, immunofluorescence resonance energy transfer (immunoFRET) microscopy, and RNAimediated knockdown, we demonstrate that rab4A-positive early ...
There does not need to be a change in circulating blood volume during exercise; the role of vasoconstriction is more subtle than that.. Vasoconstriction increases the stiffness of venous vessels leading back to the heart. This makes them act more like stiff tubes than elastic reservoirs. As a result, any extra blood pumped by the heart is more likely to return to the heart rather than to be stored in the venous vasculature. The importance of regulating venous return in concert with cardiac function has been appreciated at least since the work of Guyton and colleagues in the 1950s.. In exercise the effective muscle pump arising from the combination of muscle contraction and valves in the veins preventing backflow is also important; both the muscle pump and venoconstriction promote venous return to the heart.. ...
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Lipodema is a chronic disease of complex causes, many of which we understand little about. These include hormonal imbalance, an inability to metabolise exudate from blood vessels so that those proteins and cells that would normally be metabolised and returned to the circulation are deposited as adipose tissue in the subcutaneous tissue. The blood vessels themselves are affected, venous stasis and vasoconstriction occur and return is diminished especially at the subcutaneous level. This causes arterial constriction which accounts for the cold and often pale skin and leads to an increased lymphatic load(1). The condition worsens over years as tissue channels become progressively narrowed until the condition of a secondary lymphoedema, overlying the original lipodema, may lead to a situation where the patient may be either wheel-chair bound or bedridden. Weight gains can be up to or greater than 250 kgs. At this stage infections and intractable ulcers (or ones that necessitate skin grafts when lack ...
Zhou Z, Hemradj V, de Beer VJ, Gao F, Hoekstra M, Merkus D, Duncker DJ. Cytochrome P-450 2C9 exerts a vasoconstrictor influence… Expand ...
In the early hours of the morning, near the end of the shift, I received a call to a 19 year-old male who was having an allergic reaction to his medicine. I arrived to find the man shivering in a chair and looking unwell. His friends were with him and they told me that he had brought medicine for a cold back from India where he had been recently and that he had started reacting to it. He had an erythemic rash but his airway seemed safe. His BP was a concern, however; it was consistently low - sometimes very low. When the crew arrived and we got him into the ambulance, we pondered this situation some more and I noticed that his feet were a little swollen and very red. I considered the possibility that the reaction was causing fluid pooling in his peripheries, which would explain his low BP. His legs were raised but this didnt help much, so I set up fluids and asked the crew to give him adrenaline, which would reverse the effects of histamine and nitric oxide and cause vasoconstriction, which in ...
Endothelial dysfunction plays a major role in ischemic cardiovascular disease, hypertension and cerebrovascular disease. Endothelium (inner lining of blood vessels) produces chemicals which result in relaxation of blood vessel muscles so the blood vessels can dilate. Also, produced are chemicals which cause the blood vessels to constrict. An imbalance in this dilation and constriction can […]. View Post ...
TY - JOUR. T1 - Characterization of the inhibitory effect of vascular endothelium on agonist-induced vasoconstriction in rat mesenteric resistance arteries. AU - Jin, Xin. AU - Satoh-Otonashi, Yukiko. AU - Zamami, Yoshito. AU - Koyama, Toshihiro. AU - Sun, Pengyuan. AU - Kitamura, Yoshihisa. AU - Kawasaki, Hiromu. PY - 2008. Y1 - 2008. N2 - Vascular endothelium regulates vascular tone by releasing endothelium-derived vasoactive substances. We performed this study to characterize the inhibitory effect of the endothelium on vasoconstrictor stimuli in rat mesenteric vascular beds. Changes in perfusion pressure induced by continuous perfusion of Krebs solution containing methoxamine (α1-adrenoceptor agonist) or high KCl were measured over 180 min. In preparations with intact endothelium, methoxamine-induced vasoconstriction was time-dependently decreased to cause 60% - 80% reduction of the initial vasoconstriction level, while no reduction was observed in high-KCl-induced vasoconstriction. ...
To determine whether balloon angioplasty can provoke arterial vasoconstriction independent of platelet aggregation and neurogenic input, we studied the spontaneous vasomotor effects of balloon dilatation in isolated, perfused whole-vessel segments of rabbit aorta and pig carotid artery. Freshly dissected rabbit thoracic aortas were mounted in a muscle bath-perfusion chamber, perfused with physiologic saline solution at 70 mm Hg, and allowed to equilibrate. The proximal or distal half of the aortas were dilated with either a "large" (5 mm, 31-51% stretch beyond relaxed diameter) or a "small" (4 mm, 5-16% stretch) balloon angioplasty catheter with the other half of the vessel serving as the control. A similar series of experiments were performed in pig carotid arteries using "large" (6 or 8 mm, 48-90% stretch) balloon catheters. The spontaneous vasomotor effects of balloon angioplasty were examined with long-axis, high-frequency ultrasonic imaging combined with computerized edge detection image ...
TY - JOUR. T1 - Endothelin B receptor deficiency potentiates ET-1 and hypoxic pulmonary vasoconstriction. AU - Ivy, D. Dunbar. AU - Mcmurtry, Ivan F.. AU - Yanagisawa, Masashi. AU - Gariepy, Cheryl E.. AU - Le Cras, Timothy D.. AU - Gebb, Sarah A.. AU - Morris, Kenneth G.. AU - Wiseman, Richard C.. AU - Abman, Steven H.. PY - 2001/5. Y1 - 2001/5. N2 - Endothelin (ET)-1 contributes to the regulation of pulmonary vascular tone by stimulation of the ETA and ETB receptors. Although activation of the ETA receptor causes vasoconstriction, stimulation of the ETB receptors can elicit either vasodilation or vasoconstriction. To examine the physiological role of the ETB receptor in the pulmonary circulation, we studied a genetic rat model of ETB receptor deficiency [transgenic(sl/sl)]. We hypothesized that deficiency of the ETB receptor would predispose the transgenic(sl/sl) rat lung circulation to enhanced pulmonary vasoconstriction. We found that the lungs of transgenic(sl/sl) rats are ETB deficient ...
... was originally described in 1946, by Von Euler and Liljestrand - they were studying the effects of hypoxic gas mixtures, and found that PA pressures increased with 10.5% inspired O2 [Von Euler and Liljestrand. Acta Physiol Scand 12: 301, 1946]. Since then, HPV has been well-described in multiple mammalian models, including humans. It is thought to result from a pathway involving NO and/or COOX inhibition [Moudgil R et al. J Appl Physiol 98: 390, 2005]. HPV takes effect over 30 minutes, although peak effect takes up to two hours. Interestingly, HPV sensitization occurs, in which a second incidence of hypoxemia produces a more significant response than the first [Dorrington KL et al. Am J Physiol Heart Circ Physiol 273, H1126, 1997] In addition to PAO2, HPV is dependent on both PaO2 and PvO2, although in the atelectatic lung only PvO2 matters and overall PAO2 is by far most important. Of note, HPV functions best when 30-70% of the lung is hypoxic - if , 30% of ...
Homocysteinemia is a major and independent risk factor for vascular disease. Oxidative stress is a possible mechanism for homocysteine (HCY)-induced vascular disease. Herein, we evaluated the antioxidant property of melatonin (MLT) in relation to the vasoconstrictive effect of HCY on the human umbilical artery. Helical umbilical arterial strips without endothelium were obtained at elective Cesarean delivery near term. Changes in potassium chloride (KCl)-induced vasoconstriction were measured. Arterial strips were treated with HCY (10 or 100 microM) plus FeSO(4) (10 microM) alone or pretreated with a hydroxyl radical ((*)OH) scavenger, mannitol (20 mM), or MLT (1 or 10 microM). The effect of HCY on the response of arterial strips to external calcium (Ca(2+)) in the presence of KCl (20 mM) was determined. HCY plus FeSO(4) potentiated KCl-induced vasoconstriction in a concentration-dependent manner; pretreatment with mannitol significantly reduced this vasospastic effect. HCY (100 microM) significantly
TRPV4 channel contributes to serotonin-induced pulmonary vasoconstriction and the enhanced vascular reactivity in chronic hypoxic pulmonary hypertension.
The primary autonomic effects of amphetamines are on the vasculature and heart. Activation of alpha1 receptors can lead to significant vasoconstriction while at higher doses activation of beta1 receptors can increased heart rate and contractility. Together these effects can yield prominent systolic and diastolic hypertension. At toxic doses individuals may feel palpitations that can ultimately evolve into frank arrhythmias ...
It has repeatedly been shown that angiotensin II pretreatment enhances the subsequent hypoxic pressor responses in preparations perfused with artificial
Responses to angiotensin II were also depressed in adrenalectomized rats (Figure 2). Bolus angiotensin injections in isolated lungs produced typical transient
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Parenchymal arterioles (PAs) are high-resistance vessels in the brain that connect pial vessels to the microcirculation. We previously showed that PAs have increased vasoconstriction after ischemia and reperfusion that could increase perfusion defici
The primary novel finding of the present study is that sympathetic vasoconstrictor tone of the lower limb (i.e., leg) is augmented in old compared with young women. Specifically, young women exhibit no detectable sympathetic vasoconstriction in their leg vasculature at rest. Conversely, there appears to be robust vasoconstriction in the resting lower limbs of older women. Collectively, these findings suggest that with advanced age there is an "emergence" of a sympathetic neural influence on leg vascular tone in women. These conclusions are based on the observation that acute sympathetic inhibition via carotid artery baroreceptor loading increased femoral artery vascular conductance (FVC; Fig. 1) ~21% in old women, whereas FVC was unchanged in the younger women with the same intervention.. It is well established that muscle sympathetic nerve activity (MSNA) is augmented with age in women (Ng et al. 1993; Matsukawa et al. 1998; Moreau et al. 2003; Narkiewicz et al. 2005; Hart et al. 2011; Barnes ...
Angiotensin II (Ang II) is one of the most potent vasoconstrictor substances, yet paradoxically. Ang II may dilate certain vascular beds via an undefined mechanism. Ang II-induced vasoconstriction is mediated by the AT1 receptor, whereas the relative expression and functional importance of the AT2 receptor in regulating vascular resistance and blood pressure are unknown. We now report that Ang II induces relaxation of mesenteric microvessels and that this vasodilatory response was unaffected by losartan, an AT1 receptor antagonist, but was inhibited by PD123.319. a selective antagonist of AT2 receptors. In addition, reverse transcriptase-polymerase chain reaction studies revealed high amounts of AT2 receptor mRNA in smooth muscle from these same microvessels. Ang II-induced relaxation was inhibited by either tetraethylammonium or iberiotoxin, suggesting involvement of the large-conductance, calcium- and voltage-activated potassium (BKCa) channel. Subsequent whole-cell and single-channel patch-clamp
Biology of Vascular Smooth Muscle: Vasoconstriction and Dilatation - ISBN: 9789811048104 - (ebook) - von Yuansheng Gao, Verlag: Springer
Cardiovascular dysfunction is usually a primary indie predictor of age-related morbidity and mortality. Strategies To be able to evaluate the function of IL-10 in maintenance of vascular function, power stress myography was useful to gain access to ex-vivo endothelium reliant vasorelaxation in vessels isolated from IL-10 knockout IL-10(tm/tm) and control mice. Pulse influx speed ((PWV), index of rigidity) of vasculature was assessed using ultrasound and blood circulation pressure was assessed using the tail cuff technique. Echocardiography was utilized to elucidated framework and functional adjustments in the center. Outcomes Mean arterial stresses were considerably higher in IL-10(tm/tm) mice when compared with C57BL6/outrageous type (WT) handles. PWV was elevated in IL-10(tm/tm) indicating stiffer vasculature. GMCSF Endothelial unchanged aortic bands isolated from IL-10(tm/tm) mice confirmed impaired vasodilation at low acetylcholine dosages and vasoconstriction at higher dosages whereas ...
Epinephrine acts on alpha receptors causing vasoconstriction and on beta receptors causing vasodilation. The affinity of epinephrine for beta receptors is somewhat greater than its affinity for alpha receptors. When given in low doses, or by slow IV infusion in humans, the beta effects of epinephrine may predominate. When given in a large IV bolus dose, as here, the alpha effects (vasoconstriction) predominate when the concentration of epinephrine is high, and the beta effects (vasodilation) may sometimes be seen as the concentration is falling. From these facts you may be able to infer the relative affinity of epinephrine for alpha receptors on the one hand, and beta receptors on the other hand.The fact that vasoconstriction predominates when both alpha and beta receptors are activated shows that the capacity for vasoconstriction mediated by alpha receptors is very great, whereas the capacity for vasodilation mediated by beta receptors is somewhat limited. ...
• Extensively used in plastic surgery to produce vasoconstriction, which reduces blood loss during surgery, although there is some concern
Results Acetylcholine induced significant vasoconstrictive responses in the distal but not in the proximal segments of both the stented (-11 ± 7% versus baseline; p , .01) and the contralateral vessels (-11 ± 6%; p , .01), which were significantly correlated (R = .48; p , .05) and were completely reverted by nitroglycerine. Inducible ischemia was the only predictive factor for distal vasoconstriction in the stented vessel (p , .01) but not in the contralateral vessel (p = .06). Patients with minor signs of ischemia at the ergometric test showed a greater vasoconstriction than those with a completely normal test (-16 ± 7% versus -7 ± 6%; p , .01). ...
The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS ...
The major findings of this study are that blockade of NOS with L‐NAME (but not with the iNOS inhibitor L‐canavanine) caused marked increases in the already elevated RVSP at 3, 5, and 8 weeks after the initiation of the SU/Hx/Nx‐induced PAH in rats that simulate the human PAH phenotype histologically as well as hemodynamically (Abe et al. 2010; Toba et al. 2014). The increases in RVSP in response to L‐NAME were apparently caused by active pulmonary vasoconstriction since they were not accompanied by increases in cardiac output. In contrast, NOS inhibition did not increase the elevated RVSP nor decrease the CI at an earlier time point (1 week after the initiation) of this PAH model. It has previously been shown that Rho kinase‐mediated vasoconstriction contributes markedly to the high RVSP and TPRI throughout the PAH process, that is, from the early (1‐week) to the late (13‐week time point) in SU/Hx/Nx rats (Oka et al. 2007; Toba et al. 2014). It is therefore speculated that at late ...
I had a heart attack in the beginning of October of this year (confirmed by elevated cardiac enzymes) and in the angiogram (sp) they did not find a blockage but were able to see where the damage was an...
Acetylcholine, Animal, Animal Model, Atherosclerosis, Cardiovascular Disease, Depression, Disease, Endothelium, Mice, Patients, Phenylephrine, Procedure, Risk, Risk Factor, Vasoconstriction, Vasorelaxation
Adults, Aging, Air, Elderly, Productivity, Sensation, Skin, Skin Temperature, Temperature, Transient, Vasoconstriction, Young Adults
TY - JOUR. T1 - Influence of prostaglandin F2α analogues on the secretory function of bovine luteal cells and ovarian arterial contractility in vitro. AU - Korzekwa, A. J.. AU - Lukasik, K.. AU - Pilawski, W.. AU - Piotrowska-Tomala, K. K.. AU - Jaroszewski, J. J.. AU - Yoshioka, S.. AU - Okuda, K.. AU - Skarzynski, D. J.. PY - 2014/1. Y1 - 2014/1. N2 - Although prostaglandin (PG) F2α analogues are routinely used for oestrus synchronisation in cattle, their effects on the function of the bovine corpus luteum (CL), and on ovarian arterial contractility, may not reflect the physiological effects of endogenous PGF2α. In the first of two related experiments, the effects of different analogues of PGF2α (aPGF2α) on the secretory function and apoptosis of cultured bovine cells of the CL were assessed. Enzymatically-isolated bovine luteal cells (from between days 8 and 12 of the oestrous cycle), were stimulated for 24h with naturally-occurring PGF2α or aPGF2α (dinoprost, cloprostenol or ...
The soluble epoxide hydrolase (sEH), which is expressed in pulmonary artery smooth muscle cells, metabolizes cytochrome P450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) to their less active diols. Preliminary findings indicate a role of the sEH on hypoxic pulmonary vasoconstriction (HPV) and a vasoconstrictor role of EETs in the pulmonary vasculature. Here we assessed the influence of hypoxia on the expression of the sEH, acute HPV and pulmonary vascular remodeling. In lungs from wild-type mice (WT), exposure to hypoxia (FiO2 = 0.1) for 21 days decreased the expression of the sEH by 70% (RT-PCR), and increased the number of partially and fully muscularised resistance arteries (by 3-fold). In isolated lungs, pre-exposure to chronic hypoxia significantly increased baseline perfusion pressures (1.3-fold) and potentiated the acute HPV (1.5-fold). While an sEH inhibitor (1-adamantyl-3-cyclohexylurea; ACU) potentiated acute HPV in lungs from mice maintained in normoxic conditions, it ...
1. To test whether almitrine might improve the arterial partial pressure of O2 in patients with chronic obstructive airways disease by improvement of ventilation-perfusion matching, we looked at the interaction between hypoxic and almitrine-induced vasoconstriction in isolated rat lungs perfused with blood at constant flow. Increases in pressure represented increases in resistance.. 2. Almitrine, given in increasing doses between challenges with 2% O2, enhanced hypoxic vasoconstriction at low doses but attenuated it at high doses.. 3. Stimulus-response curves to hypoxia of increasing severity gave a sigmoid curve.. 4. Almitrine solvent caused small changes in pulmonary artery pressure and shifted the stimulus-response curve slightly in a parallel fashion.. 5. Small doses of almitrine enhanced the action of mild to moderate hypoxia, medium doses attenuated moderately severe hypoxia, whereas high doses depressed vasoconstriction due to all degrees of hypoxia.. 6. These effects of almitrine on ...
TY - JOUR. T1 - Cerebral microvascular responses to endothelins. T2 - The role of ET(A) receptors. AU - Sagher, O.. AU - Jin, Y.. AU - Thai, Quoc-Anh. AU - Fergus, A.. AU - Kassell, N. F.. AU - Lee, K. S.. PY - 1994. Y1 - 1994. N2 - The regulatory role of endothelins in cerebral microvessels was investigated in a recently developed model system which allows the study of small cerebral vessels in their normal microenvironment. Using brain slices of the rat neocortex, it was shown that the isopeptide endothelin-3 (ET-3) had no effect on cerebral microvessels, while the isopeptide endothelin-1 (ET-1) produced a potent, dose-dependent vasoconstriction. When a recently developed antagonist of ET(A) receptors (Cyclo-[D-Asp-L-Pro-D-Val-L-Leu-D-Trp]; ETant) was administered prior to treatment with ET-1, the vasoconstrictor response to ET-l was inhibited in a dose-dependent manner. When ETant was administered after the establishment of a constriction by ET-l, the constrictor response to ET-1 was ...
Our previous studies suggested that enhanced pulmonary artery contractions to arachidonic acid in females compared with males were mediated by an LO metabolite.6 The purpose of the current study was to systematically characterize the LO pathways in female and male pulmonary arteries. First, it was shown that the protein expression of both 15- and 5-LO was greater in females compared with males. Although pulmonary arteries from both male and females produced the corresponding LO metabolites, 15- and 5-HETE, only the synthesis of 15-HETE was enhanced in females. The increase in 15-HETE was correlated with an increased 15-HETE-mediated pulmonary artery vasoconstriction in females compared with males. These findings are significant because it is the first report that the 15-LO pathway is regulated in a sex-specific way. These results may impact what is known about the sex differences in the incidence of PAH.. The enhanced vasoconstriction in females compared with males could be because of increased ...