Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

SK&F 101926 is a synthetic octapeptide which was designed to promote free water excretion by antagonizing the action of antidiuretic hormone. The clinical and pathologic changes in rats resulting from lethal doses of SK&F 101926 have suggested that death is associated with respiratory failure and/or cardiovascular collapse. To define the relationships between respiratory failure, cardiovascular collapse, and death, respiratory and cardiovascular parameters were monitored in anesthetized rats following the intravenous administration of SK&F 101926 at a dosage (3 mg/kg) which resulted in 70% mortality. Within 5 min after receiving this dosage, mean arterial blood pressure was reduced to values between 30 and 40 mm Hg in all rats. This degree of hypotension was well tolerated by some rats and, consequently, was not considered to be the cause of death. Deaths occurred between 9 and 58 min after dosing and were preceded by respiratory depression involving marked reductions in respiratory rate and the lack of compensatory increases in tidal volume. At the time of respiratory arrest, heart rates remained above 200 beats/min, mean arterial blood pressure remained between 30 and 40 mm Hg, and there were no consistent changes in dynamic lung compliance or total pulmonary resistance. Pretreatment of rats with a mast cell stabilizing agent (disodium cromoglycate), a mast cell degranulating agent (compound 48/80), or a histamine/5-hydroxytryptamine blocking agent (cyproheptadine) prevented the reductions in respiratory rate and death caused by SK&F 101926. These pretreatments also reduced the effect of SK&F 101926 on blood pressure, but were not able to completely prevent the hypotension.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Respiratory and cardiovascular changes associated with toxic doses of a peptide antagonist of vasopressin in the rat. 160 Dec 32

The present work was undertaken to elucidate the role of the vascular endothelium in the changes of isometric tension elicited by different compounds in isolated cylinders of human and cat cerebral arteries and cat pulmonary arteries. Endothelium removal by rubbing significantly reduced the relaxing response to acetylcholine (ACh) of isolated segments of all the arteries. The same treatment did not modify the contraction elicited by 5-hydroxytryptamine (5-HT) in the human and cat cerebral segments but increased the contractile effect of the amine in cat pulmonary arteries. The mechanical responses to vasopressin, ATP and adenosine in isolated segments of cat cerebral arteries were unaffected after removing the endothelial layer. L-Arginine, but not D-arginine (10(-5) M), enhanced significantly the relaxation induced by increasing doses of ACh in unrubbed cat cerebral arteries whereas it did not modify the response to ACh in rubbed ones. However, L-arginine had no effect on the dose-response curve to 5-HT in both kinds of preparation and did not change the tone in precontracted unrubbed cat cerebral segments. These results suggest that the endothelium of the cerebrovascular bed plays a minor role in regulating the mechanical response induced by several vasoactive agents, although it retains its ability to produce an endothelium-derived relaxing factor.
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PMID:Different influence of endothelium in the mechanical responses of human and cat isolated cerebral arteries to several agents. 167 38

The effect of endothelin-1 (ET-1) on vasoconstrictor responses of the endothelium-denuded perfused rabbit ear artery to 5-hydroxytryptamine (5-HT), histamine, and vasopressin (VP) was studied. In low concentrations with no vasoconstrictor action (0.1 and 0.3 nM), and in a concentration that increased the perfusion pressure by 70 mm Hg (1 nM), ET-1 significantly enhanced responses to the agonists studied; this enhancement was apparently mediated by an increased influx of extracellular calcium through voltage-operated channels, as it was abolished by the calcium channel antagonist nicardipine (10 nM). In contrast, higher concentrations of ET-1 (3 and 10 nM) inhibited responses to VP and 5-HT and this inhibitory effect was accentuated in the presence of nicardipine. The possible mechanism by which ET-1 exerts this inhibitory effect on vasoconstrictor responses is discussed. Because ET-1 is released from endothelial cells that are immediately adjacent to vascular smooth muscle cells, these modulatory effects of ET-1 on responses to endogenously present vasoconstrictors may play a role in vascular function.
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PMID:Effect of endothelin-1 on responses of isolated blood vessels to vasoconstrictor agonists. 172 43

The effects of Eschericia coli endotoxin on vascular responsiveness were compared with those of sodium nitroprusside in pithed rats. Infusion of endotoxin (250 micrograms kg-1 h-1) produced a fall in mean arterial blood pressure (11 mmHg) and impaired vasodepressor responses to endothelin, 5-hydroxytryptamine, acetylcholine, bradykinin, sodium nitroprusside and salbutamol. Prevention of endotoxin-induced hypotension with vasopressin infusion (0.64 i.u. kg-1 h-1 i.v.) restored responsiveness to bradykinin, tended to restore responsiveness to endothelin and sodium nitroprusside but failed to restore responsiveness to acetylcholine, 5-HT or salbutamol. Infusion of sodium nitroprusside at a rate (400 micrograms kg-1 h-1) producing a similar fall in blood pressure to that produced by endotoxin markedly impaired vasodepressor responsiveness to 5-HT. However, this was fully restored when the hypotension was prevented by vasopressin infusion. Vasodepressor responsiveness to either acetylcholine or salbutamol was not impaired by sodium nitroprusside in vasopressin-infused rats. The impairment of vasodepressor responsiveness by endotoxin is not due to endotoxin-induced hypotension and does not fit clearly with an endotoxin-mediated impairment of endothelial function.
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PMID:Endotoxin-induced impairment of vasodepressor responses in the pithed rat. 180 63

The effect of ischemia-reperfusion on endothelium-dependent relaxations and reactivity of vascular smooth-muscle cells was studied in rings of basilar arteries obtained from six dogs exposed to 12 min of complete global cerebral ischemia followed by 100 min of reperfusion. Three sham-operated control dogs served as controls. Ischemia was induced either by an increase in intracranial pressure or by aortic occlusion. The rings were suspended for isometric tension recording in physiological salt solution. Ischemia-reperfusion did not affect endothelium-dependent relaxations to vasopressin and bradykinin. In rings without endothelium relaxations to sodium nitroprusside, molsidomine (SIN-1), and papaverine as well as contractions to 5-hydroxytryptamine and KCl were preserved. These results demonstrate that in large canine cerebral arteries, ischemia-reperfusion of these durations does not affect relaxations mediated by activation of endothelium or direct relaxations and contractions of vascular smooth-muscle cells.
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PMID:Ischemia-reperfusion does not affect reactivity of isolated canine basilar artery. 187 14

In individuals above 60 years of age, an age-related decrease in the concentrations of dopamine, noradrenaline, and 5-hydroxytryptamine has been found. This may indicate a neuron loss. As the metabolites are not simultaneously reduced, a compensatory mechanism would seem to exist. In the hypothalamus there are significant positive correlations between the neuropeptides galanin and corticotropin-releasing factor on the one hand, and age over 60 on the other. In brains from patients with dementia of Alzheimer type there are reduced concentrations of cholineacetyl transferase. However, in some brain areas reduced concentrations of 5-hydroxytryptamine, dopamine, and noradrenaline have also been found. The metabolites homovanillic acid and 5-hydroxyindolacetic acid are also reduced. These findings indicate that there is not only a neuron loss in these brains but also a dysfunction of the remaining neurons, reducing the compensatory capacity of the brain. Postmortem investigations of hypothalamus from Alzheimer brains have shown reduced concentrations of 5-hydroxytryptamine. However, the concentrations of galanin, arginin, vasopressin, and somatostatin were significantly increased. The latter may be the result of a disturbed higher control over the hypothalamus. Hypothalamic dysfunction is of interest with regard to the neuroendocrine disturbances seen in Alzheimer-demented patients. Investigations of patients with vascular dementia have suggested the same type of neurotransmitter disturbances as in Alzheimer's disease.
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PMID:Biochemical substrates in normal aging and Alzheimer's disease. 197 Aug 89

1. Effects of atrial natriuretic peptide (ANP) on tension development, particulate guanylate cyclase activity and guanosine 3':5'-cyclic monophosphate (cyclic GMP) concentrations of uteri from oestrogen-treated, progesterone-treated, ovariectomized and pregnant rats were determined in vitro. 2. ANP inhibited the tension development by myometrial tissues from oestrogen-treated virgin rats and the sterile horn of 10 to 14 day pregnant rats but not of the uterus from pregnant and progesterone-treated rats. 3. Inhibition of cyclo-oxygenase and lipoxygenase activities did not restore the tocolytic activity of ANP on gravid uterus. ANP exerted a tocolytic effect on nongravid uterus submaximally stimulated by prostaglandin F2 alpha (PGF2 alpha), oxytocin, vasopressin, angiotensin II or 5-hydroxytryptamine (5-HT). 4. Ovariectomy decreased the tocolytic effects of ANP, which could be restored by oestrogen treatment. 5. The refractoriness to the tocolytic effect of ANP in pregnant rats was not accompanied by a decrease in its relaxant effects on isolated aortic strips. 6. Tocolytic effects of isoprenaline, isobutylmethyl xanthine and hydroxylamine were not influenced by pregnancy or progesterone treatment. Up to a concentration of 3 mM, sodium nitroprusside did not affect myometrial tension development. 7. Pregnancy and progesterone treatment markedly inhibited ANP-induced increases in myometrial particulate guanylate cyclase activity and cyclic GMP concentrations but did not influence the effects of ANP on aortic cyclic GMP concentrations. 8. It is concluded that exposure of the myometrium to circulating and placentally-produced progesterone is responsible for the pregnancy-induced decrease in the effects of ANP on myometrial particulate guanylate cyclase activity and cyclic GMP concentrations and in turn on myometrial tension development.
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PMID:Refractoriness of the gravid rat uterus to tocolytic and biochemical effects of atrial natriuretic peptide. 197 61

1. Effects of vasoactive substances were investigated in the canine isolated spinal branch of the intercostal artery (SBICA). 2. Addition of angiotensin II (AII), vasopressin, noradrenaline (NA), adrenaline, 5-hydroxytryptamine (5-HT), and dopamine each produced concentration-dependent contraction in the SBICA, whereas prostaglandin F2 alpha, histamine, and tyramine caused only slight contraction. The decreasing order of the potency of contractile agents was AII much greater than vasopressin = NA greater than 5-HT greater than adrenaline much greater than dopamine. 3. Although the pD2 value for phenylephrine (5.31 +/- 0.36) was smaller than that for NA (6.48 +/- 0.13), there was no significant difference in Emax value between these two agonists in the SBICA. On the other hand, xylazine produced only a slight contraction, the pD2 value being 3.59 +/- 0.08. Phentolamine (10(-8)-10(-6) M) and prazosin (10(-8)-10(-6) M) competitively inhibited the NA-induced contraction, while yohimbine (10(-8)-10(-6) M) did not. 4. Acetylcholine (ACh), sodium nitroprusside (SNP), ATP, ADP, and adenosine caused concentration-dependent relaxations in SBICA following contraction with NA. On the other hand, isoprenaline up to 10(-4) M did not produce any relaxation. The decreasing order of potency of the relaxant agents was ACh greater than SNP much greater than ATP = ADP = adenosine. 5. The ACh-induced relaxation was competitively inhibited by atropine and was abolished by mechanical removal of the endothelium. Aspirin (5 x 10(-5) M) did not affect the relaxant response to ACh, while oxyhaemoglobin (10(-5) M) and methylene blue (10(-5) M) produced significant attenuation. 6. These results suggest that NA produces contraction of the isolated canine SBICA which is mainly mediated via alpha 1-adrenoceptors and that ACh causes a relaxation of the SBICA due to release of endothelium-derived relaxing factor (EDRF) from the endothelial cells.
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PMID:Contractile and relaxant responses of the canine isolated spinal artery to vasoactive substances. 198 Aug 36

In addition to the classical transmitters noradrenaline and acetylcholine, other transmitters have been identified in perivascular nerves, including 5-hydroxytryptamine, ATP and a number of peptides. This paper discusses pre- and postjunctional neuromodulation of vascular transmission, and cotransmission involving noradrenaline, ATP and neuropeptide Y in sympathetic nerves, acetylcholine and vasoactive intestinal polypeptide in parasympathetic nerves, and substance P, calcitonin gene-related peptide and ATP in 'sensory-motor' nerves. Vasomotor nerves derived from intrinsic neurones, for example in the heart and gut, are also discussed. Subpopulations of endothelial cells store and release a variety of substances, including acetylcholine, substance P, ATP, 5-hydroxytryptamine, vasopressin and angiotensin II, that act on receptors on endothelial cells and lead to the production of endothelium-derived relaxing factor (identified as nitric oxide) which, in turn, produces vasodilation in response to changes in flow and hypoxia. Endothelium-derived contracting factors such as endothelin may also be released. There appears to be a resting dynamic balance between endothelium-derived vasodilator tone and sympathetic vasoconstrictor tone, which is altered under different physiological and pathophysiological circumstances. Long-term (trophic) interactions between perivascular nerves and endothelial cells are discussed, as are the changes in vascular control mechanisms that occur with ageing and hypertension and in the nerves that remain following trauma or surgery.
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PMID:Local mechanisms of blood flow control by perivascular nerves and endothelium. 198 71

Vasoconstriction by norepinephrine, angiotensin II and vasopressin in the constant-flow perfused rat hindlimb is associated with increased oxygen uptake and has given rise to the concept of vascular thermogenesis. In the present study serotonin (5-hydroxytryptamine, 5HT) was found to inhibit oxygen uptake by up to 40% in a dose dependent manner whilst inducing vasoconstriction in this model, whereas norepinephrine increased oxygen consumption by up to 100% during vasoconstriction. This contrasted with the perfused isolated rat mesenteric artery arcade in which serotonin stimulated oxygen uptake by up to 130% in association with vasoconstriction in a dose dependent manner similar to the previously described norepinephrine induced vascular thermogenesis in this arterial preparation. In both perfusion systems, changes in pressure and oxygen uptake mediated by serotonin were completely blocked by ketanserin. These results and evidence from dye washout studies suggest that serotonin-mediated vascular thermogenesis, if it occurs in the constant-flow hindlimb, is masked by vascular shunting.
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PMID:The apparent absence of serotonin-mediated vascular thermogenesis in perfused rat hindlimb may result from vascular shunting. 201 89


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