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)

We investigated the effects of 17 beta-estradiol (beta E2), alpha-estradiol (alpha E2), and progesterone (P) on baseline and vasopressin (AVP)-induced [Ca2+]i in human platelets obtained from healthy male and female volunteers. Platelets were treated with beta E2, alpha E2, P, or ethanol vehicle for 30 min at 37 degrees C. In males, both beta E2 and P at 10(-5) mol/L reduced the AVP-induced rise in [Ca2+]i, to 72 +/- 3% (mean +/- SEM) and 53 +/- 3%, respectively. However, at 10(-6) mol/L only beta E2 had a significant effect (P < .02). In females, 10(-6) and 10(-5) beta E2 reduced the AVP response to 85.3 +/- 4.6% and 80.8 +/- 5.4% of control values, respectively. Progesterone (10(-6) and 10(-5) mol/L) reduced the AVP response to 83.8 +/- 5.1% and 60.3 +/- 2.0% of control values, respectively. The inactive estrogen alpha E2 had no effect on basal or AVP-induced rise in [Ca2+]i in either subject population, suggesting hormonal specificity. Neither beta E2 nor P affected baseline [Ca2+]i in either population. Thus, by attenuating [Ca2+]i responses in platelets, beta E2 and P may modulate platelet aggregation and atherosclerosis.
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PMID:Effects of estradiol and progesterone on platelet calcium responses. 775 50

Neuropeptide Y (NPY), a sympathetic and platelet-derived vasoconstrictor, acts both directly and by potentiating adrenergic responsiveness and therefore may be beneficial in endotoxic shock, where suppressed vascular responsiveness to adrenergic agents is a key factor. This was studied in anesthetized rats. First, infusion of a nonhypotensive dose of endotoxin (lipopolysaccharide, LPS) markedly suppressed the pressor response to increasing doses of norepinephrine (NE), angiotensin II, and vasopressin but did not suppress the response to NPY. Second, in rats rendered hypotensive by intravenous LPS, continuous NE infusion (0.1-1.0 microgram.kg-1 x min-1 started 5 min after LPS for 1 h) did not alter hemodynamics. In contrast, 5 nmol.kg-1 x min-1 of NPY (equipotent to 0.1 microgram.kg-1 x min-1 of NE in normal rats) increased mean arterial pressure (MAP, from 64 to 114% of baseline), total peripheral resistance index (TPRI, from 64 to 154% of baseline), and left ventricular stroke work index (from 36 to 73% of baseline), without changing cardiac index (CI). Third, in a similar experimental protocol, pretreatment of the hypotensive rats with phentolamine blocked the pressor effect of NE infusion, but only partially attenuated the response to NPY. Finally, addition of low-dose NPY to NE infusion improved survival following a lethal dose of LPS compared with treatment with NE alone (P < 0.01). Thus, unlike other vasoconstrictors tested, NPY-mediated vasoconstriction is preserved during endotoxemia. The beneficial effect of NPY is mediated by increased TPRI without reduction in CI; both NPY receptor-mediated vasoconstriction and potentiation of adrenergic responsiveness may be involved.
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PMID:Neuropeptide Y infusion improves hemodynamics and survival in rat endotoxic shock. 790 7

Despite the well-recognized vasoconstrictor and fluid-retaining actions of vasopressin, prolonged administration of arginine vasopressin (AVP) to normal animals or humans fails to produce sustained hypertension. The present study was performed to elucidate the role of the V1 receptor in determining the ability of AVP to produce sustained hypertension. Conscious Sprague-Dawley rats with implanted catheters were infused with the selective V1 agonist, [Phe2,Ile3,Orn8]vasopressin (2 ng.kg-1.min-1), for 14 days in amounts that were acutely nonpressor. Blood pressure (MAP), heart rate (HR), body weight, and water intake (WI) were determined daily. Plasma AVP, plasma catecholamines norepinephrine and epinephrine, plasma osmolality, and electrolyte concentration were determined before and on days 1 and 7 of infusion. MAP increased significantly by 10.4 +/- 4.5 mmHg on day 1 and rose to 22 +/- 5 mmHg above control by day 14 (transient decrease on days 6-9) and then fell to control levels after the infusion was stopped. HR did not change significantly. Plasma AVP immunoreactivity increased from 2.5 +/- 0.3 to 10.9 +/- 2.1 pg/ml, whereas norepinephrine tended to fall only on day 1, with epinephrine only slightly elevated on day 7. No evidence of fluid retention was found, and rats lost sodium only on the first day of V1 agonist infusion. Body weight increased throughout the study but was unrelated to the changes of MAP. We conclude that chronic stimulation of V1 receptors results in sustained hypertension in rats.
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PMID:Chronic intravenous administration of V1 arginine vasopressin agonist results in sustained hypertension. 806 31

2-(N-Propyl-N[(2'-[1H-tetrazol-5-yl]biphenyl-4yl)methyl]amin o) pyridine-3-carboxylic acid (ABBOTT-81988), a novel nonpeptide angiotensin II (AII) antagonist, was evaluated to characterize its antihypertensive activity in the conscious renal hypertensive rat. Oral or i.v. administration of ABBOTT-81988 at 0.03 to 0.3 mg/kg produced a dose-dependent, sustained decrease in mean arterial pressure (MAP; control 162-173 mm Hg, n = 27) of approximately 20 to 70 mm Hg. At a dose of 0.3 mg/kg p.o., ABBOTT-81988 lowered MAP to a normotensive level for more than 24 hr and did not change heart rate. During its antihypertensive effect (delta MAP, -28% approximately -35%), ABBOTT-81988 (0.1-03 mg/kg i.v.) decreased total peripheral resistance (delta resistance, -31% approximately -43%), and cardiac output remained either unchanged or slightly elevated. ABBOTT-81988 (0.3 mg/kg i.v.) produced an additional antihypertensive effect (delta MAP, -12 +/- 2%, n = 5) in captopril-pretreated (10 mg/kg i.v.) hypertensive rats, but captopril (10 mg/kg i.v.) had no effect in ABBOTT-81988-pretreated (0.3 mg/kg i.v.) rats. In the normotensive rat, ABBOTT-81988 (0.3 mg/kg p.o.) had no effect on basal MAP, but it inhibited the AII-induced (0.1 microgram/kg i.v.) pressor response by 51% to 91% for 24 hr, whereas the responses to norepinephrine (0.3 microgram/kg i.v.), vasopressin (0.03 IU/kg i.v.) and bradykinin (3 micrograms/kg i.v.) were not affected. It is concluded that ABBOTT-81988 is a safe and efficacious AII antagonist that may have use in the treatment of human hypertension.
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PMID:Characterization of antihypertensive activity of ABBOTT-81988, a nonpeptide angiotensin II antagonist in the renal hypertensive rat. 830 84

The experiments were designed to determine whether potassium-loaded rats have a deficient recovery of blood pressure after a rapid arterial haemorrhage. Potassium loading was achieved by providing a 0.75% KCl solution as drinking fluid for 14 days, while control rats had either distilled water or tapwater. MAP, HR, Hct, and plasma electrolytes were determined before and after 1 and 2% body weight haemorrhage in anaesthetized Sprague-Dawley rats. Potassium-loaded rats had significantly reduced blood pressure recovery within 20 min after haemorrhage. HR was significantly reduced within 5 min only after 2% haemorrhage in potassium-adapted rats. Haemorrhage induced significant hyperkalaemia which was greater and significantly prolonged after 2% haemorrhage. The significant fall in Hct after haemorrhage was not affected by the magnitude of haemorrhage. In an additional group of rats, the pressor response to intravenous infusion of vasopressin was unaffected by potassium loading, whereas that to noradrenaline and angiotensin II was significantly reduced throughout the 20 min of infusion. The peak increase in blood pressure after phenylephrine injection was, however, unaffected by potassium loading. Basal plasma catecholamines concentration as well as concentrations after 1% haemorrhage were unaffected by potassium loading. It is concluded that the reduced vascular response to noradrenaline and angiotensin contributed to the reduced recovery of blood pressure after haemorrhage in potassium-loaded rats. Furthermore, the result with phenylephrine suggest a mechanism that is unrelated to direct vascular effects of noradrenaline and angiotensin II.
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PMID:Cardiovascular and catecholamine responses to acute haemorrhage in anaesthetized potassium-adapted rats. 835 42

Vasopressin is a powerful vasoconstrictor that is released into the systemic circulation during exercise. We tested the hypothesis that this peptide contributes to the cardiovascular response during treadmill exercise in the pig. Seventeen miniswine were instrumented with epicardial electrocardiogram leads, left atrial and aortic catheters, and a left ventricular pressure transducer for measurement of heart rate (HR), regional blood flow, arterial blood pressure (MAP), and myocardial contractility [first derivative of left ventricular pressure (dP/dt) at 40 mmHg developed pressure] at rest and during exercise. At a work intensity of 80% of each animal's maximal HR reserve, exercise-induced increases in MAP, HR, dP/dt at 40 mmHg developed pressure, and cardiac output were measured. On a separate day, the workload performed by each animal was replicated in the presence of selective vasopressin V1-receptor inhibition using the specific V1 antagonist, [d(CH2)5Tyr(Me)]arginine vasopressin (10-14 micrograms/kg iv). During exercise, MAP was lower (96 +/- 3 vs. 104 +/- 2 mmHg) and cardiac output was higher (13.5 +/- 0.6 vs. 12.6 +/- 1.0 l/min) in the presence of V1-receptor blockade than during unblocked conditions, respectively. Furthermore, we observed an attenuation of exercise-induced decreases in blood flow to the colon. Increases in vascular resistance in the stomach, small intestine, colon, and pancreas also were diminished by V1-receptor inhibition. However, HR and myocardial contractile responses to exercise were not affected. These results suggest that vasopressin contributes to increases in MAP and to the redistribution of cardiac output during dynamic exercise in the miniswine.
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PMID:Vasopressin contributes to the cardiovascular response to dynamic exercise. 849 82

Treatment of rat 3Y1 fibroblasts with vasopressin (AVP) results in a transient activation of MAP kinase as potent as with EGF and serum. An antagonist of vasopressin receptor V1, but not an antagonist of V2, inhibited the AVP-induced activation of MAP kinases, indicating that AVP activates MAP kinases through V1 receptor. Prolonged TPA treatment of cells resulted in partial MAP kinase activation, indicating the presence of PKC-independent pathway. The pathway was inhibited by wortmannin, an inhibitor of PI3-kinase. The results suggest that wortmannin-sensitive molecules such as PI3-kinase, are involved in the V1 receptor-mediated activation of the MAP kinase pathway independent of TPA-sensitive PKC.
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PMID:Wortmannin inhibits the activation of MAP kinase following vasopressin V1 receptor stimulation. 854 62

Decreases in blood pressure are well known to increase the release of vasopressin. Studies were carried out to investigate whether vasopressin responses to postural changes in blood pressure are maintained in diabetic patients with orthostatic hypotension [DM-OH(+)] as well as non-diabetic patients with orthostatic hypotension [nonDM-OH(+)] and these responses were compared with those observed in normal subjects and diabetic patients without orthostatic hypotension [DM-OH(-)]. After 30 min in the supine position, the upright posture for 40 min was maintained and then the supine for 10 min. Blood pressure and heart rate (HR) were measured every 5 min and plasma vasopressin levels (plasma AVP) were determined every 10 min. In normal subjects and DM-OH(-), mean arterial blood pressure (MABP) did not change, but HR increased significantly by the upright position. Plasma AVP did not change in these groups. On the other hand, in DM-OH(+) MABP fell abruptly and remained to decrease during the upright posture. The HR responses in this group, however, were similar to those in normal control and DM-OH(-). Plasma AVP in DM-OH(+) significantly increased only at 30 min during upright. These increases were significantly greater than those in normal and DM-OH(-). There were significant correlation in changes in MABP (delta MAP) and plasma AVP (delta AVP) in DM-OH(+) (delta AVP = -0.13 MABP + 1.5, r = -0.32, p < 0.01). Relationship between delta MABP and delta AVP in nonDM-OH(+) was similar to that in DM-OH(+). It is concluded that AVP responses to orthostatic hypotension in diabetic and non-diabetic neuropathies were attenuated, but heart rate responses in these patients ware well reserved.
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PMID:Changes in plasma vasopressin levels and cardiovascular function due to postural changes in diabetic neuropathy. 869 86

Endothelins (ETs) were initially thought to be primarily involved in the control of cardiovascular activity, but the presence of ETs and their receptors in a wide variety of other tissues has suggested a much broader range of functions. Specific receptors for ETs are found in nonvascular tissues including neuronal, neuroendocrine, and endocrine cells. In addition, immunoreactive ETs are present in the brain, pituitary, and peripheral endocrine tissues. However, the ET levels in hypothalamo-hypophysial portal and peripheral blood are low, suggesting that the ET system participates in neuroendocrine regulation through paracrine and/or autocrine mechanisms. Both ETA and ETB receptors are expressed in the hypothalamus, adrenal, parathyroid glands, pancreas, ovary, uterus, placenta, and prostate, while only ETA receptors are expressed in GT1 neurons, anterior pituitary cells, alpha T3-1 immortalized gonadotropes, parathyroid-derived cells, thyrocytes, testicular Leydig and Sertoli cells, normal and neoplastic ovarian granulosa cells, chondrocytes, and other cell types. Activation of ET receptors elicits the sequence of cellular events typical of Ca(2+)-mobilizing receptors, with prominent increases in phosphoinositide hydrolysis and elevations of [Ca2+]i that occur in oscillatory and nonoscillatory modes depending on the cell type. ET-induced activation of the phosphoinositide/Ca(2+)- mobilizing pathway in neuronal and endocrine cells is associated with rapid stimulation of secretory responses, including release of gonadotropin-releasing hormone, oxytocin, vasopressin, substance P, atrial natriuretic peptides, gonadotropins, thyrotropin, growth hormone, parathyroid hormone, aldosterone, and catecholamines. On the other hand, ET has inhibitory actions on prolactin, progesterone, and renin release. In addition to stimulating phospholipase C-dependent pathways, ETs also activate phospholipase D-and MAP-kinase-dependent pathways in some of their target cells, as well as expression of early response genes and increased mitogenic activity. In many neuroendocrine cells, ET induces rapid and marked desensitization of its signaling system, in association with extensive internalization of ET receptors and reduced signaling and secretory responses. These findings raise the possibility that ETs participate in the control of secretory responses in the hypothalamo-pituitary system and peripheral endocrine cells, as well as in long-term aspects of regulation in certain neuroendocrine cells.
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PMID:Expression and signal transduction pathways of endothelin receptors in neuroendocrine cells. 881 99

We have shown previously that, in rats with deoxycorticosterone (DOC)-salt hypertension, arterial blood pressure rises more rapidly and reaches a higher level in male than in female rats and that the course of the hypertension was ameliorated by gonadectomy in male rats and exacerbated by gonadectomy in female rats. The present investigation was undertaken to examine the role of the gonadal steroid hormones in modulating the course of DOC-salt hypertension in the rat. Our previous findings with respect to the effects of gender and gonadectomy on DOC-salt hypertension were confirmed in this study. Chronic treatment with gonadal steroids was begun 1 week before the start of the DOC-salt protocol. 17 beta-Estradiol attenuated the course of the hypertension in intact male rats and in gonadectomized females. Testosterone exacerbated the development of the hypertension in gonadectomized male rats but was without effect in intact females. Progesterone alone had no effect on the hypertension in ovariectomized rats but when given to ovariectomized rats in combination with estradiol transiently prevented the ameliorating effect of the estradiol. These effects of the gonadal steroid hormones could not be attributed to effects of saline intake. Thus, these findings demonstrate that the gonadal steroid hormones play an important role in modulating the pathogenesis of DOC-salt hypertension in the rat. It is suggested that the effects of the gonadal hormones on the course of the hypertension may be due to modulation of the cardiovascular and renal actions of vasopressin, since vasopressin is required for this model of hypertension.
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PMID:Gonadal hormones modulate deoxycorticosterone-salt hypertension in male and female rats. 903 48


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