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 have demonstrated in liver from male rats that both endothelin A (ETA) and ETB receptors coexist in equal proportion and that ETA receptors mediate a calcium-dependent activation of glycogenolysis. We describe here a sex difference in endothelin action in hepatocytes because, in female rats, 80% of the ET receptors are of ETB type and, accordingly, activation of glycogenolysis is an ETB-mediated process (EC50 = 0.03 pM). ET-1 stimulation of glycogenolysis in female rats was consecutive to activation of phosphatidylinositol 4,5-bisphosphate hydrolysis (EC50 = 0.03 pM) and to inhibition of the calcium extrusion pump (IC50 = 0.03 pM) in plasma membranes, with ET-1 approximately sarafotoxin S6C approximately ET-3. Endothelin regulation of each effector was potentiated by GTP gamma S. ET-1 did not stimulate adenylyl cyclase activity. To identify the nature of the guanine nucleotide regulatory proteins (G protein(s)) coupling ETB receptors to each effector, we used antibodies against the COOH terminus of different G protein alpha subunits. Antibodies reactive with Gs alpha (RM) blocked ET-1 inhibition of the calcium pump, while they did not affect ET-1 stimulation of phospholipase C. Antibodies reactive with Gq alpha (QL) dose-dependently antagonized stimulation of phospholipase C by ET-1 and vasopressin, without affecting ET-1 inhibition of the calcium pump. Antibodies reactive with Gi1 alpha/Gi2 alpha (AS) had no effect on either system. We conclude that the calcium signal provoked by endothelins in hepatocyte is not only consecutive to activation of phospholipase C but also to inhibition of the plasma membrane calcium pump, each effector being coupled to ETB receptors by different G proteins, Gq, and Gs.
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PMID:Coupling of endothelin B receptors to the calcium pump and phospholipase C via Gs and Gq in rat liver. 829 32

The intracellular localization of immunoreactive endothelin (ET)-1, and its colocalization with vasopressin (VP) and oxytocin (OT) in the rat neural lobe were investigated by immunogold techniques using specific antisera raised against ET-1, VP, and OT. There were two types of axons: the first contained VP-immunolabeled neurosecretory granules, and the second contained OT-immunolabeled neurosecretory granules. A considerable number of the neurosecretory granules in both types of axon were immunolabeled with antibodies against ET-1, although the VP-immunolabeled granules were more heavily labeled with anti-ET-1 antiserum than OT-immunolabeled ones. Double immunogold labeling clearly demonstrated the intragranular colocalization of immunoreactions for ET-1 and VP and that of immunoreactions for ET-1 and OT. These results suggest that ET in the neural lobe may be released concomitantly with neurohypophysial hormones. Its biological significance remains to be elucidated.
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PMID:Colocalization of immunoreactive endothelin-1 and neurohypophysial hormones in the axons of the neural lobe of the rat pituitary. 842 73

We assessed various aspects of endocrine function in patients treated for essential hypertension with manidipine chloride, a calcium channel blocker, to study the effects of this drug on several endogenous humoral factors, including human atrial natriuretic peptide (hANP) and endothelin 1 (ET), which influence vasoconstriction and blood fluid volume. The study included 19 patients with essential hypertension. All patients received manidipine chloride 10 mg/d for 24 weeks. After treatment blood pressure was normalized in all patients, and there were no significant changes in plasma renin activity or blood concentrations of vasopressin, hANP, ET, aldosterone, adrenaline, or noradrenaline. There was a statistically significant negative correlation between the change in ET levels and hANP levels before and after treatment. We also observed a statistically significant negative correlation between the change in systolic blood pressure caused by manidipine chloride and the change in hANP levels before and after treatment. These findings suggest that hANP and ET levels are systematically changed by manidipine chloride in patients with essential hypertension. We also speculate that changes in blood pressure may be closely related to levels of hANP in patients treated with manidipine chloride.
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PMID:Effect of manidipine chloride on various aspects of endocrine function, including plasma levels of endothelin-1 and human atrial natriuretic peptide, in patients with essential hypertension. 887 96

This review describes recent progress in the accumulation of knowledge about the endothelins (ETs), a family of vasoactive 21-amino acid polypeptides, in chronic liver disease. Particular prominence is given to the dynamics of ET-1 and ET-3 and their possible relation to the disturbed circulation and neurohumoral dysregulation found in cirrhosis. Recent studies have shown that the ET system is highly activated in most cirrhotic patients. Circulating ET-1 and ET-3 levels have a positive relation to the severity of the disease and fluid retention, with the highest values recorded in patients with functional renal failure. Studies on liver biopsies have revealed synthesis of ET-1 in hepatic endothelial and other cells, and recent investigations have identified the hepatosplanchnic system as a major source of ET-1 and ET-3 spillover into the circulation, with a direct relation to portal venous hypertension. In addition, marked associations with disturbance of systemic haemodynamics and with abnormal distribution of blood volume have been reported. Although the pathophysiological importance of the ET system in chronic liver disease is not completely understood, similarities to other vasopressive and antinatriuretic regulatory systems (i.e. the sympathetic nervous system, renin-angiotensin-aldosterone and vasopressin) are apparent, with respect to kinetics and haemodynamic dysregulation. Cirrhosis seems to be a pathophysiological condition with indications of the occurrence of ETs, not only as local modulators, but also as a system with potential importance for systemic regulation.
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PMID:Endothelins in chronic liver disease. 890 9

Endothelins (ET) within the central nervous system (CNS) alter systemic cardiovascular responses and arginine vasopressin (AVP) secretion. These experiments were designed to ascertain whether the rise in systemic arterial pressure after central administration of ET-1 is mediated by enhancing sympathetic outflow and/or circulating AVP. In Long-Evans (LE/LE) rats, intracerebroventricular injection of 1-10 pmol ET-1 dose dependently increased mean arterial pressure (MAP). Peak response occurred 7-12 min after ET-1 and was inhibited by ETA receptor antagonism. Systemic vasopressin (V1) receptor blockade did not inhibit the pressor response, and rats with central diabetes insipidus (DI/DI) displayed an identical rise in MAP. Ganglionic blockade prevented ET-1-induced hemodynamic effects. Peak plasma AVP levels occurred 60 min after ET-1, as the pressor response began to wane. In sinoaortic-denervated LE/LE rats, ET-1 elicited a 10-fold increase in AVP secretion that coincided with the hemodynamic changes and was blocked by BQ-123. Thus ET-1 via ETA receptors within the CNS induced a concentration-dependent increase in systemic arterial pressure mediated by enhanced sympathetic outflow but not by circulating AVP. Reflex baroreceptor activation attenuated AVP release.
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PMID:Mechanisms of centrally administered ET-1-induced increases in systemic arterial pressure and AVP secretion. 903 61

The effects of bosentan (Ro 47-0203), an endothelin A and B receptor antagonist, on responses to endothelin-1, sarafotoxin 6c, angiotensin II, and arginine vasopressin were investigated in the hind-limb vascular bed of the cat. Under constant-flow conditions, intraarterial injections of endothelin-1 and sarafotoxin 6c induced biphasic changes in hind-limb perfusion pressure characterized by an initial decrease followed by a secondary increase in perfusion pressure. The vasodilator and vasoconstrictor components of the biphasic responses to endothelin-1 and sarafotoxin 6c were reduced by bosentan, and the endothelin receptor antagonist reduced baseline systemic arterial and hind-limb perfusion pressures. Bosentan decreased vasoconstrictor responses to lower doses of angiotensin II, whereas responses to higher doses of angiotensin II and responses to vasopressin, U46619, BAY K8644, norepinephrine, acetylcholine, bradykinin, levcromakalim, PGE1, adrenomedullin, and calcitonin gene-related peptide were not altered. Vasoconstrictor responses to ET-1 were not altered by the angiotensin AT1 receptor antagonist DuP 532 or the AT2 receptor antagonist PD123,319. The results of the present study show that bosentan attenuates vasodilator and vasoconstrictor responses to endothelin-1 and sarafotoxin 6c and vasoconstrictor responses to lower doses of angiotensin II in the hind-limb vascular bed of the cat. These results suggest that endothelin may be involved in mediating responses to lower doses of angiotensin II and in the maintenance of baseline tone in the systemic vascular bed of the cat.
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PMID:Analysis of effects of bosentan (Ro 47-0203), a nonpeptide endothelin ETA/ETB receptor antagonist, in the hind-limb vascular bed of the cat. 963 52

In a new model of spontaneous hypertension, namely the Prague hypertensive rat (PHR), hypertension is transferred with a kidney transplanted from the PHR to its normotensive counterpart (PNR) by an as yet unknown mechanism. One candidate may be endothelin (ET), since this potent vasoconstrictor affects vascular tone, renal haemodynamics and renal excretory function, and all members of this peptide family are located within the kidney and act in an autocrine/paracrine fashion. In the present study we investigated, in the renal tissue of PHRs and PNRs: (1) preproET-1 and preproET-3 mRNAs as well as ET-1 and ET-3 peptide distribution, (2) endothelin-converting enzyme (ECE)-1 mRNA expression, and (3) ET receptors and their characteristics in membranes of glomeruli and papillae. In addition, plasma ET concentration and urinary ET excretion were determined. Quantitative measurements by competitive reverse transcription-polymerase chain reaction revealed ET-1 mRNA levels in the renal cortex from PHRs and PNRs of 1.09+/-0.13 and 1. 29+/-0.18 amol/microgram of total RNA respectively, and in red medulla of 2.72+/-0.82 and 3.30+/-0.68 amol/microgram respectively. In contrast, renal papilla from PHRs showed significantly lower levels of preproET-1 mRNA (1.81+/-0.64 amol/microgram of total RNA, compared with 4.25+/-0.82 amol/microgram in PNRs; each n=5; P<0.05). The ET-1 peptide concentration in papillary tissue was also significantly lower in PHRs than in PNRs (120.2+/-30.8 and 491.3+/-53.4 fmol/mg of protein respectively; n=5; P<0.01), whereas it was similar in cortex and medulla from PHRs and PNRs. The preproET-3 mRNA content in renal tissue was much lower than that of preproET-1 mRNA. It was significantly higher in red medulla from PHRs compared with that from PNRs (0.25+/-0.05 and 0.13+/-0.02 amol/microgram of total RNA respectively; P<0.05), but was similar in papillae of PHRs and PNRs (0.04+/-0.02 and 0.05+/-0.01 amol/microgram respectively; n=5). Cortical preproET-3 mRNA was at the lower limit of detection. Similarly, the ET-3 peptide concentration was slightly but significantly higher in the red medulla of PHRs compared with PNRs (15.4+/-2.0 and 8.8+/-0.8 fmol/mg of protein respectively; n=5; P<0. 05), whereas no differences in ET-3 peptide concentration were found in papillae from PHRs and PNRs. ECE-1 mRNA levels were similar in the renal cortex, red medulla and papillae from PHRs and PNRs, ranging between 0.34+/-0.03 and 0.56+/-0.12 amol/microgram of total RNA. Of the total ET receptors in glomerular membranes, 39% were ETA receptors, whereas papillary membranes contained exclusively ETB receptors. PHRs and PNRs showed similar Bmax and Kd values for ET-1 in renal glomerular membranes (Bmax, 6.5+/-1.3 and 4.9+/-1.2 pmol/mg of protein respectively; Kd, 0.69+/-0.10 and 0.56+/-0.10 nM respectively) and papillary membranes (Bmax, 9.7+/-1.1 and 11.3+/-1. 6 pmol/mg of protein respectively; Kd, 0.30+/-0.04 and 0.42+/-0.07 nM respectively). Plasma ET-1/2 concentrations (10.4+/-1.3 and 12. 2+/-1.2 fmol/ml in PHRs and PNRs respectively) and urinary ET-1 excretion (3.1+/-0.3 and 3.0+/-0.2 pmol/24 h in PHRs and PNRs respectively) were similar in hypertensive and normotensive rats. In summary, although tissue levels of preproET-3 mRNA were very low in the kidney, significantly greater amounts of preproET-3 mRNA and ET-3 peptide were found in medullary tissue from PHRs compared with PNRs, a finding that awaits further investigation. In contrast, the preproET-1 mRNA content and ET-1 peptide concentration were significantly lower in papillary tissue from PHRs compared with PNRs. Decreased synthesis of ET-1, which normally antagonizes the action of [Arg8]vasopressin, may allow increased water (and sodium) reabsorption at the level of the inner medullary collecting duct. This intrinsic defect of the kidney in the PHR may contribute to hypertension in this model, and may transmit high blood pressure on transplantation of the 'hypertensive' kidney i
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PMID:The renal endothelin system in the Prague hypertensive rat, a new model of spontaneous hypertension. 1036 99

This study sought to identify whether central endothelin (ET) receptor activation contributes to the elevated pressure in spontaneously hypertensive rats (SHR) and whether an ET-stimulated vasopressin (AVP) release mediates the increased pressure. In Wistar Kyoto (WKY) rats, intracerebroventricular ET-1 induced a dose-dependent pressor response that was shifted rightward in SHR. ET(A) antagonism decreased mean arterial pressure in baroreflex-intact SHR (P<0.01), consistent with inhibition of endogenous ET-1, and blocked the pressor response to exogenous ET-1 in both strains. ET-1 increased AVP only after sinoaortic denervation (P<0.05). Contrary to WKY, sinoaortic denervation was required to elicit a significant pressor response with 5 pmol ET-1 in SHR. Sinoaortic denervation permitted ET-1 to increase AVP in both strains, and peripheral V(1) blockade decreased pressure in denervated but not intact rats. After nitroprusside normalized pressure in SHR, the pressor and AVP secretory responses paralleled those in WKY. Thus endogenous ET(A) receptor mechanisms contribute to hypertension, independent of AVP, in baroreflex-intact SHR. Although blunted in the hypertensive state, the arterial baroreflex buffers the ET-1-induced pressor and AVP secretory responses in both strains.
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PMID:Endothelin-1 in hypertension in the baroreflex-intact SHR: a role independent from vasopressin release. 1089 18

Plasma vasoactive hormone concentrations [epinephrine (p(Epi)), norepinephrine (p(NE)), ANG II (p(ANG II)), vasopressin (p(VP)), endothelin-1 (p(ET-1))] and plasma renin activity (p(RA)) were measured periodically and compared during lower body negative pressure (LBNP) to test the hypothesis that responsiveness of the renin-angiotensin system, the latter being one of the most powerful vasoconstrictors in the body, is of major importance for LBNP tolerance. Healthy men on a controlled diet (2,822 cal/day, 2 mmol. kg(-1). day(-1) Na(+)) were exposed to 30 min of LBNP from -15 to -50 mmHg. LBNP was uneventful for seven men [25 +/- 2 yr, high-tolerance (HiTol) group], but eight men (26 +/- 3 yr) reached presyncope after 11 +/- 1 min [P < 0.001, low-tolerance (LoTol) group]. Mean arterial pressure (MAP) did not change measurably, but central venous pressure and left atrial diameter decreased similarly in both groups (5-6 mmHg, by approximately 30%, P < 0.05). Control (0 mmHg LBNP) hormone concentrations were similar between groups, however, p(RA) differed between them (LoTol 0.6 +/- 0.1, HiTol 1.2 +/- 0.1 ng ANG I. ml(-1). h(-1), P < 0.05). LBNP increased (P < 0. 05) p(RA) and p(ANG II), respectively, more in the HiTol group (9.9 +/- 2.2 ng ANG I. ml(-1). h(-1) and 58 +/- 12 pg/ml) than in LoTol subjects (4.3 +/- 0.9 ng ANG I. ml(-1). h(-1) and 28 +/- 6 pg/ml). In contrast, the increase in p(VP) was higher (P < 0.05) in the LoTol than in the HiTol group. The increases (P < 0.05) for p(NE) were nonsignificant between groups, and p(ET-1) remained unchanged. Thus there may be a causal relationship between attenuated activation of p(RA) and p(ANG II) and presyncope, with p(VP) being a possible cofactor. Measurement of resting p(RA) may be of predictive value for those with lower hypotensive tolerance.
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PMID:Low LBNP tolerance in men is associated with attenuated activation of the renin-angiotensin system. 1095 39

Vasoconstrictor agents may induce a decrease in hepatic vascular volume passively, by decreasing distending pressure, or actively, by stimulating contractile elements of capacitance vessels. Hepatic venular resistance was estimated in anesthetized rabbits from hepatic venular pressure (P(mu hv); by servo-null micropipette), inferior vena cava pressure, and total hepatic blood flow (F(hv); by ultrasound flow probe). Changes in liver volume were estimated from measures of liver lobe thickness. Angiotensin (ANG) II, endothelin (ET)-1, norepinephrine (NE), and vasopressin (VP) were infused into the portal vein at a constant rate for 5 min. We conclude that ANG II and NE induced active constriction of hepatic capacitance vessels, because the liver lobe thickness decreased significantly even though P(mu hv) and portal venous distending pressure (P(pv)) increased. All four agents increased splanchnic and hepatic venous resistances in similar proportions. With VP, P(mu hv) and P(pv) decreased, but with ET-1, P(mu hv) and P(pv) increased. However, lobe thickness was not significantly changed by either drug during the infusion compared with the 2-min control period. Thus VP and ET-1 have only minor effects on hepatic capacitance vessels. ET-1, at 0.04 microg. min(-1). kg body wt(-1), caused an increase in systemic arterial blood pressure, but erythrocyte movement through the sinusoids in some animals stopped.
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PMID:Active and passive liver microvascular responses from angiotensin, endothelin, norepinephrine, and vasopressin. 1099 78


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