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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The vasoconstrictor and vasopressor actions of vasopressin have been revealed in recent research through the use of highly specific and sensitive radioimmunoassays, employment of peptide antagonists, and comparison with an animal model which has hereditary absence of this hormone, the Brattleboro rat. Factors now known to modify the pressor effect of vasopressin are the baroreflexes, local vascular prostaglandin production, and a specific interaction with angiotensin II. In experimental models the volume retaining, but not the vasoconstrictor effect of vasopressin is necessary for mineralocorticoid-salt hypertension. Vasopressin contributes directly to the increase in arterial pressure of glycerol induced acute renal failure. In nephrectomized rats, plasma vasopressin is elevated and contributes directly to maintenance of pressure. Vasopressin antagonism may reduce arterial pressure in Goldblatt 1 and 2 kidney hypertension and in one genetic model, spontaneously hypertensive rat (SHR), but the peptide is not necessary for hypertension in these models. Plasma vasopressin is reduced in primary aldosteronism, but may be elevated in malignant hypertension. In essential hypertension, there is considerable disagreement among various studies in which plasma vasopressin, urine vasopressin excretion, platelet associated vasopressin, or vasopressin-neurophysin were measured as to whether there is evidence for increased secretion of vasopressin. Only preliminary studies of vasopressin antagonism in clinical hypertension have been reported. At present, there is no conclusive evidence that elevated vasopressin secretion occurs or is necessary for any form of clinical hypertension.
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PMID:The role of vasopressin in experimental and clinical hypertension. 388 2

1. Recently it has been shown that injection of angiotensin II into the anterior diencephalon causes the rat to drink water. In the present experiments the dipsogenic action of a number of other substances including substances related to angiotensin was tested.2. Injection of 0.001 Goldblatt u. renin into the angiotensin-sensitive region causes the water-replete rat to drink. Drinking is slower in onset and continues for longer than after injection of angiotensin II.3. Synthetic tetradecapeptide renin substrate and angiotensin I were as effective as angiotensin II at causing water-replete rats to drink.4. beta-aspartic acid(1)-valine(5)-angiotensin II was also fully effective; but the D-arginine substituted octapeptide was much less effective.5. The (2-8) heptapeptide retained about 50% of the dipsogenic activity of the octapeptide, whereas the absence of phenylalanine at the other end of the peptide chain in the (1-7) heptapeptide results in an inactive compound.6. The (3-8) hexapeptide and the (4-8) pentapeptide, both of which have phenylalanine at the end of the chain, and the (1-4) and (5-8) tetrapeptide fragments of angiotensin II showed only a slight action on intake of water.7. Kallikrein, bradykinin, adenosine-3'5-cyclic phosphate, vasopressin and oxytocin caused no drinking when injected into the angiotensin-sensitive region.8. It is concluded that the requirements for the dipsogenic activity of angiotensin are the same as those for its other biological actions with the qualification that the precursor peptides are also active, presumably because they give rise to angiotensin II locally.
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PMID:The effect on drinking of peptide precursors and of shorter chain peptide fragments of angiotensin II injected into the rat's diencephalon. 432 62

The renal microcirculation was assessed in non-clipped kidneys of 23 Munich-Wistar rats with two-kidney one-clip Goldblatt hypertension. Four weeks after placement of a renal arterial clip, mean systemic arterial pressure averaged 163 +/- 5 mm Hg in hypertensive rats as compared to 108 +/- 2 in sham-operated controls (n = 6 rats). Non-clipped kidneys in hypertensive rats were characterized by higher glomerular capillary hydraulic pressures, single nephron glomerular filtration rate, and afferent arteriolar resistance. The glomerular capillary ultrafiltration coefficient was significantly reduced in hypertensive rats. In 10 of these rats, intravenous infusion of the angiotensin antagonist, saralasin, or the converting enzyme inhibitor, SQ20881, led to significant reductions in systemic arterial pressure and in afferent and efferent arteriolar resistance, on average by 8 +/- 3%, 15 +/- 4%, 28 +/- 5%, respectively. These changes were associated with significant increase in glomerular plasma flow, while ultrafiltration coefficient remained unaffected. In the presence of saralasin or SQ20881, infusion of a specific antagonist of the vascular action of arginine vasopressin led to significant systemic but not renal vasodilation. Thus, whereas systemic arterial pressure fell further, on average by 23 +/- 2%, renal arteriolar resistance remained constant, resulting in marked reduction in glomerular capillary hydraulic pressures (by 18 +/- 2%) and glomerular plasma flow rate (by 28 +/- 10%). Because of these pronounced reductions in glomerular pressures and flows induced by vasopressin antagonist, single nephron glomerular filtration rate fell markedly in hypertensive rats (by 34 +/- 6%) despite normalization of ultrafiltration coefficient. When hypertensive rats (n = 7) were treated with vasopressin antagonist alone, a modest fall in systemic arterial pressure was again observed in the absence of changes in renal arteriolar resistance. Due to this selective extrarenal vasodilatory action of vasopressin antagonist, glomerular capillary hydraulic pressure, plasma flow rate, and single nephron glomerular filtration rate again fell markedly. When these vasopressin antagonist pre-treated hypertensive rats were given saralasin or SQ20881, marked reductions in renal arteriolar resistance were observed in association with a significant increase in glomerular plasma flow rate. These observations made during acute inhibition of angiotensin II and vasopressin indicate that both of these vasopressin hormones may play important roles in maintaining systemic hypertension in hypertensive rat. By virtue of its preferential constrictor effects on extrarenal rather than renal vasculature vasopressin serves to maintain high glomerular pressures and flows in the non-clipped kidney of Goldblatt hypertensive rats.
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PMID:Relative contribution of vasopressin and angiotensin II to the altered renal microcirculatory dynamics in two-kidney Goldblatt hypertension. 619 14

The subfornical organ (SFO), one of the brain circumventricular organs, contains immuno-reactive arginine-vasopressin (AVP). AVP in the SFO area may originate in neurons of the hypothalamo-neurohypophysial system. If AVP in the SFO area is part of the magnocellular neuroendocrine system and is important in the regulation of hydration, then its concentration [(]) should change during prolonged dehydration. The SFO is also a target for angiotensin II when the peptide stimulates drinking and releases AVP from the hypothalamo-neurohypophysial system. For these reasons, it was reasoned that hormones of the renin-angiotensin system may also influence [AVP] in the SFO area. To test these hypotheses [AVP] was measured in the SFO area, hippocampal commissure-fornix (HC-F), neural lobe and plasma of rats after 24, 48 and 72 h of water deprivation and at various times after intracerebroventricular (i.v.t.) administration of 5 milli -Goldblatt Units of renin. Before examining the responsiveness of [AVP] in these brain regions to stimulation, we characterized the extraction and recovery of AVP from brain tissue and determined the variance of [AVP] in the SFO area and HC-F among different groups of animals. AVP was extracted from pooled brain tissue into 0.1 N HCl. The homogenate was centrifuged and AVP in the supernatant was quantified by radioimmunoassay either directly or after bentonite extraction. AVP extracted from the SFO area and HC-F displaced labelled antigen bound to antisera in a manner similar to that displaced by standard AVP. The recovery of AVP, added to the 0.1 N HCl extract and assayed directly, averaged 78-108%, whereas 51% was recovered after bentonite extraction. [AVP] in the SFO area from 47 or more groups of 2-6 organs each, averaged 16 +/- 5 pg/organ, 16 +/- 4 pg/mg wet wt, 153 +/- 31 pg/mg protein, and was not significantly different from that contained in the HC-F, 10 +/- 1 pg/mg wet wt and 111 +/- 16 pg/mg protein. A frequency histogram of these data revealed a normal (HC-F) and skewed distribution (SFO). Water deprivation for 24, 48 and 72 h stimulated drinking and increased plasma [AVP]. The elevation in plasma [AVP] plateaued after 48 and 72 h of water deprivation, whereas [AVP] in the neural lobe was reduced (P less than 0.05). Water deprivation increased [AVP] in the HC-F (control vs 72 h water deprivation), but did not alter hormone in the SFO area when expressed as pg/mg protein or pg/mg wet wt.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effects of dehydration and renin on vasopressin concentration in the subfornical organ area. 637 9

Plasma arginine vasopressin (AVP) levels were elevated in both one-kidney, one-clip [1K-1C) and two-kidney, one-clip (2K-1C) hypertensive Long-Evans rats. Homozygous Brattleboro rats with hereditary hypothalamic diabetes insipidus (DI), which are completely devoid of vasopressin, were made hypertensive using the 1K-1C Goldblatt models for renal hypertension. The 2K-1C DI rats developed hypertension at the same rate and to the same degree as normal 2K-1C hypertensive Long-Evans rats. The development of hypertension in 1K-1C DI rats was similar to the normal 1K-1C hypertensive Long-Evans rats. However, the absolute levels of systolic blood pressure reached were significantly less in the vasopressin-deficient rats. Treatment with 1-desamino-8-D-arginine vasopressin (DDAVP), the synthetic analogue of arginine vasopressin that has high antidiuretic but low pressor potencies, was associated with restoration of water balance in the volume-depleted DI rats and also restored blood pressure to hypertensive levels equivalent to the 1K-1C Long-Evans rats. These studies suggest that vasopressin is not essential for the development of experimental renal hypertension in rats but may contribute to the absolute levels of systolic blood pressure reached through its properties as an antidiuretic hormone.
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PMID:Role of vasopressin in hypertension: studies using the Brattleboro rat. 709 24

1. Homozygous Brattleboro rats with hereditary hypothalamic diabetes insipidus (DI) developed one-kidney, one-clip (1K-1C) and two-kidney, one-clip (2K-1C) Goldblatt renal hypertension. 2. However, the systolic blood pressure (SBP) in 1K-1C Brattleboro rats was significantly lower than in non-DI hypertensive 1K-1C Long-Evans (LE) rats. 3. Treatment with the synthetic antidiuretic analogue of vasopressin, DDAVP (1-desamino-8-D-arginine vasopressin), increased the SBP in the DI rats to the same level as in 1K-1C Long-Evans. This elevation of SBP was associated with increased extracellular fluid volume in the DI rats after DDAVP. 4. The results suggest that vasopressin is not essential for the development of renal hypertension but the absolute levels of blood pressure achieved in 1K-1C hypertension are volume-dependent and thus influenced by the water-retaining properties of vasopressin.
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PMID:Importance of antidiuretic properties of vasopressin in experimental renal hypertension. 732 74

Valsartan, a selective antagonist of angiotensin II at the AT(1) receptor subtype, is an efficacious, orally active, blood pressure-lowering agent used in hypertensive patients. Given that aminopeptidases (APs) play a major role in the metabolism of local peptides involved in blood pressure control, studying them helped us to understand cardiovascular control. We studied the effect of valsartan on angiotensin II- (GluAP) and vasopressin- (CysAP) degrading activities in the kidney in the rat model of renovascular hypertension, Goldblatt two-kidney one-clip. GluAP and CysAP in renal cortex and medulla exhibited different responses to hypertension and valsartan treatment. In the renal cortex, GluAP decreased in clipped and non-clipped kidneys of hypertensive animals. However, while hypertension did not affect GluAP in the clipped kidney medulla, the non-clipped kidney exhibited an increase in soluble and a decrease in membrane-bound activity. Valsartan decreased soluble GluAP in the medulla of normotensive and hypertensive animals. In the renal cortex, CysAP activity was mainly downregulated following hypertension. Valsartan decreased soluble CysAP activity in sham-operated, but not in hypertensive animals. The renal medulla showed a significant valsartan-related decreased activity in clipped and non-clipped kidneys of both sham-operated and hypertensive animals. These results suggest a functional relationship between the AT(1) receptor and vasopressin-degrading activity.
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PMID:Effect of valsartan on angiotensin II- and vasopressin-degrading activities in the kidney of normotensive and hypertensive rats. 1156 Dec 17


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