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)

Responses of blood pressure to intravenous (i.v.) or intracerebroventricular (i.c.v.) endothelin-1 (ET-1) in spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) rats were investigated. Conscious male SHRs and WKY rats were used for the experiments. ET-1 (300-1,000 ng/kg) was injected intravenously in the i.v. experiments, or 30 and 100 ng/kg of ET-1 were injected into the lateral ventricle in the i.c.v. experiments. The initial depressor response to i.v. ET-1 was greater in SHRs (n = 10) than in WKY rats (n = 10) at 1,000 ng/kg (-54 +/- 6 vs. -41 +/- 3 mm Hg, mean +/- SEM, p less than 0.05). The subsequent pressor response to i.v. ET-1 was smaller in SHRs than in WKY rats (3.5 +/- 0.8 vs. 7.0 +/- 0.9 mm Hg at 300 ng/kg, p less than 0.05, and 11 +/- 2 vs. 17 +/- 2 mm Hg at 1,000 ng/kg, p less than 0.05). Pressor responses to i.c.v. ET-1 were not different in SHRs (n = 8) and WKY rats (n = 8) at both doses (10 +/- 4 vs. 10 +/- 3 mm Hg at 30 ng/kg, and 46 +/- 10 vs. 49 +/- 10 mm Hg at 100 ng/kg). A greater initial depressor response and a smaller subsequent pressor response to i.v. ET-1 were observed in SHRs than in WKY rats. The attenuated pressor response to intravenously administered ET-1 may be unique since vasoconstrictor responses to other known vasoactive substances such as angiotensin, catecholamines, or vasopressin are reportedly augmented in SHRs. We did not find any difference in responsiveness to i.c.v. ET-1 between SHRs and WKY rats.
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PMID:Blood pressure responses to intravenous or intracerebroventricular endothelin-1 in spontaneously hypertensive rats. 172 61

Endocrine and renal parameters were measured in a desert rodent, Meriones crassus. In virgin females, the urine and plasma osmolality was 2018 +/- 136 and 325 +/- 3 mosm/kg (m +/- SEM), the level of circulating vasopressin, 162 +/- 22 pg/ml and the plasma renin activity 14.3 +/- 0.9 ng/ml per h. During pregnancy, the renin-angiotensin system was activated, and the plasma vasopressin values remained similar to those of virgin animals in spite of a lower blood plasma osmotic pressure. During this period, the regulation of the hydromineral balance was modified. These data suggest a lowering of the osmotic thresholds for vasopressin and possibly also for thirst during pregnancy in this desert rodent.
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PMID:[Osmolality and secretion of vasopressins during pregnancy in Meriones crassus]. 176 12

To examine the relationship between corticotrophin releasing hormone (CRH), arginine vasopressin (AVP) and oxytocin (OXT) we have studied the responses of adenohypophyseal and neurohypophyseal hormones to CRH in eight patients (age 26-64 years, six female) with suspected pituitary-dependent Cushing's syndrome during bilateral, simultaneous inferior petrosal sinus catheterization. Blood samples were taken from both petrosal sinuses and a peripheral vein before, and at 5-min intervals for 15 min after, an intravenous injection of 100 micrograms human CRH1-41. CRH increased sinus AVP concentrations in all eight patients and OXT concentrations in four of five patients studied. Although AVP concentrations often increased in both sinuses, the side of maximal AVP rise was termed side(max-AVP). CRH did not affect peripheral or petrosal sinus mean concentrations of LH, FSH, GH or TSH. While there was no change in mean peripheral concentrations of AVP, OXT, ACTH, ACTH precursors or prolactin after CRH, sinus concentrations of OXT, ACTH and prolactin on side(max-AVP) were markedly elevated over contralateral values. CRH did not increase mean sinus concentrations of ACTH precursors. In seven patients with either no radiological abnormality or the pituitary fossa or a small adenoma the mean ACTH precursor/ACTH ratio in blood sampled from all sites was 2.1 +/- 0.16 (mean +/- SEM, n = 50). In a patient with a large, locally invasive tumour the mean ACTH precursor/ACTH molar ratio was 32.1 +/- 1.3 (n = 12; P less than 0.001), suggesting that alterations in this molar ratio may reflect the biological properties of the tumour. The source of CRH-stimulatable AVP and OXT remains uncertain.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Corticotrophin releasing hormone (CRH1-41) stimulates the secretion of adrenocorticotrophin, vasopressin and oxytocin but not adrenocorticotrophin precursors: evidence from petrosal sinus sampling in man. 184 86

The plasma vasopressin and serum cortisol concentrations were recorded in 7 healthy volunteers receiving an intravenous infusion of 1 l of isosmotic (2.2%) glycine solution during 20 min. The infusion elicited a significant increase in the plasma vasopressin level by a mean of 60% (SEM 13) above baseline level. The serum cortisol level increased only in the patient who developed signs of glycine toxicity. These results suggest that a glycine solution has water-retaining properties by stimulating the vasopressin secretion but usually not by increasing cortisol secretion.
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PMID:Vasopressin and cortisol levels in response to glycine infusion. 187 56

Large arteries contribute to the regulation of cerebral blood flow. The goal of this study was to examine the effects of changes in diameter of the basilar artery on blood flow to the brain stem. We measured blood flow with laser-Doppler flowmetry in anesthetized rats. The topical application of 10(-6) M serotonin, which selectively constricts large arteries, reduced diameter of the basilar artery by 47 +/- 5% (mean +/- SEM, n = 6) but did not alter blood flow to the ventral brain stem (change in blood flow -2 +/- 5%). The topical application of 10(-8) M vasopressin, which affects both large and small vessels, decreased blood flow by 33 +/- 4% (n = 6). In rats with spontaneous vasomotion, the basilar artery showed rhythmic changes in diameter at a frequency of 4.0 +/- 0.1 cycles/min and an amplitude of 20 +/- 1% of mean diameter (n = 6). Blood flow to the ventral brain stem cycled at the same frequency as and in phase with changes in diameter of the basilar artery, with an amplitude of 15 +/- 1%. We conclude that constriction of the basilar artery may occur with no change in brain stem perfusion. The distinct changes in blood flow during spontaneous vasomotion suggest that vasomotion occurs in intraparenchymal arterioles as well as in the basilar artery.
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PMID:Role of the basilar artery in regulation of blood flow to the brain stem in rats. 190 28

1. Oxytocin receptors in the uterus of the brushtail possum (T. vulpecula) were characterized by radioreceptor assay and compared with those of the sheep and rat uterus. 2. A single oxytocin binding site was found with an affinity (Kd) and receptor concentration (Ro) of 3.0 +/- 0.8 nmol/l and 200 +/- 60 fmol/mg protein, respectively (SEM; n = 5). The receptor was stable at -20 degrees C; divalent ions were required for optimum binding. 3. Competitive displacement curves with related peptides showed the following order of specificity: vasotocin greater than oxytocin greater than mesotocin = arginine-vasopressin = [Thr4, Gly7]-oxytocin greater than lysine-vasopressin = isotocin much greater than [d(CH2)5, D-Phe2, Ile4, Ala9-NH2]-AVP. 4. It was concluded that oxytocin receptors in the possum have similar characteristics to those of placental mammals.
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PMID:Uterine oxytocin receptors in an Australian marsupial, the brushtail possum, Trichosurus vulpecula. 196 6

To examine if chronic sodium loading on the brain produces sustained increases in blood pressure, water intake, and sodium excretion, hypertonic (0.5 M and 1.5 M) and isotonic (0.15 M) NaCl solutions were infused into the third ventricle of Sprague-Dawley rats at a rate of 5.5 microliters/hr for 7 days. Intracerebroventricular infusion of 1.5 M NaCl significantly increased systolic blood pressure during the entire infusion period (+23 +/- 5 mm Hg on day 1 and +15 +/- 2 mm Hg on day 7, n = 10, mean +/- SEM). Blood pressure rose insignificantly in the 0.5 M NaCl group, whereas it remained at the baseline levels in the 0.15 M NaCl group. The increases in water intake (day 2), positive water balance (day 2), and negative sodium balance (day 3) were observed in the 1.5 M NaCl group. On day 7, the 1.5 M NaCl group showed hyponatremia and low plasma osmolality and had higher plasma norepinephrine but not vasopressin compared with the 0.15 M NaCl group. In another series of study, depressor response to intravenous hexamethonium (20 mg/kg) in the 1.5 M NaCl group was greater than that in the 0.15 M NaCl group on both day 1 and 7. The depressor response to d(CH2)5Tyr(Me)-arginine vasopressin (10 micrograms/kg) in the 1.5 M NaCl group was greater on day 1 but not on day 7. These results indicate that sustained sodium stimulus on the central nervous system causes mild hypertension and alters water and sodium balance. The sympathetic nervous system but not vasopressin may play an important role in the chronic phase of central NaCl-induced hypertension.
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PMID:Effects of chronic intraventricular sodium on blood pressure and fluid balance. 198 80

We examined the "vascular waterfall" hypothesis, which proposes that coronary flow is unaffected by elevations in outflow pressure until the latter reaches a critical threshold level, in 29 isolated canine hearts. In fibrillating hearts vasodilated with adenosine or carbocromen, coronary flow and the coronary pressure-flow relation were not affected by changes in great cardiac vein pressure (PGCV) below a threshold value of 11 +/- 0.9 (mean +/- SEM) mm Hg. Further elevations of PGCV reduced flow and shifted the pressure-flow relation to the right, increasing its pressure-axis intercept (Pf=0). When vasomotor tone was augmented with vasopressin, threshold PGCV increased to 25 +/- 2.7 mm Hg (p less than 0.001). Once again, the pressure-flow relation was unaffected by changes in PGCV below the threshold value and shifted to the right when this value was exceeded. The amount by which spontaneous values of Pf=0 exceeded threshold values of PGCV was greater when vasomotor tone was augmented than during vasodilation. Pf=0 continued to exceed PGCV when the latter was raised above the threshold level. Both Pf=0 and threshold values of PGCV were less during a long diastole than during ventricular fibrillation. We reached the following conclusions. 1) During changes in PGCV below a threshold value, the coronary circulation exhibits traditional waterfall behavior. 2) The threshold pressure for altering waterfall behavior is affected by vascular tone and mechanical activity. 3) Pf=0 remains above PGCV when the latter is increased above the threshold value needed to alter flow.
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PMID:Tone-dependent waterfall behavior during venous pressure elevation in isolated canine hearts. 199 45

Angiotensin II, when given in low doses, raises blood pressure slowly. When tested in vitro on vascular smooth muscle cells, it has mitogenic and trophic effects; it is not known if it has these effects in vivo. Our purpose was to determine whether vascular hypertrophy develops during slow pressor infusion of angiotensin II and, if so, whether it is pressure induced. Three experiments were done in rats infused subcutaneously with angiotensin II (200 ng/kg/min) by minipump for 10-12 days. Experiment 1: Angiotensin II gradually raised systolic blood pressure (measured in the tail) from 143 +/- 2 to 208 +/- 8 mm Hg (mean +/- SEM), significantly suppressing plasma renin and increasing threefold (NS) plasma angiotensin II. There was no loss of peptide in the pump infusate when tested at the end of the experiment. Experiment 2: In the perfused mesenteric circulation, vasoconstrictor responses to norepinephrine, vasopressin, and KCl were enhanced in rats given a slow pressor infusion of angiotensin II, but sensitivity of responses was not altered. This combination of changes suggests that vascular hypertrophy develops during slow pressor infusion of angiotensin II. Experiment 3: Vessel myography was done after angiotensin II infusion with and without a pressor response. Angiotensin II raised systolic blood pressure, increased heart weight, and produced myographic changes of vascular hypertrophy in the mesenteric circulation, increasing media width, media cross-sectional area, and media/lumen ratio. Hydralazine given with angiotensin II prevented the rise of pressure and the cardiac effect but not the vascular changes. Two-way analysis of variance showed that angiotensin II significantly increased media width, media cross-sectional area, and media/lumen ratio, all independent of hydralazine. Thus, although hydralazine inhibits the pressor and cardiac effects of angiotensin II, suggesting a pressor mechanism for the cardiac change, it does not inhibit structural vascular change, which suggests that at least part of the effect has a non-pressor mechanism.
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PMID:Angiotensin II causes vascular hypertrophy in part by a non-pressor mechanism. 202 7

A vasopressin and oxytocin containing nucleus is described for the first time in the pig hypothalamus. It is located near the third ventricle, just dorsal to the suprachiasmatic nucleus, and consists of magnocellular neurons, similar to those of the supraoptic nucleus and paraventricular nucleus. Morphometric analysis of neuronal number, size, density, and volume was performed at four different ages: 1 day, 7 weeks, 16 weeks, and 30 weeks postnatally. No sex difference in these parameters was observed. In this period the volume of the nucleus increased gradually from 6.6 x 10(-3) to 54.2 x 10(-3) mm3. One day after birth 1,215 +/- 191 (mean +/- SEM) neurons were present in the vasopressin and oxytocin containing nucleus, followed by a decrease to 771 +/- 80 neurons at 7 weeks and 697 +/- 116 at 16 weeks. Between 16 and 30 weeks (puberty) there was a dramatic increase in neuron number up to 1,765 +/- 214 neurons. This increase in the number of vasopressin and oxytocin containing neurons in the pig hypothalamus is much later in development than has ever been reported so far.
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PMID:A vasopressin and oxytocin containing nucleus in the pig hypothalamus that shows neuronal changes during puberty. 207 51


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