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

The effect of an iv infusion of somatostatin (SRIH) (4.1 micrograms/min x 90 min) on the basal secretion of arginine-vasopressin (AVP) and on the AVP response to insulin (0.15 IU/Kg) - induced hypoglycemia was studied in 6 normal men. Basal AVP secretion was not modified by SRIH administration. The blood glucose decrements induced by insulin were similar in the control insulin-tolerance test (ITT) and in the ITT + SRIH test, whereas the AVP response to hypoglycemia was significantly lower in the presence of SRIH. The mean peak AVP increase was three times higher than the basal value in the control ITT, but only two times during SRIH administration. Infusion of higher doses of SRIH (7 micrograms/min x 90 min) produced similar results. These data suggest the involvement of a somatostatinergic mechanism in regulation of AVP response to hypoglycemia.
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PMID:The infusion of somatostatin reduces the arginine-vasopressin response to insulin-induced hypoglycemia in man. 257 92

A 51-yr-old male patient with Cushing's syndrome due to huge nodular adrenocortical hyperplasia is described. Urinary 17-OHCS was not suppressed by a high dose of (8 mg) dexamethasone and showed rather a tendency to paradoxical response. There was no response to metyrapone. Plasma cortisol showed a hyperresponse to insulin-induced hypoglycemia and a rapid response to corticotropin releasing hormone-lysine vasopressin (CRH-LVP) administration without an obvious ACTH response. Plasma cortisol responded to synthetic ACTH. Urinary 17-OHCS did not show parallel changes with plasma cortisol. These results and computerized tomography data suggested huge multiple nodular adrenocortical hyperplasia, which was confirmed later by surgery. The left and right adrenal glands weighed 105 and 45 g, respectively. Hyper-reaction of the adrenal gland to a small change in plasma ACTH or "unknown factors" may cause not only the discrepancy between cortisol and ACTH response but also the development of autonomous nodules in the adrenal gland.
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PMID:Cushing's syndrome due to huge nodular adrenocortical hyperplasia with fluctuation of urinary 17-OHCS excretion. 262 Jun 63

As is obvious from the previous discussions, obesity is associated with a wide variety of changes in endocrine parameters (Table 1). Some of these changes, such as the reduction in SHBG without change in serum free testosterone levels, reflect merely laboratory abnormalities that may influence interpretation of diagnostic tests but have no important physiologic relevance. Other abnormalities have major clinical impact, such as hyperestrogenemia-endometrial carcinoma and hyperlipidemia-coronary artery disease. In some cases, endocrine changes in obesity are beneficial--that is, hyperestrogenemia leading to lower incidence of osteoporosis. In other cases, such as the profound suppression of growth hormone output in obesity, the physiologic relevance is unknown. Several endocrine changes in obesity, such as the impaired response of many hormones (growth hormone, prolactin, vasopressin, corticotropin) to insulin-induced hypoglycemia and elevated endorphin levels, suggest hypothalamic dysfunction. Furthermore, the failure of all of these abnormalities to be normalized after weight reduction raises the possibility of an underlying disorder leading to both endocrine dysfunction and obesity, rather than the endocrine dysfunction being simply a consequence of the obesity. Successful elucidation of the pathogenesis of obesity, which might then lead to much needed specific treatment modalities, may be advanced if we can solve some of these puzzles.
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PMID:Endocrine aspects of obesity. 264 1

Bilateral adrenalectomy (ADRX) in rats removes the source of two major stress-responsive hormones, corticosterone and epinephrine. To test how ADRX rats withstand stress, we performed the following experiments in adult male rats provided with indwelling femoral arterial and venous cannulae and either ADRX or sham-adrenalectomized (Sham) 3 days later and given 0.5% NaCl to drink. Five to 6 days after adrenal surgery the rats were studied after either a 15 ml/kg.5 min hemorrhage or after an overnight fast followed by insulin-induced hypoglycemia. In fed unstressed ADRX rats, basal mean arterial blood pressure was slightly decreased; heart rate was increased; blood volume, vasopressin, and oxytocin concentrations were not different from sham values; and renin and norepinephrine were significantly elevated. The recovery of arterial pressure after hemorrhage in the ADRX rats was similar to that in the sham group over a 5-h period; however, the responses of vasopressin and oxytocin were significantly greater, and those of renin and norepinephrine were markedly potentiated in the ADRX group. Heart rate recovered faster in the ADRX group and was elevated, compared to the sham value, for most of the 5-h period. Restitution of blood volume was attenuated in the ADRX group, although the restitution of plasma protein was not different between the groups. A significant difference in the change in plasma osmolality between groups after hemorrhage may account for the attenuated restitution of blood volume. After an overnight fast, which reduced blood volume in both groups of rats, the plasma renin concentration rose still further in ADRX rats; the differences in other measured variables observed between fed ADRX and sham groups remained the same. The insulin-induced 50% decrease in glucose caused minor effects on arterial blood pressure and heart rate and occasioned responses in renin and norepinephrine of similar magnitudes in the two groups. We conclude that in the absence of the adrenals, rats restore arterial pressure after hemorrhage remarkably well through potentiation of the responses of other vasoactive neural and hormonal systems. In these studies the marked potentiation of the renin response suggests that the renin-angiotensin system may be important in the maintenance of arterial blood pressure after reductions in blood volume.
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PMID:Potentiation of hormonal responses to hemorrhage and fasting, but not hypoglycemia in conscious adrenalectomized rats. 266 56

The diabetes insipidus which accompanies the DIDMOAD (Wolfram) syndrome is thought to be hypothalamic in origin, though no formal study of vasopressin secretion in the syndrome has been published, and some data in the literature suggest a renal tubular defect. We have studied vasopressin secretion in seven patients with the Wolfram/DIDMOAD syndrome during three dynamic stimuli: an osmotic stimulus (hypertonic saline infusion), hypoglycaemia (insulin tolerance test) and a baroregulatory stimulus (trimetaphan infusion). Hypertonic saline infusion demonstrated three patients to have complete and four to have partial hypothalamic diabetes insipidus; administration of (per nasal) desmopressin excluded nephrogenic diabetes insipidus in all seven patients. Insulin hypoglycaemia failed to stimulate vasopressin release, but trimetaphan-induced hypotension produced significant though subnormal rises in plasma vasopressin in three patients with partial diabetes insipidus, though it produced a negligible rise and no rise in plasma vasopressin in two patients with complete diabetes insipidus. The data suggest a much greater frequency of hypothalamic diabetes insipidus in the Wolfram/DIDMOAD syndrome than is reported, but did not identify nephrogenic diabetes insipidus. The absence of vasopressin responses to non-osmotic stimuli in patients with complete diabetes insipidus suggests global lack of vasopressin secreting neurones, rather than an isolated osmoreceptor defect or selective vasopressin secreting neuronal loss, as the lesion producing diabetes insipidus in the DIDMOAD syndrome.
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PMID:Vasopressin secretion in the DIDMOAD (Wolfram) syndrome. 268 31

With the development of sensitive and specific radio-immunoassays to measure the low circulating concentrations of vasopressin there has been a quantum leap in our understanding of the physiological processes involved in the regulation of its secretion. The results of Verney's pioneering studies in dogs led to the concept of 'osmoreceptors'. It is now appreciated that osmoregulation of vasopressin release is of principal importance in the maintenance of water balance. Functional characteristics of the osmoregulatory system have been defined clearly by independent laboratories, and more recently the physiological influences that can subtly alter this very finely controlled system have been described. Non-osmotic factors that release vasopressin have been recognized for many years. Secretion of vasopressin in response to haemodynamic influences has been characterized, and significant hypotension and/or hypovolaemia are potent stimuli to hormone release. Other non-osmotic factors--nausea/emesis, hypoglycaemia--may play important roles in disturbances of water balance. Vasopressin should not, however, be regarded as a stress hormone, since recent careful studies in a variety of species indicate that secretion is not enhanced following a series of different noxious stimuli.
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PMID:Regulation of vasopressin secretion. 269 40

We have investigated the importance of endogenous opioids in the differential control of neurohypophysial peptide secretion. The effect of the opioid antagonist naloxone on the vasopressin and oxytocin responses to insulin-induced hypoglycemia was studied in 14 male subjects. Either saline (N = 8) or naloxone (4 mg bolus + 6 mg/h, N = 6) was infused iv during the study. After 60 min infusion soluble insulin 0.15 U/kg was injected. Naloxone infusion for 60 min did not alter basal plasma AVP or OT levels. Insulin-induced hypoglycemia led to a significant rise in plasma AVP in both saline and naloxone-infused subjects (P less than 0.05), which was maximal 45 min after insulin. There was no significant difference in the plasma AVP response to hypoglycemia between the 2 groups. Saline-infused subjects did not show any change in plasma OT in response to hypoglycemia whilst during concurrent naloxone infusion there was a significant rise in OT from 1.9 +/- 0.4 pmol/l before insulin to 3.2 +/- 1.3 pmol/l at 45 min (P less than 0.05). We conclude that there is opioid-mediated inhibition of OT which prevents its release when AVP is secreted in response to insulin-induced hypoglycemia.
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PMID:Opioid-mediated inhibition of oxytocin during insulin-induced hypoglycemic stimulation of vasopressin in man. 283 96

Eight otherwise healthy insulin-dependent diabetic patients were subjected to controlled, symptomatic hypoglycaemia for 20 min (median glucose concentration 1.7 mmol/l, range 1.0-2.6 mmol/l). Concentrations of plasma adrenaline and plasma vasopressin were significantly increased, indicating normal counter-regulatory responses for these hormones. Plasma activities of the hepatic enzymes AST, ALT, LDH, GGT, and CK did not increase during or following the period of hypoglycaemia. Thus, abnormal plasma enzyme activities noted after clinical hypoglycaemia should be fully investigated, and not disregarded as due to the hypoglycaemic episode.
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PMID:A rise in the plasma activities of hepatic enzymes is not a common consequence of hypoglycaemia. 289 67

The changes in blood glucose, plasma oxytocin, plasma vasopressin, plasma atrial natriuretic peptide, serum osmolality, haematocrit and blood pressure were measured in response to acute insulin-induced hypoglycaemia in six normal male subjects. After the i.v. administration of insulin (0.15 U/kg), plasma concentrations of oxytocin and vasopressin increased rapidly in all subjects and were maximal 15 min after the acute hypoglycaemic reaction (R). Haematocrit increased at the time of the hypoglycaemic reaction, but there was no change in serum osmolality. Systolic blood pressure rose and diastolic blood pressure fell, but mean arterial blood pressure remained unchanged. No changes were demonstrated in plasma concentrations of atrial natriuretic peptide. The release of oxytocin and vasopressin in response to acute hypoglycaemia in man is probably caused by stimulation of the posterior pituitary gland via hypothalamic activation, and not by stimulation of osmoreceptors or baroreceptors.
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PMID:Plasma oxytocin, arginine vasopressin and atrial natriuretic peptide responses to insulin-induced hypoglycaemia in man. 295 4

The endocrine function of the thyroid and gonads has for long been investigated using the corresponding releasing hormones (TRH- and LHRH-test, respectively). The adrenal cortex has, up to now, been stimulated using insulin-induced hypoglycaemia or lysine-vasopressin and growth hormone stimulated using arginine. New diagnostic possibilities have arisen with the isolation of the corresponding releasing-hormones, CRF and GRF, and with the availability of these too for clinical use. Using the four above mentioned releasing-hormones in a global pituitary-stimulation-test, the secretion of ACTH, cortisol, STH, TSH, LH, FSH and prolactin hormones can now be examined together.
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PMID:[Global pituitary stimulation test with releasing hormones]. 298 36


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