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Query: UNIPROT:P01185 (
vasopressin
)
23,126
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We contrasted the renal effects of
vasopressin
in Brattleboro rats with and without pretreatment with aprotinin (20,000 KIU kg-1). In both treatment groups,
vasopressin
injected at 3 mU kg-1 sec caused in conscious rats elevation of urine osmolality and reduction of urine flow and urinary excretion of total solutes. However, these effects of
vasopressin
were significantly greater in aprotinin pretreated rats than in rats without aprotinin treatment. In ketamine-pentobarbital-anesthetized rats without aprotinin pretreatment,
vasopressin
infused at 2 mU kg-1 hr-1 elevated urinary kinin excretion but did not affect urine flow rate or osmolality; in contrast, in aprotinin-pretreated rats, the same dose of
vasopressin
did not increase urinary kinins but caused elevation of urinary osmolality and reduction of urine flow, solute excretion, and glomerular filtration rate. Aprotinin pretreatment in anesthetized rats also blunted the rise in kinin excretion elicited by
vasopressin
at a higher dosage, 5 mU kg-1 hr-1, but did not potentiate the
vasopressin
-induced
antidiuresis
. We conclude that aprotinin facilitates the expression of the antidiuretic effect of
vasopressin
at a low, but not at a high dosage. This effect of aprotinin may be a consequence of: renal kallikrein inhibition which prevents augmentation of renal kinins in response to increased
vasopressin
levels, or other unrecognized properties of aprotinin.
...
PMID:Augmentation by aprotinin of the renal response to vasopressin. 243 37
Studies were carried out to evaluate adaptive responses to water retention in an experimental model of the syndrome of inappropriate
antidiuresis
(SIAD). Hyponatraemia was induced by continuous s.c. infusions of the antidiuretic
vasopressin
analogue 1-deamino-[8-D-arginine]-
vasopressin
in rats ingesting a 5% (w/v) dextrose solution. After 48 h of sustained decreases in the plasma concentration of Na+ to 23-25% of normal levels, all body fluid compartments were significantly expanded: plasma volume estimated by changes in plasma protein concentration was increased by 26%, extracellular fluid volume estimated by 22Na volume of distribution was increased by 24%, and total body water estimated by 3H2O volume of distribution was increased by 16%. Despite marked increases in all body fluid compartment volumes, mean arterial blood pressure was only modestly increased to 110 +/- 2 mmHg in conscious hyponatraemic rats. Consistent with the sustained volume expansion, both basal and stimulated plasma renin activities were significantly suppressed in the hyponatraemic rats. Plasma
vasopressin
levels were similarly suppressed, and the hyponatraemic rats showed a striking absence of endogenous
vasopressin
secretion in response to marked intravascular volume depletion (15-45%) produced by s.c. administration of polyethylene glycol. Plasma concentrations of atrial natriuretic peptide were initially stimulated four- to fivefold above basal levels in response to the water-induced volume expansion, but by 48 h fell to ranges not significantly different from basal unstimulated levels, despite continued plasma and extracellular fluid volume expansion at that time. These results illustrate that multiple haemodynamic and hormonal adaptive responses occur with sustained dilutional hyponatraemia in rats, and suggests that these can be of sufficient magnitude to allow continued water retention without necessarily provoking either escape from
antidiuresis
or continued natriuresis. In contrast with previous studies in experimental animals in which hyponatraemia was maintained by continuous forced administration of hypotonic fluid, rats in this model reached a steady state with characteristics resembling many of those observed clinically in patients with SIAD.
...
PMID:Adaptive responses to sustained volume expansion in hyponatraemic rats. 252 41
1. Subcutaneous injection of the kappa-opioid agonist U50,488 into conscious, saline-loaded rats was associated with a diuresis, antinatriuresis and antikaliuresis which lasted for up to 3 h. Plasma renin activity and corticosterone levels were elevated but plasma
vasopressin
(AVP) and aldosterone levels were unaltered in similarly treated rats. 2. U50,488 administration to adrenal demeddulated rats was not associated with a diuresis but produced an antinatriuresis, though sodium excretion rates were higher in demedullated than in sham-operated animals. Plasma AVP and corticosterone levels were not affected by demeddulation or subsequent U50,488 treatment. Sham-operated, U50-488-treated rats showed the expected increase in plasma corticosterone levels. 3. U50,488 administration resulted in an
antidiuresis
and an antinatriuresis in AVP-deficient Brattleboro DI rats. 4. When coupled with fasting stress U50,488 administration resulted in similar but attenuated renal responses compared with those observed in unfasted rats. Basal plasma corticosterone levels were elevated in fasted animals and were further increased by U50,488. 5. Both water and electrolyte handling by the kidney are altered by U50,488. The diuretic effects of U50,488 were reversed by adrenal demedullation and in the absence of endogenous AVP, but the antinatriuretic actions were not altered, suggesting that the effects upon renal water and electrolyte excretion may be mediated by separate mechanisms.
...
PMID:Kappa-opioid-induced changes in renal water and electrolyte management and endocrine secretion. 254 85
The modulatory effects of opioids on urine production in adult rats have been well-documented. We report here the first investigation of the effects of these agents on urination in neonatal rats. The kappa-agonists U50,488H (1,10 mg kg-1) and (+)-tifluadom (10 mg kg-1) produced an increase in urine output in 10-day old pups whereas the (-)-isomer of tifluadom was ineffective in this model. The diuretic effects of the highest dose of U50,488H were attenuated by a 10 but not a 1 mg kg-1 dose of the opioid antagonist naltrexone. These findings suggest that kappa-agonists, as in adult animals, produce diuresis in neonates by activity at kappa-opioid receptors and also confirm the stereoselective nature of the response. The increase in urination produced by U50,488H (10 mg kg-1) was also reduced by the alpha-adrenoceptor antagonist phentolamine (1 mg kg -1), an observation which supports the hypothesis that kappa-agonists--in addition to their well-established inhibitory effects on the release of
antidiuretic hormone
--may increase urination via an adrenergic mechanism at the level of the adrenal medulla. The mu-opioid agonist morphine (0.1-10 mg kg-1), in contrast to its observed effects in older animals, did not produce
antidiuresis
in either normally-hydrated or water-loaded 10-day old rat pups. The results of this study therefore show that the stimulatory effects of kappa-agonists on urine production appear to be fully-functional at 10-days but the inhibitory effects of opioids on urination lag behind in development.
...
PMID:Effects of opioid agonists on urine production in neonatal rats. 256 75
Renal function has been studied by the clearance (cl.) method during hypotonic polyuria--four 15-min cl. periods--and successive
antidiuresis
--two 60-min cl. periods (A1, A2)--induced by lysine-8-
vasopressin
(LVP), 5 mU in bolus followed by infusion at a rate of 0.04 mU/min. The endogenous creatinine cl. (Cc) and the osmotic cls. (Cosm, CH2O) were determined by the usual methods as well as the absolute and fractional urinary excretions of water, sodium, chloride and potassium. The urinary concentrations of PGE2, 6-keto-PGF1 alpha and TxB2 were determined by the RIA method. This study protocol has been applied to 28 healthy women either in normal potassium balance (N, n = 14) or after potassium depletion (KD) induced by low potassium dietary intake (less than or equal to 10 meq/d) plus natriuretic treatment according to two different time patterns: two KD groups were obtained with potassium cumulative deficit of 160 +/- 43 (D2, n = 8) and 198 +/- 22 meq (D3, n = 6). The early % effects of LVP, i.e. (A1-P)% of P (mean polyuria), were significantly different only in D3 as compared to N. Precisely, the LVP-effect to reduce Cc was blunted; moreover a LVP-effect to reduce renal sodium and chloride fractional excretions and a tendentiously enhanced LVP-effect to reduce water fractional excretion were observed. These tubular effects are likely related to the inhibited renal synthesis of prostanoids in the D3 group.
...
PMID:[Renal function in experimental potassium depletion. I. Effects of lysine-8-vasopressin in hypotonic polyuria]. 262 31
Renal function has been studied by the clearance (cl.) method during hypotonic polyuria--four 15-min cl. periods--and successive
antidiuresis
--two 60-min cl. periods (A1, A2)--induced by lysine-8-
vasopressin
(LVP), 5 mU in bolus followed by infusion at a rate of 0.04 mU/min. The endogenous creatinine cl. (Cc) and the osmotic cls. (Cosm, CH2O) were determined by the usual methods as well as the absolute and fractional urinary excretions of water, sodium, chloride and potassium. The urinary concentrations of PGE2, 6-keto-PGF1 alpha and TxB2 were determined by the RIA method. This study protocol has been applied to 20 healthy women submitted to paired functional explorations in both the absence and presence of indomethacin (100 mg i.m.); the drug effects have been evaluated in both normal potassium balance (N2, n = 6) and in two groups of potassium depletion (KD) with potassium cumulative deficit of 160 +/- 43 (D2, n = 8) and 198 +/- 22 meq (D3, n = 6), respectively. As regards the early % effects of LVP, i.e. (A1-P)% of P (mean polyuria), the inhibition of prostanoid synthesis with indomethacin produced significant changes: 1) an enhanced reduction in renal chloride excretion in all experimental groups; 2) a reduction in renal sodium and chloride fractional excretions in both KD groups; 3) an enhanced antidiuretic effect in D3 only, i.e. in the experimental condition with inhibition of prostanoid renal synthesis present during the control study.
...
PMID:[Renal function in experimental potassium depletion. II. Indomethacin and effects of lysine-8-vasopressin in hypotonic polyuria]. 262 32
Ten male healthy volunteers were studied in order to determine whether the synthetic somatostatin analogue Sandostatin (SMS 201-995) has effects similar to those of natural somatostatin on renal water and electrolyte excretion. The study was carried out in three separate placebo-controlled randomized double-blind cross-over trials. The subjects received single sc injections of 100 micrograms Sandostatin and placebo under conditions of mild diuresis (trial 1), water load with enhanced diuresis (trial 2), and water load with exogenous lysin-
vasopressin
(5 IU sc) induced
antidiuresis
(trial 3). The following parameters were measured: urine flow rate, serum and urine osmolalities, osmolar clearance, free water and creatinine clearances, excretion rates of sodium, potassium, calcium, chloride, and phosphate, and immunoreactive insulin. A marked antidiuretic effect was observed within 2 h after dosing in all three trials. Urine flow rates were reduced by 45% in trial 1 and by 29 and 31% in trials 2 and 3, respectively (all P less than 0.05). There were no differences in effects on serum and urine osmolalities between Sandostatin and placebo. Osmolar clearance was significantly reduced in trial 1 (P less than 0.01). Free water clearance significantly decreased only in trial 2 (P less than 0.05). Sodium excretion decreased by 49, 48 and 67%, respectively, the differences being significant in trials 1 and 3 (P less than 0.05). Calcium excretion decreased by 66, 70 and 54% (all P less than 0.001). Chloride excretion decreased by 28, 22 and 44%, the differences being significant in trials 2 and 3 (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Antidiuretic effect of Sandostatin (SMS 201-995) in healthy volunteers. 265 54
Microinjection of the muscarinic agonist oxotremorine into the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei which contain cell bodies of vasopressinergic neurons induced potent antidiuretic effects in water-loaded and ethanol-anesthetized rats. The effects included both decreases in urine outflow and increases in urine osmotic pressure. However, no significant changes in various visceral functions other than
antidiuresis
such as mean blood pressure, heart rate, respiration rate and rectal temperature were observed when oxotremorine was microinjected into the SON. Only a slight change in mean blood pressure (approx. 10 mmHg decrease) was observed by the microinjection into the PVN. Intravenous preinjection of a
vasopressin
(AVP) V1 V2 antagonist that has one of the most potent V2 (antidiuretic)-antagonist activities, d(CH2)5-D-Tyr(Et)VAVP, inhibited nearly completely the antidiuretic effects induced by the microinjection of oxotremorine. The results demonstrated that oxotremorine stimulated muscarinic receptors in the hypothalamic SON and PVN, released AVP and induced an antidiuretic effect through AVP-receptors in the kidney.
...
PMID:Effect of vasopressin antagonist on antidiuresis by oxotremorine microinjected into the hypothalamic supraoptic and paraventricular nuclei in a water-loaded and ethanol-anesthetized rat. 274 38
The renal function was studied by clearance (cl.) method during hypotonic polyuria (oral water load followed by 5% dextrose solution infusion) and successive relative
antidiuresis
induced by lysine-8-
vasopressin
(LVP) administration (5 microU in bolo followed by continuous infusion at a rate of 0.04 microU/min). Four 15 min and two 60 min clearance (cl.) periods were performed during hypotonic polyuria and
antidiuresis
, respectively. Glomerular filtration rate was estimated by creatinine cl.; the osmotic cl. (Cosm, CH2O), the absolute and fractional excretions of water, sodium, potassium and chloride were determined by usual methods. The urinary PGE2, 6-keto-PGF1 alpha and TxB2 concentrations were determined by RIA method. Fourteen healthy women submitted to a normal sodium and potassium daily intake were studied; in 6 of them paired studies in absence and in presence of indomethacin (100 mg, i.m.), respectively, were performed. LVP induced a significant reduction of creatinine cl., urinary flow rate and of prostanoid excretion. In hypotonic polyuria, indomethacin significantly reduced the creatinine cl. and the diuretic response to the water load; moreover the urinary PGE2 and 6-keto-PGF1 alpha excretions were significantly lower (85.6 +/- 1.9% and 37.7 +/- 3.2%) while the reduction of urinary TxB2 excretion was not significant (34.4 +/- 13%). Indomethacin did not affect significantly the LVP renal effects in normal potassium balance.
...
PMID:[Further research on the role of prostanoids in controlling renal function in humans in normal potassium balance and acute experimental potassium depletion. I: Studies of normal potassium balance. Effects of indomethacin]. 275 82
The renal function was evaluated by clearance (cl.) method during hypotonic polyuria and successive relative
antidiuresis
induced by lysine-8-
vasopressin
(LVP) administration. Four 15 min and two 60 min cl. periods were performed during hypotonic polyuria and
antidiuresis
, respectively. Glomerular filtration rate was estimated by creatinine cl.; the osmotic cl. (Cosm'CH2O), the absolute and fractional excretions of water, sodium, potassium and chloride were determined by usual methods. The urinary PGE2, 6-keto-(-)PGF1 alpha and TxB2 concentrations were determined by RIA method. The study protocol was applied on 22 healthy women in acute potassium depletion obtained by natriuretic treatment combined with replacement on quantitative basis of net salt and water urinary losses either in normal potassium diet intake (50 meq/d) or in a low one (less than or equal to 10 meq/d). In Group D3 (n = 6) in the presence of a greater potassium cumulative deficit (198.4 +/- 22.2 meq), as compared to normal potassium balance, a significant reduction of kaliemia and a significant increase of PRA were present. During hypotonic poliuria, besides a marked renal potassium conservation, a significant decrease of creatinine cl., fractional chloride reabsorption (apparently at the diluting segments) and of urinary 6KPGF and TxB2 excretions, were observed. Urinary PGE2 excretion was n.s. reduced.
...
PMID:[Further research on the role of prostanoids in controlling renal function in humans in normal potassium balance and acute experimental potassium depletion. II: Studies of potassium depletion]. 275 83
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