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Query: UNIPROT:P01185 (
vasopressin
)
23,126
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Somatostatin (SRIF) receptors are expressed in the external granule cell layer of the rat cerebellum during early postnatal life. The aim of the present study was to investigate the distribution and biochemical characteristics of SRIF binding sites in the cerebellum of homozygous (
vasopressin
deficient) Brattleboro rats, which exhibit a selective impairment of their granule cell layer. This study has been conducted in 13-day-old rats by means of membrane-binding assay and autoradiography using [125I-Tyr0,DTrp8]S14 as a radioligand. In the cerebellum of homozygous Brattleboro rats, Scatchard plot analysis revealed the existence of a single class of SRIF receptors with similar Kd values as in Long-
Evans
or heterozygous Brattleboro rats (180-200 pM). Conversely, a marked reduction of the concentration of SRIF binding sites was observed in Brattleboro rats as compared to heterozygous or Long-
Evans
rats. In homozygous Brattleboro rats, autoradiographic studies revealed that the concentration of SRIF receptors was reduced in all lobules of the cerebellum as compared to Long-
Evans
. In addition, the magnitude of the decrease of receptor concentration was greater than the loss of granule cells observed in the homozygous Brattleboro rat. These results indicate that the expression of SRIF receptors by immature granule cells of the cerebellum is markedly reduced in Brattleboro rats. Whether the impairment of SRIF receptors in diabetes insipidus rats can directly be ascribed to
vasopressin
deficiency remains to be determined.
...
PMID:Expression of somatostatin receptors is impaired in the cerebellum of developing Brattleboro rats. 198 Aug 50
The analgesic effect of electrical stimulation of the hypothalamic paraventricular nucleus (PVN) was studied. Additionally, the involvement of
vasopressin
and opioid peptides in this process was examined by comparing
vasopressin
-deficient (Brattleboro) and Long-
Evans
rats and by administering the opiate antagonist naloxone. Rats were chronically implanted with a stimulating electrode in the parvocellular (PVN-Pc) and magnocellular (PVN-Mg) divisions of the PVN. At least 10 days after surgery, the analgesic effects of PVN stimulation were examined in lightly anesthetized rats, using the tail-flick method, and in unanesthetized rats, using the hot-plate test. PVN stimulation produced marked analgesia in both tests. Current threshold for analgesia was lower from PVN-Pc than from PVN-Mg. Threshold did not differ significantly between Brattleboro and Long-
Evans
rats and was not affected by naloxone administration. The results indicate that the PVN is part of the brain's pain inhibitory system, and show that the analgesia induced by PVN stimulation is not mediated by either
vasopressin
or opioid peptides.
...
PMID:Stimulation of the hypothalamic paraventricular nucleus produces analgesia not mediated by vasopressin or endogenous opioids. 198 39
The contribution of oxytocin to the maintenance of renal Na+ excretion in the Brattleboro rat has been examined in animals infused with hypotonic saline. Brattleboro rats exhibited hypernatraemia and hyperosmolality associated with greatly increased plasma concentrations of oxytocin by comparison with Long-
Evans
control rats. Neurohypophysectomy to remove the secretion of the remaining posterior pituitary peptide, oxytocin, led to greatly diminished rates of Na+ excretion in the Brattleboro rat. Oxytocin replacement to achieve plasma levels equivalent to those in intact Brattleboro rats produced a substantial and sustained natriuresis in the neurohypophysectomized animal. Oxytocin secretion evoked in response to saline infusion would thus appear to be effective in promoting renal Na+ excretion in the absence of
vasopressin
in the Brattleboro rat.
...
PMID:Influence of oxytocin on sodium excretion in the anaesthetized Brattleboro rat. 203 Mar 28
1. Measurements of changes in renal, mesenteric and hindquarters haemodynamics or cardiac haemodynamics in response to i.v. bolus doses of arginine vasopressin (AVP) or lysine
vasopressin
(LVP, 0.7 and 7.0 pmol) were made in conscious, chronically-instrumented Long
Evans
rats. 2. In some experiments AVP and LVP were administered during an infusion of NG-nitro-L-arginine methyl ester (L-NAME; 1.0 or 0.3 mg kg-1 h-1) to determine whether or not inhibition of nitric oxide production influenced the cardiovascular effects of the peptides. In other experiments, indomethacin (bolus dose of 5 mg kg-1 followed by infusion at 5 mg kg-1 h-1) was given to determine the possible involvement of cyclo-oxygenase products in the responses to AVP and LVP. 3. Under control conditions, the lower dose of LVP had significantly greater effects than AVP on heart rate, mean arterial blood pressure, renal, mesenteric and hindquarters conductances, total peripheral conductance, cardiac index, peak aortic flow and +dF/dtmax. The higher dose of LVP had significantly greater effects than AVP on all variables (i.e. including stroke index and central venous pressure). 4. In the presence of L-NAME (1 mg kg-1 h-1) there was a sustained increase in mean arterial blood pressure (+23 +/- 3 mmHg) and reductions in mesenteric (-38 +/- 4%) and hindquarters (-30 +/- 6%) vascular conductances. Under these conditions the difference in the pressor effects of AVP and LVP was abolished, but their differential effects on regional and cardiac haemodynamics persisted. This dose of L-NAME did not change cardiac baroreflex sensitivity. 5. During infusion of L-NAME at a lower rate (0.3mgkg-th-1), baseline cardiovascular status was unchanged and regional haemodynamic effects of AVP and LVP were enhanced, but the differences in the regional vasoconstrictor responses to the two peptides persisted. 6. Indomethacin (5 mg kg-1 bolus, then 5 mg kg- 'h-1 infusion) augmented the renal vasoconstrictor responses to AVP and LVP, but abolished the difference in the hindquarters vasoconstrictor responses to the two peptides. However, the differences in the pressor and the renal and mesenteric vasoconstrictor effects of AVP and LVP still occurred in the presence of indomethacin. 7. The results indicate that AVP normally has lesser cardiovascular effects than LVP but this difference does not seem to be due to more effective stimulation of nitric oxide-mediated or cyclo-oxygenase-dependent vasodilator mechanisms by AVP than LVP.
...
PMID:Effects of NG-nitro-L-arginine methyl ester or indomethacin on differential regional and cardiac haemodynamic actions of arginine vasopressin and lysine vasopressin in conscious rats. 204 32
The effects of subcutaneous injections of
vasopressin
in
vasopressin
-deficient (Brattleboro or DI) rats were observed during nonstress (habituation) and stress (food-restriction) conditions as compared to other rats. Four groups of animals were employed: 1) Long-
Evans
(LE) rats that were food restricted with no injections (normal control animals), 2) DI rats that were food restricted with no injections, 3) DI rats injected with
vasopressin
, and 4) DI rats injected with peanut oil (vehicle). The parameters studied were: body weight, food intake, water intake, and gastric ulcer formation. With respect to body weight, water intake, and ulcer formation, two sets of animals emerged. The
vasopressin
-injected DI rats resembled the LE control rats, whereas the peanut oil-injected DI rats were similar to the DI rats with no injections. The former set of animals showed a higher body weight, reduced water intake, and fewer gastric ulcers than the latter set of animals. Thus the
vasopressin
-injected DI rats and the LE control rats could cope with the stress of food restriction, but the peanut oil-injected DI rats and the DI rats with no injections could not.
...
PMID:Effects of vasopressin replacement during food-restriction stress. 206 79
Despite the great impairment in water balance occurring in the Brattleboro rat, homozygous for diabetes insipidus and lacking hypothalamic
arginine-vasopressin
, fed a normal sodium diet, the metabolic effects of a chronic sodium deprivation were similar in the Brattleboro rat and in the Long-
Evans
rat used as control. Concomitantly, whilst the plasma and adrenal concentrations of aldosterone were two fold lower in the Brattleboro rat than in the Long-
Evans
rat fed a normal diet, after ten days of sodium restriction they became similar in the two groups of rats; sodium deprivation greatly increased aldosterone production in the same order of magnitude both in the Brattleboro rat and in the Long-
Evans
rat. It is suggested that chronic sodium depletion might have, in the Brattleboro rat, either suppressed the cause of the reduced aldosterone secretion or induced mechanisms which have offset it.
...
PMID:Effect of sodium deprivation on plasma and adrenal concentrations of aldosterone and corticosterone in the Brattleboro homozygous rat. 208 66
Spontaneous manipulator and locomotor activities, food and fluid intake have been recorded from rats suffering from a genetic lack of central
vasopressin
(VP) synthesis (Brattleboro strain, DI), their heterozygous litter mates (HZ) or Long
Evans
(LE) rats. The daily patterns of activities did not differ, except for their drinking behavior. This was mainly associated with food intake during the dark period with LE rats but was distributed equally during light and dark periods with DI rats. HZ rats showed a behavioral heterogeneity, some of them following the daily pattern of LE rats, and others, that of DI rats. The daily feeding pattern was identical in the three genotypes but the selection between two isocaloric contrasted diets was different. When they were fed ad lib, HZ and DI rats consumed less carbohydrate than LE rats, the protein intake being unchanged. On the contrary, when the DI rats were only fed during the dark period, they ate more carbohydrate than LE rats. The peripheral infusion of a V2 AVP agonist (dDAVP) restored a normal hydric balance in DI rats but failed to modify the diet selection. These data show that in the rats, the lack of central VP synthesis disturbs both the selection of diets and the efficiency of the satiety signals. These disturbances were unchanged by the peripheral VP treatment which suggested the direct involvement of the central release of the neuropeptide.
...
PMID:Ingestive behaviors of the rat deficient in vasopressin synthesis (Brattleboro strain). Effect of chronic treatment by dDAVP. 208 12
1. Conscious Long
Evans
rats, chronically instrumented for cardiovascular measurements, were challenged with i.v. bolus doses of glyceryl trinitrate (40 nmol kg-1), acetylcholine (1.2 nmol kg-1), bradykinin (3.2 nmol kg-1), or endothelin-1 (0.25 nmol kg-1). Under control conditions these doses produced similar falls in mean arterial blood pressure (glyceryl trinitrate, -20 +/- 3 mmHg; acetylcholine, -24 +/- 2 mmHg: bradykinin, -21 +/- 3 mmHg; endothelin-1, -25 +/- 3 mmHg), associated with renal, mesenteric and hindquarters vasodilatations (except for endothelin-1 which caused mesenteric vasoconstriction). 2. In the presence of NG-nitro-L-arginine methyl ester (L-NAME, 10 mgkg-1), a potent inhibitor of nitric oxide biosynthesis and endothelium-dependent vasorelaxation in vitro, the hypotensive responses to glyceryl trinitrate, acetylcholine, and endothelin-1 were increased, although that to bradykinin was not. However, comparing the differences between the response to glyceryl trinitrate and that to any other agonist in the absence and presence of L-NAME showed that there were relative attenuations of the hypotensive responses to bradykinin and endothelin-1, but not to acetylcholine, in the presence of L-NAME. 3. This comparative analysis showed that the renal and hindquarters vasodilator responses to bradykinin and endothelin-1 were attenuated in the presence of L-NAME, but the renal, mesenteric and hindquarters vasodilator responses to acetylcholine were not. However, when L-NAME was administered in the presence of pentolinium, captopril and the
vasopressin
V1-receptor antagonist, d(CH2)5[Tyr-(Et)]DAVP, (to abolish baroreflex and neurohumoral mechanisms), there was attenuation of the renal and mesenteric vasodilator effects of acetylcholine relative to those seen with glyceryl trinitrate. Under those conditions only the renal vasodilator effects of bradykinin and endothelin-1 were attenuated. 4. In separate experiments in conscious Long
Evans
rats, direct measurement of cardiac haemodynamics showed that the hypotensive responses to glyceryl trinitrate, acetylcholine, bradykinin and endothelin-l were entirely attributable to rises in total peripheral conductance since both in the absence and presence of L-NAME there were no reductions in cardiac index in response to these substances. 5. The results indicate that measurement of systemic arterial blood pressure alone in conscious rats does not permit reliable quantitation of the influence of L-NAME on regional vasodilator responses to glyceryl trinitrate, acetylcholine, bradykinin or endothelin-1. Furthermore, these substances exert effects in different vascular beds that may be differentially influenced by baroreflex mechanisms, neurohumoral mechanisms, or both. Moreover, except in the case of the renal vasodilator response to endothelin-1 (which was abolished in the presence of L-NAME), even when L-NAME caused attenuation of the vasodilator effects of acetylcholine or bradykinin (relative to glyceryl trinitrate), substantial responses remained. It is feasible that such responses in vivo are nitric oxide-independent.
...
PMID:Regional and cardiac haemodynamic responses to glyceryl trinitrate, acetylcholine, bradykinin and endothelin-1 in conscious rats: effects of NG-nitro-L-arginine methyl ester. 212 52
The diabetogenic agent streptozotocin (STZ) was injected intraperitoneally in Long-
Evans
and arginine vasopressin (AVP)-deficient Brattleboro rats. Twenty-eight days later both strains had a bradycardia and systolic hypotension; STZ-treated Brattleboro rats also had diastolic hypotension. The
vasopressin
(V1-receptor) antagonist, d(CH2)5[Tyr(Et)]DAVP, had no effect on resting blood pressure (BP) or heart rate (HR) in either strain of rat, indicating the relative maintenance of diastolic BP in STZ-treated Long-
Evans
rats was not dependent on acute vascular actions of AVP. Captopril caused a modest hypotension in all groups of rats, indicating that BP was not differentially dependent on the renin-angiotensin system in the different groups. In the presence of captopril and the ganglion blocker, pentolinium tartrate, the AVP-mediated recovery in BP was impaired in STZ-treated Long-
Evans
rats. During administration of d(CH2)5[Tyr(Et)]DAVP and pentolinium, the angiotensin II (ANG II)-mediated BP recovery was smaller in both groups of STZ-treated rats, indicating that this abnormality was not likely to be caused by inhibition of renin release by AVP. The abnormalities in ANG II- and AVP-mediated recovery were prevented by insulin treatment.
...
PMID:Blood pressure in streptozotocin-treated Brattleboro and Long-Evans rats. 213 47
1. The regional haemodynamic effects of bolus doses (4 and 40 pmol) and infusions (12 and 120 pmol h-1) of endothelin-1 and endothelin-3 were assessed in conscious, Long
Evans
and Brattleboro (i.e.
vasopressin
-deficient) rats, chronically-instrumented with pulsed Doppler flow probes. 2. In both strains of rat the lower bolus dose of endothelin-1 caused only a slight pressor effect, but there were marked renal and mesenteric vasoconstrictions and hindquarters vasodilatation. 3. The lower bolus dose of endothelin-3 did not affect blood pressure significantly, although the changes in regional haemodynamics were qualitatively similar to those seen following endothelin-1 in Long
Evans
and Brattleboro rats. 4. The higher dose of endothelin-1 caused an initial hypotension accompanied by substantial hindquarters vasodilatations in Long
Evans
and Brattleboro rats. Subsequently, in both strains, there was a rise in blood pressure accompanied by renal, mesenteric and hindquarters vasoconstrictions. 5. The higher bolus dose of endothelin-3 caused initial hypotension and hindquarters vasodilatation similar to those seen with endothelin-1. However, the subsequent pressor effect was less with endothelin-3, as was the renal vasoconstriction, and it did not cause any increase in hindquarters vascular resistance. 6. Infusion of endothelin-1 at the lower rate (12 pmol h-1) caused renal and mesenteric vasoconstrictions in both strains of rat, whereas endothelin-3 at this rate caused only mesenteric vasoconstriction. 7. Infusion of endothelin-1 at the higher rate (120 pmol h-1) caused progressive hypertension and vasoconstrictions in all three vascular beds studied; these were similar in both strains of rat. Endothelin-3 had a smaller pressor effect and a lesser constrictor action on the renal and mesenteric vascular beds; it did not constrict the hindquarters vascular bed. 8. These results show, that in conscious Long
Evans
and Brattleboro rats, the initial depressor effects of the higher bolus doses of endothelin-1 and -3 were similar, and, hence, not influenced by the absence of endogenous
vasopressin
. Endothelin-1 and -3 appear equipotent in their initial hyperaemic vasodilator effects in the hindquarters vasculature in both strains, making it unlikely that this effect is dependent on the release of atrial natriuretic peptide (ANP), since ANP does not cause significant increases in hindquarters blood flow in Brattleboro rats. The greater delayed pressor effect of endothelin-1 is associated with its more marked vasoconstrictor effects on renal and mesenteric vascular beds and is accentuated, relative to endothelin-3, by the lack of a constrictor effect of endothelin-3 in the hindquarters vasculature.
...
PMID:Regional haemodynamic effects of endothelin-1 and endothelin-3 in conscious Long Evans and Brattleboro rats. 213 84
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