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Query: UNIPROT:P01185 (
vasopressin
)
23,126
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Based on previous studies demonstrating coexistence of
NADPH-diaphorase
(ND) and
vasopressin
(VP) in the rat hypothalamus. ND histochemistry and vasotocin (VT) immunocytochemistry have been combined in order to study the distribution of both markers in the hypothalamus of the Japanese quail (Coturnix japonica) and chicken (Gallus domesticus). No coexistence was found, however, close anatomical relationships between ND-positive and VT-immunoreactive elements were observed in specific preoptic and hypothalamic locations. These findings indicate interspecies differences in the expression of ND and the
antidiuretic hormone
with functional implications in osmoregulation.
...
PMID:Absence of coexistence between NADPH-diaphorase and antidiuretic hormone in the hypothalamus of two galliforms: Japanese quail (Coturnix japonica) and chicken (Gallus domesticus). 889 81
1. Cytomegalovirus (CMV) is a major pathogen in immunocompromised individuals and may participate in the pathogenesis of atherosclerosis in the general population. We evaluated whether CMV-infection alters the function of arterial smooth muscle. 2. Blood pressure (BP) and arterial reactivity were recorded in immunosuppressed rats that had been infected with CMV (10(5) plaque forming units i.p.). Furthermore, the reactivity of isolated arteries was compared between CMV-infected rats and rats injected with bacterial endotoxin (LPS). 3. Initially resting BP and heart rate (HR) were not modified in CMV-infected rats, but baroreflex control of HR was impaired. By the eighth day post-CMV, BP dropped precipitously and could no longer be raised by phenylephrine (PHE). 4. In mesenteric resistance arteries, isolated at this stage from CMV-infected rats, contractile responses to nerve stimulation, noradrenaline, PHE and 5-hydroxytryptamine (5-HT) were virtually absent while those to high potassium and
vasopressin
(AVP) were not modified. In aortae of CMV-infected rats, responses to 5-HT and AVP were impaired while those to PHE or potassium were hardly affected. Reduced contractile responses could not be restored by NG-nitro-L-arginine methyl ester (L-NAME). 5. Continuous treatment of CMV-infected rats with prazosin (0.1 mg kg-1 day-1) prevented blood pressure lowering and resistance artery changes. 6. Observations in arteries of LPS-treated rats (5-10 mg kg-1, i.p.) differed markedly from those in vessels of CMV-infected animals. The contractile reactivity of their mesenteric resistance arteries was not altered while in their aortae, responses to PHE, 5-HT and AVP were reduced. With the exception of the AVP responses, this was more pronounced in the presence of 1-arginine and reversed by L-NAME. 7. These findings indicate that CMV-infection results in a reduction of resistance artery reactivity and hypotonia. This seems not to involve cytokine-mediated induction of
NO synthase
in the vascular wall but may be due to alterations of excitation-contraction coupling in arterial smooth muscle in response to increased sympathetic nervous input.
...
PMID:Impaired arterial reactivity following cytomegalovirus infection in the immunosuppressed rat. 890 36
1. The present study was performed to characterize the tachyphylaxis of rat aortae to
vasopressin
. Isometric tension generated by rat thoracic aorta sliced in 4 mm rings, was recorded. 2. Tension generated by intact rings increased with cumulative additions of
vasopressin
up to 10 nM (1.51 +/- 0.15 g). After this concentration, most rings lost their tension and relaxed to 1.09 +/- 0.17 g (P < 0.001) despite further addition of
vasopressin
. This tachyphylaxis was not observed in endothelium-denuded rings (from 2.87 +/- 0.12 g to 2.68 +/- 0.17 g). 3. Repeated administrations of supramaximal concentration (100 nM) of
vasopressin
confirmed an enhanced desensitization in intact rings, compared to endothelium-denuded rings. No desensitization to phenylephrine was observed in intact or in endothelium-denuded rings. 4. Dose-response curves to a V1 receptor agonist, [Phe2, Ile3, Orn8]-
vasopressin
, and to a V2 receptor agonist, [deamino-Cys1,D-Arg8]-
vasopressin
, were performed in intact preparations. An increase in tension, followed by a desensitization was observed with the V1 receptor agonist. In contrast, the V2 receptor agonist did not induce any response. 5. Pretreatment of intact aortic rings with the cyclo-oxygenase inhibitor, diclofenac (1 microM), did not prevent the desensitization to
vasopressin
. In contrast,
NO synthase
inhibition with NG-nitro-L-arginine (30 microM) resulted in an attenuated desensitization to
vasopressin
in intact rings (from 2.46 +/- 0.17 to 2.25 +/- 0.22 g, NS). 6. To confirm the involvement of NO, endothelium-denuded rings were pretreated with sodium nitroprusside (SNP). At a concentration of 10 nM, SNP induced a desensitization to
vasopressin
comparable with that observed in intact rings. 7. Pretreatment of endothelium-denuded rings with 8-bromo-cyclic GMP (100 microM) reduced maximum contraction to
vasopressin
without producing any desensitization. In contrast, guanylate cyclase inhibition with either LY 83,583 (10 microM) or methylene blue (10 microM) blocked completely the desensitization of intact rings to
vasopressin
. 8. The results suggest that the endothelium-dependent tachyphylaxis to
vasopressin
is due to rapid desensitization and is mediated by NO. However, it is unclear whether this effect of NO involves cyclic GMP.
...
PMID:Endothelium-dependent and NO-mediated desensitization to vasopressin in rat aorta. 892 38
We investigated the chemical and anatomical features of
nitric oxide synthase
(
NOS
)-containing neurons in the paraventricular and supraoptic nuclei in the rat hypothalamus using combinations of enzyme histochemistry, in situ hybridization and immuno-histochemistry. Neurons expressing
NOS
mRNA completely overlapped with
NADPH-diaphorase
-positive neurons. Topographical distribution of
NOS
was segregated from that of CRF-containing parvicellular neurons in the posterior paraventricular nucleus but overlapped with that of magnocellular neurons. In the paraventricular nucleus, 70% of oxytocin neurons contained
NOS
, which corresponded to one half of
NOS
neurons. About one third of
vasopressin
-immunoreactive neurons were
NADPH-diaphorase
-positive and the same proportion of
NADPH-diaphorase
-positive neurons were
vasopressin
-immunoreactive. In the supraoptic nucleus, 50% of oxytocin neurons were
NADPH-diaphorase
-positive, which corresponded to 40% of
NOS
neurons. About 25% of
vasopressin
neurons were
NADPH-diaphorase
-positive, and 30% of
NADPH-diaphorase
-positive neurons were
vasopressin
-immunoreactive. When
NADPH-diaphorase
histochemistry was performed first, subsequent immunostaining was markedly perturbed. Using fluoro-gold as a retrograde tracer, 4% of
NADPH-diaphorase
-positive neurons were shown to contribute to the descending projection to the spinal cord. About 40%-50% of
NADPH-diaphorase
-positive neurons exhibited Fos immunoreactivity after injection of lipopolysaccharide or hypertonic saline, while only 10%-15% of these neurons expressed Fos in response to immobilization or pain. Endogenous NO may be involved in the regulation of magnocellular functions, especially when the internal environment is disturbed.
...
PMID:Nitric oxide synthase-containing magnocellular neurons of the rat hypothalamus synthesize oxytocin and vasopressin and express Fos following stress stimuli. 895 94
The renal vascular effects of [Arg8]
vasopressin
(
vasopressin
) were investigated in the isolated perfused rat kidney. Vasopressin (0.01-3 nM) elicited a dose-dependent vasoconstriction in kidneys from Sprague Dawley rats, with a EC50 value of 0.206 +/- 0.044 nM. Inhibition of
nitric oxide synthase
by N omega-nitro-L-arginine (100 microM) shifted the
vasopressin
-induced vasoconstrictor response curve to the left. Inhibition of cyclooxygenase by indomethacin (10 or 30 microM) blunted the constriction induced by low concentrations of the peptide. Vasopressin, like angiotensin II but not noradrenaline, induced tachyphylaxis, SR 49059 ((2S)1-[(2R,3S)-5-chloro-3-(2-chlorophenyl)-1-(3,4-dimethoxybenzene- sulfonyl)-3-hydroxy-2,3-dihydro-1H-indole-2-carbonyl]-pyrrolidine-2- carboxamide) (1-30 nM), a new potent and selective non-peptide
vasopressin
V1A receptor antagonist, shifted the concentration-response curve for
vasopressin
to the right without decreasing the maximum contraction. Antagonism became competitive with a pA2 value (+/- S.D.) of 9.72 +/- 0.20 during inhibition of nitric oxide release. [Mpa1,D-Arg8]Vasopressin (desmopressin; 0.1-100 nM), or
vasopressin
(0.01-1 nM) after blockade of the
vasopressin
V1A receptor by SR 49059, induced no vasopressin V2 receptor-related renal relaxation in kidneys with vascular tone previously restored by noradrenaline or prostaglandin F2 alpha. These findings indicate that in the isolated perfused rat kidney
vasopressin
is a potent renal vasoconstrictor. The constriction depends on activation of smooth muscle
vasopressin
V1A receptors and is modulated by endothelial nitric oxide but not by prostacyclin or vasopressin V2 receptor-related vasodilation.
...
PMID:Vascular effects of [Arg8]vasopressin in the isolated perfused rat kidney. 895 54
The
vasopressin
receptor subtype that causes nitric oxide (NO) release remains controversial. To elucidate this receptor-ligand interaction, we examined the effects of
vasopressin
receptor antagonists on
vasopressin
-induced release of NO from isolated perfused rat kidneys by using a sensitive chemiluminescence assay. Vasopressin increased renal perfusion pressure and NO signals in the perfusate in a dose-dependent manner. N omega-Monomethyl-L-arginine abolished this increase in NO release; however, a similar increase in renal perfusion pressure induced by prostaglandin F2 alpha was not associated with the increase in NO release. OPC-21268, a V1 receptor antagonist, significantly reduced the
vasopressin
-evoked renal vasoconstriction and NO release, whereas OPC-31260, a V2 receptor antagonist, had no effects. Moreover, desmopressin, a selective V2 receptor agonist, did not increase the NO signal. NO release by
vasopressin
was markedly attenuated in deoxycorticosterone acetate (DOCA)-salt hypertensive rat kidneys compared with control kidneys (10(-10) mol/L
vasopressin
: +0.8 +/- 0.3 versus +6.9 +/- 1.4 fmol/min per gram kidney, DOCA versus control; P < .001). Histochemical analysis for renal
NO synthase
revealed a substantial attenuation of the staining of endothelial
NO synthase
in DOCA-salt rats. These results directly demonstrate that
vasopressin
stimulates NO release via the endothelial V1 receptor in the rat kidney.
...
PMID:Receptor subtype for vasopressin-induced release of nitric oxide from rat kidney. 903 81
The hypothalamo-neurohypophysial system contains high levels of neuronal nitric oxide synthase and this increases further during times of neurohormone demand, such as that following osmotic stimulation. Using double in situ hybridization, we demonstrate here an increase in the expression of
nitric oxide synthase
messenger RNA by oxytocin neurons, but not
vasopressin
neurons, of the supraoptic nucleus at the time of lactation, when oxytocin is in demand due to another neuroendocrine stimulus, the milk-ejection reflex. In addition, using immunocytochemical retrograde tracing, we show that neurons of the subfornical organ, median preoptic nucleus and organum vasculosum of the lamina terminalis, which project to the supraoptic nucleus, contain
nitric oxide synthase
. These three structures of the lamina terminalis, together with the hypothalamo-neurohypophysial system, make up the forebrain osmoresponsive circuit that controls osmotically-stimulated release of oxytocin in the rat. The expression of
nitric oxide synthase
messenger RNA in the lamina terminalis was also shown to increase during lactation. The increases in
nitric oxide synthase
messenger RNA were not apparent during pregnancy. These results provide evidence for an integrated
nitric oxide synthase
-containing neural network involved in the regulation of the hypothalamo-neurohypophysial axis. The expression of
nitric oxide synthase
messenger RNA increases in this circuit during lactation and correlates with a reduction in the sensitivity of the circuit to osmotic stimuli also present in lactation but not pregnancy. As nitric oxide is believed to attenuate neurohormone release, it seems that the increased
nitric oxide synthase
messenger RNA expression detected here during lactation at a time of high oxytocin demand may be involved in reducing the sensitivity of the whole forebrain circuit to osmotic stimuli.
...
PMID:Up-regulation of nitric oxide synthase messenger RNA in an integrated forebrain circuit involved in oxytocin secretion. 904 72
Intense electrical activity throughout the brain which results from generalized epileptic or kindled seizures is thought to cause persistent and widespread neuronal plastic changes. We have previously reported that stage 5 kindled seizures cause an increase in
vasopressin
messenger RNA content and
nitric oxide synthase
activity in neuroendocrine cells of the supraoptic nucleus which lasts for at least four months after the last seizure. To evaluate whether changes in the expression of N-methyl-D-aspartate receptor subunits might contribute to these effects, the expression of NR1, NR2A, NR2B. NR2C and NR2D subunit messenger RNAs was examined by in situ hybridization in neuroendocrine cells of the supraoptic nucleus one month after amygdala kindling to stage 5 seizures. No change in NR1 subunit messenger RNA expression was seen. In contrast, NR2B subunit messenger RNA was significantly increased. by about 63%, and NR2D subunit messenger RNA was significantly decreased, by about 22%. indicating a shift in NR2 subunit messenger RNA expression. NR2B subunit messenger RNA was also significantly increased in adjacent limbic structures. The long-lasting shift towards increased NR2B and decreased NR2D messenger RNA expression after kindling suggests that N-methyl-D-aspartate receptor NR2 composition may be an important factor in the maintenance of pathological plasticity following generalized seizures. If these changes in messenger RNA are translated into increased NR2B and decreased NR2D subunits in the N-methyl-D-aspartate receptors in vivo, both a decrease in sensitivity due to a strong magnesium block and an increase in channel ion gating might be predicted.
...
PMID:Amygdala kindling alters N-methyl-D-aspartate receptor subunit messenger RNA expression in the rat supraoptic nucleus. 913 Jul 80
Recent work has demonstrated that the brain has the capacity to synthesize impressive amounts of the gases nitric oxide (NO) and carbon monoxide (CO). There is growing evidence that these gaseous molecules function as novel neural messengers in the brain. This article reviews the pertinent literature concerning the putative role of NO and CO as critical neurotransmitters and biological mediators of the neuroendocrine axis. Abundant evidence is presented which suggests that NO has an important role in the control of reproduction due to its ability to control GnRH secretion from the hypothalamus. NO potently stimulates GnRH secretion and also appears to mediate the action of one of the major transmitters controlling GnRH secretion, glutamate. Evidence is presented which suggests that NO stimulates GnRH release due to its ability to modulate the heme-containing enzyme, guanylate cyclase, which leads to enhanced production of the second messenger molecule, cGMP. A physiological role for NO in the preovulatory LH surge was also evidenced by findings that inhibitors and antisense oligonucleotides to
nitric oxide synthase
(
NOS
) attenuate the steroid-induced and preovulatory LH surge. CO may also play a role in stimulating GnRH secretion as heme molecules stimulate GnRH release in vitro, an effect which requires heme oxygenase activity and is blocked by the gaseous scavenger molecule, hemoglobin. Evidence is also reviewed which suggests that NO acts to restrain the hypothalamic-pituitary-adrenal (HPA) axis, as it inhibits HPA stimulation by various stimulants such as interleukin-1 beta,
vasopressin
, and inflammation. This effect fits a proinflammatory role of NO as it leads to suppression of the release of the anti-inflammatory corticosteroids from the adrenal. Although not as intensely studied as NO, CO has been shown to suppress stimulated CRH release and may also function to restrain the HPA axis. Evidence implicating NO in the control of prolactin and growth hormone secretion is also reviewed and discussed, as is the possible role of NO acting directly at the anterior pituitary. Taken as a whole, the current data suggest that the diffusible gases, NO and CO, act as novel transmitters in the neuroendocrine axis and mediate a variety of important neuroendocrine functions.
...
PMID:Gaseous transmitters and neuroendocrine regulation. 920
The presence of abundant
nitric oxide synthase
(
NOS
) in magnocellular neurons of the rat hypothalamus suggests that nitric oxide (NO) may be involved in controlling the release of oxytocin and
vasopressin
. To test this possibility, we examined the effect of NO-related drugs on extracellular discharges of 124 supraoptic nucleus (SON) neurons from slices of rat hypothalamus in vitro. Twenty-three (43%) of 53 neurons were inhibited by sodium nitroprusside (SNP), a spontaneous releaser of NO, at 1-3 mM. This inhibition was prevented by preincubation of the slices with 1 microM hemoglobin, an inactivator of NO (n = 14), whereas hemoglobin alone enhanced neuronal activity in seven (35%) of 20 neurons. L-Arginine (1 mM), a precursor of NO, inhibited neuronal activity in five (36%) of 14 neurons, while D-arginine (1 mM), the inactive counterpart of L-arginine, was ineffective (n = 12). N-omega-nitro-L-arginine methyl ester (L-NAME, 10 microM), an inhibitor of
NOS
, also enhanced neuronal activity in five (29%) of 17 neurons, while N-omega-nitro-D-arginine methyl ester (DNAME, 10 microM), the inactive enantiomer of L-NAME, was without effect (n = 11). Together, our data show that NO exerts predominantly an inhibitory effect on SON neurons and may serve as a negative feedback loop in controlling release of oxytocin and
vasopressin
.
...
PMID:Nitric oxide inhibits neuronal activity in the supraoptic nucleus of the rat hypothalamic slices. 922 24
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