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)

Oxytocin and vasopressin release from magnocellular neurons of the supraoptic nucleus is under the control of glutamate-dependent excitation. The supraoptic nucleus also receives a generalized dopaminergic input from hypothalamic sources. To determine if dopamine can influence this excitatory drive onto the magnocellular neurons, we used whole-cell patch clamp to record the effect of dopamine on evoked and miniature excitatory postsynaptic currents in rat hypothalamic slices. Dopamine exposure (30 microM to 1 mM) induced a large and reversible reduction in the amplitude of evoked excitatory postsynaptic current in nearly all magnocellular cells tested. D4 receptors appeared to mediate dopamine's activity, based on inhibition of the response with 50 microM clozapine, but not by SCH 23390 or sulpiride, and mimicry of dopamine's action with the D4 specific agonist, PD 168077. Analysis of paired-pulse experiments and miniature postsynaptic currents indicated that dopamine's action involved a presynaptic mechanism, since the frequency of miniature postsynaptic currents was reduced with dopamine exposure without any change in current kinetics or amplitude, while the paired-pulse ratio increased. We therefore have demonstrated for the first time a role for dopamine D4 receptors in the supraoptic nucleus in the presynaptic inhibition of glutamatergic neurotransmission onto magnocellular neurons.
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PMID:Dopamine D4 receptor activation inhibits presynaptically glutamatergic neurotransmission in the rat supraoptic nucleus. 1153 65

Dopamine D4 receptors mediate inhibition of vasopressin-dependent sodium reabsorption by dopamine in collecting tubules. At present, the distribution of D4 receptors in other renal districts remains an open issue. The renal distribution of D4 receptor was assessed in normally innervated and denervated male Sprague-Dawley rats by quantitative immunohistochemistry using an anti-dopamine D4 receptor rabbit polyclonal antibody. D4 receptor protein immunoreactivity was observed perivascularly in the adventitia and the adventitia-media border. The density of perivascular dopamine D4 receptor was higher in afferent and efferent arterioles than in other segments of the renal vascular tree. Renal denervation abolished perivascular dopamine D4 receptor protein immunoreactivity. In renal tubules, the epithelium of collecting tubules showed the highest dopamine D4 receptor protein immunoreactivity, followed by the epithelium of proximal and distal tubules. No dopamine D4 receptor protein immunoreactivity was observed in the epithelium of the loop of Henle. Denervation did not change dopamine D4 receptor protein immunoreactivity in renal tubules. These results indicate that rat kidney expresses dopamine D4 receptors located both prejunctionally and nonprejunctionally in collecting, proximal, and distal tubules. This suggests that the dopamine D4 receptor may be involved in the control of neurotransmitter release and in renal hemodynamic and tubule function.
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PMID:Dopamine D4 receptor expression in rat kidney: evidence for pre- and postjunctional localization. 1213 12

The hepatorenal syndrome (HRS) is a unique form of acute renal failure with entirely normal renal histology in advanced liver disease. Its diagnosis is made by exclusion of all causes of renal failure and by all the five major criteria as set by the International Ascites Club. The presence of hepatomegaly, poor nutritional status, and oesophageal varices at endoscopy are associated with a high risk of HRS. The liver tests, the Child-Pugh score, are of no value in prediction of its occurrence. Contraction of the effective blood volume, which may lead to renal hypoperfusion with preferential renal cortical ischaemia, is proposed pathogenesis of the condition. Because understanding of the pathogenesis of HRS is incomplete, therapy is supportive only. Optimal fluid management is vital as there is almost invariably a reduction in effective arterial blood volume. Dopamine, frusemide and haemofiltration may be helpful in management of fluid overload but do not affect renal function. TIPS has been used successfully in small series of patients. The vasopressin analog also has been used with early excellent response. The treatment of HRS has been discouraging and the only proven cure for HRS is liver transplantation at this point of time.
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PMID:Hepatorenal syndrome: pathophysiology and treatment. 1224 Aug 52

The effect of galanin (GAL) on vasopressin (VP) secretion was studied in 13-14-day cultures of isolated rat neurohypophyseal (NH) tissue. The VP content of the supernatant was determined by radioimmunoassay (RIA) after a 1- or 2-h incubation. A significantly decreased content of VP was detected following the administration of 10(-6)-10(-9) M doses of GAL. Dopamine (DA) and the DA-active drugs apomorphine (APM) and Pro-Lys-Gly (PLG) (10(-6) M in each medium) increased the VP level of NH tissue cultures. This VP concentration elevation could be blocked by the administration of GAL together with DA, APM or PLG. The DA-blocking effect of GAL was prevented by previous treatment with the GAL receptor antagonist galantid (M15). The results indicate that VP release is directly influenced by the GAL-ergic system. The GAL-ergic control of VP secretion from NH tissue in rats can occur independently of the hypothalamus, at the level of the posterior pituitary.
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PMID:Inhibitory effect of galanin on dopamine-induced enhanced vasopressin secretion in rat neurohypophyseal tissue cultures. 1246 5

Dopamine is an important transmitter in the CNS and PNS, critically regulating numerous neuropsychiatric and physiological functions. These actions of dopamine are mediated by five distinct receptor subtypes. Of these receptors, probably the least understood in terms of physiological functions is the D5 receptor subtype. To better understand the role of the D5 dopamine receptor (DAR) in normal physiology and behavior, we have now used gene-targeting technology to create mice that lack this receptor subtype. We find that the D5 receptor-deficient mice are viable and fertile and appear to develop normally. No compensatory alterations in other dopamine receptor subtypes were observed. We find, however, that the mutant mice develop hypertension and exhibit significantly elevated blood pressure (BP) by 3 months of age. This hypertension appears to be caused by increased sympathetic tone, primarily attributable to a CNS defect. Our data further suggest that this defect involves an oxytocin-dependent sensitization of V1 vasopressin and non-NMDA glutamatergic receptor-mediated pathways, potentially within the medulla, leading to increased sympathetic outflow. These results indicate that D5 dopamine receptors modulate neuronal pathways regulating blood pressure responses and may provide new insights into mechanisms for some forms of essential hypertension in humans, a disease that afflicts up to 25% of the aged adult population in industrialized societies.
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PMID:Mice lacking D5 dopamine receptors have increased sympathetic tone and are hypertensive. 1248 73

Hepatorenal syndrome is a life-threatening complication occurring commonly in cirrhosis liver and rarely in acute liver failure. It can be precipitated by shock, infection, surgery, large volume paracentesis or nephrotoxic drugs. Type I hepatorenal syndrome which usually develops over acute liver failure is rapidly progressive and has poor outcome. Type II hepatorenal syndrome is usually associated with refractory ascites and is slowly progressive with relatively good prognosis. Peripheral vasodilation with intrarenal vasoconstriction is the main pathophysiologic change. Diagnostic criteria, ascertained by international ascites club, is helpful to reach at a proper diagnosis. Management includes pharmacologic therapy to induce splanchnic vasoconstriction which improve renal circulation. Dopamine, vasopressin analogs (ornipressin and terlipressin), midodrine, noradrenaline have been used mainly as a bridge to the liver transplant or in anticipation of improvement in hepatic function. The molecular adsorbent recycling system (MARS) have been recently used in patients with hepatorenal syndrome. Transjugular intrahepatic portosystemic shunt is also another modality which has been used as a bridge to liver transplant in such patients.
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PMID:Hepatorenal syndrome. 1269 50

The mechanism by which dopamine induces or facilitates neurohypophysial hormone release is not completely understood. Because oxytocin- and vasopressin-secreting supraoptic neurons are under the control of a prominent GABAergic inhibition, we investigated the possibility that dopamine exerts its action by modulating GABA-mediated transmission. Whole cell voltage-clamp recordings of supraoptic neurons were carried out in acute hypothalamic slices to determine the action of dopamine on inhibitory postsynaptic currents. Application of dopamine caused a consistent and reversible reduction in the frequency, but not the amplitude, of miniature synaptic events, indicating that dopamine was acting presynaptically to reduce GABAergic transmission. The subtype of dopamine receptor involved in this response was characterized pharmacologically. Dopamine inhibitory action was greatly reduced by two highly selective D4 receptor antagonists L745,870 and L750,667 and to a lower extent by the antipsychotic drug clozapine but was unaffected by SCH 23390 and sulpiride, D1/D5 and D2/D3 receptor antagonists, respectively. In agreement with these results, the action of dopamine was mimicked by the potent D4 receptor agonist PD168077 but not by SKF81297 and bromocriptine, D1/D5 and D2/D3 receptor agonists, respectively. Dopamine and PD168077 also reduced the amplitude of evoked inhibitory postsynaptic currents, an effect that was accompanied by an increase in paired-pulse facilitation. These data clearly indicate that D4 receptors are located on GABA terminals in the supraoptic nucleus and that their activation reduces GABA release in the supraoptic nucleus. Therefore dopaminergic facilitation of neurohypophysial hormone release appears to result, at least in part, from disinhibition of magnocellular neurons caused by the depression of GABAergic transmission.
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PMID:Dopamine D4 receptor-mediated presynaptic inhibition of GABAergic transmission in the rat supraoptic nucleus. 1271 14

Dopamine is a pressor agent in the spinal cat, but causes a fall of blood pressure in the guinea-pig and rabbit under urethane anaesthesia. When guinea-pigs and rabbits are injected with reserpine, which depletes the vessel walls of noradrenaline, dopamine then becomes pressor. If an intravenous infusion of noradrenaline is given the depressor action returns. An intravenous infusion of vasopressin does not have this effect.A strip of rabbit aorta is caused to contract by noradrenaline and by dopamine, but if dopamine is added at the height of a noradrenaline contraction it causes relaxation.Adrenaline causes a fall of blood pressure in the cat under ether with vagi cut. However, in a reserpine-treated cat its action is pressor. The depressor action is restored during an infusion of noradrenaline. Noradrenaline has thus been shown to cause a vasomotor reversal of dopamine and of adrenaline.
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PMID:The depressor action of dopamine and adrenaline. 1361 54

The regulation of oxytocin (OT) release by galanin (GAL) at the neurohypophyseal (NH) nerve terminal is not adequately understood. The effect of GAL on the secretion of OT was studied in 13- to 14-day cultures of isolated rat NH tissue. By this time, the hormone content of the medium had become constant. The OT content of the supernatant medium was determined by RIA after a 1- or 2-h incubation. A significantly decreased content of OT was found following incubation with 10(-6)-10(-8) M doses of GAL. Dopamine (DA) and the DA-active drugs apomorphine (APM) and Pro-Lys-Gly (PLG) (10(-6) M in each medium) increased the OT synthesis of NH tissue cultures. This elevation of OT secretion could be blocked by the administration of GAL together with DA, APM or PLG. The DA-blocking effect of GAL was prevented by previous treatment with the GAL receptor antagonist galantid (M15). The results indicate that OT release from the NH is directly influenced by the GAL-ergic system. The GAL-ergic control of OT secretion from NH tissue in rats can occur at the level of the posterior pituitary.
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PMID:Inhibitory effect of galanin on dopamine induced increased oxytocin secretion in rat neurohypophyseal tissue cultures. 1459 13

Dopamine is an important regulator of blood pressure. Its actions on renal hemodynamics, epithelial transport and humoral agents such as aldosterone, catecholamines, endothelin, prolactin, pro-opiomelanocortin, renin and vasopressin place it in central homeostatic position for regulation of extracellular fluid volume and blood pressure. Dopamine also modulates fluid and sodium intake via actions in the central nervous system and gastrointestinal tract, and by regulation of cardiovascular centers that control the functions of the heart, arteries and veins. Abnormalities in dopamine production and receptor function accompany a high percentage of human essential hypertension and several forms of rodent genetic hypertension. Some dopamine receptor genes and their regulators are in loci linked to hypertension in humans and in rodents. Furthermore, single nucleotide polymorphisms (SNPs) of genes that regulate dopamine receptors, alone or via the interaction with SNPs of genes that regulate the renin-angiotensin system, are associated with human essential hypertension. Each of the five dopamine receptor subtypes (D1, D2, D3, D4 and D5) participates in the regulation of blood pressure by mechanisms specific for the subtype. Some receptors (D2 and D5) influence the central and/or peripheral nervous system; others influence epithelial transport and regulate the secretion and receptors of several humoral agents (e.g., the D1, D3 and D4 receptors interact with the renin-angiotensin system). Modifications of the usual actions of the receptor can produce blood pressure changes. In addition, abnormal functioning of these dopamine receptor subtypes impairs their antioxidant function.
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PMID:Regulation of blood pressure by dopamine receptors. 1461 Mar 23


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