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Query: UNIPROT:P01185 (
vasopressin
)
23,126
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
1. The effect of neuropeptide Y (NPY) on cardiovascular function at three levels of the noradrenergic axis where the peptide is known to co-exist with noradrenaline (NA) and or adrenaline (A) was studied in normotensive Sprague-Dawley (SD), Wistar-Kyoto (WKY) or spontaneously hypertensive rats (SHR). 2. In the perfused mesenteric arterial bed, NPY and the structurally similar peptide intestinal polypeptide (
PYY
) decreased the periarterial nerve stimulation induced release of NA and potentiated the increase in perfusion pressure to nerve stimulation or exogenously applied agonists (e.g. angiotensin,
vasopressin
, phenylephrine). In contrast to NPY and
PYY
, C-terminal NPY fragments inhibited NA release and produced a parallel decrease in perfusion pressure thus supporting the concept of Y1 (post) and Y2 (pre) NPY receptors. 3. In the mesenteric artery of SHR the prejunctional inhibitory effect of NPY was attenuated while the postjunctional response was enhanced. 4. Following intrathecal (Int) injection of NPY, there was a decrease in blood pressure, total peripheral resistance (predominantly by a decrease in mesenteric vascular resistance) and renal nerve activity. The depressor effect of Int NPY was attenuated in the SHR. 5. Unilateral injections of NPY into the posterior hypothalamic nucleus increased blood pressure, hindquarter and renal vascular resistance and renal nerve activity. The pressor effect was enhanced in the SHR. 6. Periarterial nerve stimulation of the perfused mesenteric artery produced a frequency dependent vasodilation in beds pretreated with guanethidine and precontracted with methoxamine.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Neuropeptides in hypertension: role of neuropeptide Y and calcitonin gene related peptide. 226 10
The effects of neuropeptide Y (NPY) on LHRH release from an immortalized cell line were investigated using a flow-through cell culture superfusion system. Immortalized hypothalamic GT1-7 cells were cultured for 72 h and superfused for a total of 180 min. In initial experiments, discrete 5-min pulses of NPY (10(-12)-10(-5) M) were administered to the cells. A clear dose-dependent stimulatory effect on NPY on LHRH release from the cells was observed with a calculated 50% effectiveness concentration of 33 nM. The stimulatory effects of brief NPY exposure were rapid and robust, e.g. reaching and maintaining levels of 173% over baseline for 20 min at the 10(-7) dose. The lowest dose of NPY that showed a significant effect was 10(-10) M; maximal responses were observed at 10(-6) M and reached a plateau thereafter. Control pulses of Dulbecco's modified Eagle's medium (DMEM) and 10(-6) M substance P or arg-
vasopressin
were also presented to the cells to serve as controls for our pulse protocol, and these challenges produced no significant LHRH responses. The NPY receptor antagonists, PYX1 and PYX2, at 10(-8) M, completely blocked the observed NPY responses in these cells. To assess the NPY receptor subtypes that mediate the NPY effects pharmacologically, GT1-7 cells were challenged with a Y1 receptor agonist, (Leu31Pro34)NPY, a Y2 receptor agonist, NPY(13-36), or
peptide YY
, at doses 10(-12)-10(-5) M. All four peptides stimulated LHRH release from GT1-7 cells with a rank-ordered potency of NPY =
peptide YY
> Y1 agonist = Y2 agonist. To examine possible signal transduction mechanism(s) involved in mediating this effect, pertussis toxin, RpcAMPs (cyclic adenosine-3'5'-monophosphothioate Rp diastereomer), Ca(2+)-free DMEM and TMB-8 (3, 4, 5-trimethoxybenzoic acid 8-(diethylamino) octylester) were used to treat the cells before and during superfusion with NPY. Treatment with pertussis toxin, RpcAMPs, and Ca(2+)-free DMEM did not significantly alter NPY-stimulated LHRH release responses to 10(-7) M NPY. However, the addition of 100 microM and 250 microM TMB-8 to Ca(2+)-free DMEM almost completely blocked this NPY effect, as did 10 microM ryanodine. Finally, the locus of action for this NPY effect was examined using tetrodotoxin to reduce action potential propagation in the GT1-7 cells. Tetrodotoxin treatment blocked the LHRH response to NPY by more than 50%.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Neuropeptide Y stimulates luteinizing hormone-releasing hormone release from superfused hypothalamic GT1-7 cells. 792 25
This paper reviews the recent progress in the understanding of the neurobiology of the eating disorders. The analysis of the biochemical abnormalities present in the patients with bulimia nervosa indicates the decrease of central serotonin and noradrenalin activity, elevation of the levels of cerebrospinal fluid
peptide YY
, alterations of the endogenous opioids and also reduction of peripheral cholecystokinin levels. As these studies were performed on patients who were actively binging and purging it is conceivable that the above abnormalities can results from a pathological feeding pattern. It is also suggested that the reduction of central serotoninergic activity is the stable, trait-related dysregulation of neurotransmitter system activity. In patients with anorexia nervosa the endocrine disturbances of the hypothalamic-pituitary-ovarian and hypothalamic-pituitary-adrenal axes were thoroughly studied. Underweight anorectic patients have been found to have elevations of cerebrospinal fluid level of neuropeptide Y, corticotropin releasing hormone and
vasopressin
as well as reductions of beta-endorphin and oxytocin level. However, most of the neuropeptide alterations normalize following weight recovery. The only exception is a persistent increase of central serotonin activity postulated to be responsible for the obsessive-compulsive personality traits and disturbed eating behaviors found in these patients.
...
PMID:[Selected issues of biological aspects of eating disorders]. 799 11
Neuropeptide Y (NPY) is a co-transmitter of the sympathetic nervous system including the renal nerves. The kidney expresses NPY receptors, which can also be activated by
peptide YY
(
PYY
), a circulating hormone released from gastrointestinal cells. Five subtypes of NPY receptors have been cloned, among which Y1, Y2 and Y5 appear to be involved in the regulation of renal function. NPY produces potent renal vasoconstriction in vitro in isolated interlobar arteries and in the isolated perfused kidney and in vivo upon intrarenal or systemic administration via a Y1 receptor. Nevertheless glomerular filtration rate is altered only little if at all by NPY, indicating a greater effect on the vas efferens than the vas afferens. NPY can inhibit renin release via Y1-like receptors. NPY can stimulate Na+/K+ adenosine triphosphatase (Na+/K+-ATPase) in proximal tubules via Y2 receptors and can antagonize the effects of
vasopressin
on isolated collecting ducts. It can also act prejunctionally to inhibit noradrenaline release via Y2 receptors. Despite the profound reductions of renal blood flow, systemic NPY infusion can cause diuresis and natriuresis; this is largely independent of pressure natriuresis mechanisms and is possibly mediated by an extrarenal Y5 receptor. Studies with the converting enzyme inhibitor ramiprilat and the bradykinin receptor antagonist icatibant indicate that bradykinin mediates, at least partly, diuretic NPY effects. NPY antagonists enhance basal renal blood flow but do not alter basal diuresis or natriuresis indicating that renovascular, but not tubular, NPY receptors may be tonically activated by endogenous NPY.
...
PMID:Renal effects of neuropeptide Y. 944 90
Neuropeptide Y and
peptide YY
are important central and peripheral modulators of cardiovascular and neuroendocrine functions, that act through multiple receptor subtypes, Y1 through Y5. A neuropeptide Y-binding site of the Y2 type was characterized by ligand-binding studies in isolated nerve terminals from the rat neurohypophysis. Functionally, neuropeptide Y and
peptide YY
dose-dependently triggered arginine 8-
vasopressin
and oxytocin release from perfused isolated terminals, and potentiated the arginine-8-
vasopressin
release induced by depolarization. Osmotic stimulation by salt loading of rats for two and seven days caused a more than three-fold increase in the neuropeptide Y content of the nerve endings. However, the Y2 receptor expression and arginine-8-
vasopressin
content declined, showing that the neuropeptide Y system is dynamic and suggesting that it plays a physiological role in salt and water homeostasis. Two sets of observations suggest the arginine-8-
vasopressin
release by neuropeptide Y may not be explained by neuropeptide Y effects on intracellular Ca2+. First, absence of Ca2+ from the perfusion medium did not affect the arginine-8-
vasopressin
release, and secondly neuropeptide Y did not change intraterminal Ca2+ concentrations. Pretreatment with pertussis toxin blocked arginine-8-
vasopressin
secretion by neuropeptide Y, suggesting activation of Gi or Go heterotrimeric G-proteins are required for secretion. It is concluded, that the nerve endings of the neurohypophysis contain a complete neuropeptide Y system with ligand and receptors. Neuropeptide Y may act in an autocrine fashion via activation of Y2 neuropeptide Y receptors to stimulate the release of
vasopressin
and oxytocin via a Gi/Go dependent secretory mechanism.
...
PMID:Neuropeptide Y2 receptors on nerve endings from the rat neurohypophysis regulate vasopressin and oxytocin release. 948 7
mIMCD-k2 cells are derived from the inner medullary collecting duct of a mouse and exhibit electrogenic sodium absorption and cAMP- and
vasopressin
(AVP)-stimulated electrogenic chloride secretion [N. L. Kizer, B. Lewis, and B. A. Stanton. Am. J. Physiol. 268 (Renal Fluid Electrolyte Physiol. 37): F347-F355, 1995; and N. L. Kizer, D. Vandorpe, B. Lewis, B. Bunting, J. Russell, and B. A. Stanton. Am. J. Physiol. 268 (Renal Fluid Electrolyte Physiol. 37): F854-F861, 1995]. The purpose of the present study was to determine how
peptide YY
(
PYY
) affects electrogenic Na+ and Cl- current in mIMCD-k2 cells. Short-circuit currents (Isc) were measured across monolayers of mIMCD-k2 cells mounted in Ussing-type chambers.
PYY
did not alter baseline Isc, nor did it alter Isc in chloride-free conditions, indicating no effect on electrogenic sodium transport. Baseline chloride current in these cells is low; therefore, chloride short-circuit current (IClsc) was stimulated with AVP (10 nM) added to the basolateral surface and 10 microM amiloride added to the apical surface. Although apical applications of
PYY
had no effect, basolateral application of
PYY
caused attenuation of IClsc, with the maximal inhibitory dose (100 nM) causing 52 +/- 1.3% inhibition (IC50 = 0.11 nM). Inhibition by
PYY
of IClsc is mediated through the Y2 receptor subtype, as
PYY
-(3-36) was the only
PYY
analog tested that caused inhibition and was equipotent to
PYY
. Inhibition by
PYY
of IClsc was abolished following incubation with pertussis toxin. We also show that
PYY
inhibits AVP-stimulated cAMP accumulation, with a maximal inhibitory dose (100 nM) causing a 38% +/- 6% inhibition (IC50 = 0.16 nM), comparable to inhibition by
PYY
of IClsc. We conclude that
PYY
acts through either Gi or Go to inhibit adenylate cyclase activity, leading to a decrease in AVP-stimulated chloride current.
...
PMID:Peptide YY inhibits vasopressin-stimulated chloride secretion in inner medullary collecting duct cells. 972 20
Bulimia nervosa is an eating disorder characterised by recurrent episodes of binge eating and associated efforts to purge the ingested calories through self-induced vomiting, laxative or diuretic abuse, fasting or intensive exercise. The aetiopathogenesis and pathophysiology of the disorder are currently unclear. Biological bases have been proposed repeatedly, based on several lines of evidence: hunger, satiety and food choice are regulated by neurotransmitters and neuropeptides, and impairment of eating habits may be related to alterations in the secretion of these chemicals; genetic studies suggest that these neurotransmitter systems are dysfunctional in individuals with bulimia nervosa; and the frequent comorbidity of bulimia nervosa with major depressive and obsessive-compulsive disorders, conditions in which multiple alterations of brain biochemical functions have been demonstrated. Data in the literature suggest that levels of noradrenaline (norepinephrine) and serotonin (5-hydroxytryptamine; 5-HT) are lower in individuals with bulimia nervosa than in healthy controls. Levels of dopamine are similar to, or lower than, those in controls. After remission of the disorder, noradrenergic function returns to that seen in controls, whereas dopaminergic and serotonergic function rebound to levels higher than in controls. Among the neuropeptides, alterations in the levels of neuropeptide Y,
peptide YY
, beta-endorphin, corticotrophin-releasing hormone, somatostatin, cholecystokinin and
vasopressin
have been found in the symptomatic phase of bulimia nervosa, with a return to levels seen in controls after remission. Pharmacological treatment of bulimia nervosa that is directed at correction of the neurochemical alterations observed is difficult because of the complexity of the impairments. However, such treatment is necessary and should be continued long after symptomatic remission to ensure reinstitution of cerebral biochemical homeostasis.
...
PMID:Aetiopathogenesis and pathophysiology of bulimia nervosa: biological bases and implications for treatment. 1146 Aug 90
Neuropeptides play an important role in the regulation of feeding behavior and obesity. The mechanisms for controlling food intake involve a complicated interplay between peripheral systems (including gustatory stimulation, gastrointestinal peptide secretion, and vagal afferent nerve responses) and central nervous system (CNS) neuropeptides and/or monoamines. These neuronal systems include neuropeptides (CRH, opioids, neuropeptide-Y (NPY) and
peptide YY
(
PYY
),
vasopressin
and oxytocin, CCK, and leptin) and monamines (serotonin, dopamine, norepinephrine). In addition to regulating eating behavior, a number of CNS neuropeptides participate in the regulation of neuroendocrine pathways. Thus, clinical studies have evaluated the possibility that CNS neuropeptide alterations may contribute to dysregulated secretion of the gonadal hormones, cortisol, thyroid hormones and growth hormone in the eating disorders. Most of the neuroendocrine and neuropeptide alterations apparent during symptomatic episodes of AN and BN tend to normalize after recovery. This observation suggests that most of the disturbances are consequences rather than causes of malnutrition, weight loss and/or altered meal patterns. Still, an understanding of these neuropeptide disturbances may shed light on why many people with AN or BN cannot easily "reverse" their illness and even after weight gain and normalized eating patterns, many individuals who have recovered from AN or BN have physiological, behavioral and psychological symptoms that persist for extended periods of time.
...
PMID:A review of neuropeptide and neuroendocrine dysregulation in anorexia and bulimia nervosa. 1276 12
Anorexia and Bulimia Nervosa are disorders of unknown etiology that invariably begin during adolescence and near in time to puberty in young women. These disorders are associated with aberrant eating behaviors, body image distortions, impulse and mood disturbances, as well as characteristic temperament and personality traits. It is well known that malnutrition produces changes in neuroendocrine function. More recently, disturbances in neuronal systems have been found to play a role in the modulation of feeding, mood, and impulse control. These neuronal systems include neuropeptides (CRH, opioids, neuropeptide-Y (NPY) and
peptide YY
(
PYY
),
vasopressin
and oxytocin, CCK, and leptin) and monoamines (serotonin, dopamine, norepinephrine). Disturbances of most of these neuronal systems have been found when people are ill with an eating disorder, but it was not certain whether they were a cause or consequence of symptoms. In order to address these questions, a growing number of studies have investigated whether neuromodulatory disturbances persist after recovery. Studies from several centers tend to show altered serotonin activity persists after prolonged normalization of weight, nutrition, and menstrual function, as do anxiety, obsessionality, and perfectionism. While there are fewer data, there may be persistent alterations of dopamine or some neuropeptides in some subjects in a recovered state. The inaccessibility of the central nervous system has made it difficult to understand brain and behavior. In the past decade, new tools, such as brain imaging, have offered the possibility of better characterization of complex neuronal function and behavior. Such studies have tended to consistently find that alterations of brain regions, such as the temporal lobe, occur in people who are ill with anorexia nervosa and appear to persist after some degree of weight gain and recovery. New imaging technology, that marries Positron Emission Tomography (PET) imaging with selective neurotransmitter radioligands, confirms that altered serotonin neuronal pathway activity persists after recovery from an eating disorder and supports the possibility that these psychobiological alterations might contribute to traits, such as increased anxiety or extremes of impulse control, that, in turn, may contribute to a vulnerability to the development of an eating disorder. In summary, studies of pathophysiology are starting to nominate new candidates for treatment leading to the possibility of finding effective treatments for this often chronic or fatal disorder.
...
PMID:Neurotransmitter and imaging studies in anorexia nervosa: new targets for treatment. 1276 13
1 Microinjection of
peptide YY
(
PYY
) (0.23-2.3 nmol) into the posterior hypothalamic nucleus (PHN) of conscious rats evokes a dose-dependent pressor response and a bradycardia. 2 The increase in mean arterial pressure evoked by 2.3 nmol of
PYY
was not blocked by intravenous pretreatment with: (i) the nicotinic ganglionic receptor antagonist pentolinium (PENT, 10 mg kg(-1)) alone, or in combination with the muscarinic receptor antagonist methylatropine (MeATR, 1 mg kg(-1)); (ii) the alpha(1)-adrenoceptor antagonist prazosin (PRAZ, 0.2 mg kg(-1)); (iii) the V(1)-
vasopressin
receptor antagonist [d(CH(2))(5)Tyr(Me)]AVP (AVPX, 20 microg kg(-1)); (iv) the combination of AVPX, PENT and MeATR; (v) the combination of PRAZ, AVPX, PENT, MeATR, and the alpha(2)-adrenoceptor antagonist yohimbine (0.3 mg kg(-1)); or (vi) the angiotensin II type 1 receptor antagonist ZD 7155 (1 mg kg(-1)). 3 Adrenal demedullation inhibited the
PYY
-evoked responses of drug-naive rats, and rats pretreated with the combination of PENT, MeATR and AVPX. 4 Transection of the splanchnic nerve innervating the adrenal medullae attenuated the bradycardia, as did ZD 7155, but not the
PYY
-evoked pressor response. 5 Systemic pretreatment of rats with the neuropeptide Y(1) receptor antagonist BIBP 3226 (1 mg kg(-1)) blocked the
PYY
-evoked cardiovascular changes, but not those evoked by microinjection of carbachol (5.5 nmol) into the PHN. 6 These results suggest that the cardiovascular changes evoked from the PHN by
PYY
requires the presence of the adrenal medullae, which are stimulated by: (i) a hormone to release an NPY-like substance that evokes the pressor response, and (ii) the splanchnic nerve to evoke the release of a substance that results in the bradycardia.
...
PMID:Peptide YY administration into the posterior hypothalamic nucleus of the rat evokes cardiovascular changes by non-adrenergic, non-cholinergic mechanisms. 1575 5
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