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)

After intracerebroventricular (icv) injection of arginine-vasopressin (AVP; 0.1, 1, 3, 10, 30 and 100 ng) or artificial cerebrospinal fluid (aCSF), heart rate (HR), core temperature (CT), and gross activity were monitored by a wireless telemetry system in rats in the home cage for a 60-min period. In addition, the simultaneous occurrence of various behaviors was recorded by an observer. Also, two structurally related peptides, oxytocin (OXT) and desglycinamide-arginine vasopressin (DGAVP), were tested (10 and 100 ng). Both the time-effect and dose-response relationships of AVP-induced changes in HR and CT were biphasic. Lower doses of AVP produced a tachycardia, whereas injection of higher doses of AVP caused a tachycardia preceded by a significant bradycardia. The concomitant mild rise in CT seen in rats treated with 1 and 3 ng AVP or with aCSF was attenuated in rats given 10 ng AVP; 30 ng AVP resulted in an immediate significant fall in CT, which was restored to control values at 30 min after administration. An inverted U-shaped dose-response relationship was observed for gross activity, locomotion, and rearing behavior, whereas grooming behavior was most marked after the highest dose of AVP. OXT induced a grooming response and cardiac acceleration at the 100-ng dose only, whereas DGAVP produced no effect. To investigate the role of endogenous AVP in the maintenance of tonic ANS activity under resting conditions, rats were treated intracerebroventricularly (icv) with the V1 antagonist d(CH2)5-[Tyr(Me)2]AVP or polyclonal antiserum (W1E) against AVP. During the first 10 min after icv injection of 3 and 10 ng of the antagonist, an increase in HR, CT, and behavioral activation was observed, effects opposite to those produced by the higher dose of AVP. The same variables remained unchanged after administration of 100 ng of the antagonist. W1E injected icv was without effect. In summary, central effects of AVP on autonomic and behavioral activity seem to be mediated by differential neural pathways. In addition, a structure-activity relation seems to exist for the AVP-induced effects. Finally, these results suggest that AVP plays but a minor role in the maintenance of tonic activity of the ANS.
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PMID:Differential effects of centrally injected AVP on heart rate, core temperature, and behavior in rats. 843 Aug 86

The purpose of this study was to characterize the hormonal responses to a restraining system in four adult male rhesus monkeys (Macaca mulatta) in preparation for a spaceflight project. After the monkeys were accustomed to food and water (Phase I), blood-volume-regulating hormones were measured during three phases: 10 days in a metabolic cage (Phase II), 16 days sitting in a restrained position in a specially designed metabolism chair (Phase III) and 10 days in metabolic cage (Phase IV). An increase of active renin (30%) and vasopressin (25%) was observed at the end of Phase III. A decrease of atrial natriuretic peptide (ANP), urodilatin, and sodium excretion occurred during the first days of Phase III. Catecholamines were unchanged. A dramatic increase (tenfold) in urinary excretion of growth hormone occurred during all of Phase III and at the beginning of Phase IV. These findings are similar to those found in man during isolation inactivity and during confinement stress.
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PMID:Hormonal response to restraint in rhesus monkeys. 943 67

In addition to its peripheral secretion from the neurohypophysis, the neuropeptide vasopressin (VP) is released within the mammalian brain from probably all parts of the neuronal membrane. In particular the development of brain microdialysis in vivo together with blood microdialysis or blood sampling provides the advantage of being able to reliably compare the dynamic release patterns into different compartments of the organism. The central VP release within hypothalamic (e.g., supraoptic, paraventricular and suprachiasmatic nuclei) and limbic (e.g., septum, amygdala) rat brain areas is stimulated by a variety of substances and stressors, including interleukin-1 beta, social defeat and forced swimming. Furthermore, it is characterized by positive and negative feedback mechanisms and the capacity of the VP system for co-ordinated or independent release, the latter being observed, for example, during social defeat. This emotional stressor, in contrast to exposure to a novel cage, increased VP release within the supraoptic nucleus, but not into plasma. This failure to release VP peripherally could be observed also during forced swimming, despite a dramatic rise in plasma osmolality and a markedly stimulated central release. In another series of experiments we studied the effects of centrally-released VP on cognitive and emotional aspects of behavior using reverse microdialysis for antagonist administration during the behavioral tests and antisense targeting to downregulate either VP or its local V1 receptor subtype. In this way, centrally (in particular septally) released VP could be shown to be causally involved in short-term memory and anxiety-related behavior. Furthermore, VP release within the hypothalamic paraventricular nucleus is likely to provide a negative tonus on the activity of the hypothalamic-pituitary-adrenocortical axis. This neuroendocrine effect together with cognitive, emotional and immunological effects of centrally released VP is thought to be essential to ensure adequate behavior of the animal during challenging situations and to contribute to the development of efficient coping strategies.
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PMID:Release of vasopressin within the brain contributes to neuroendocrine and behavioral regulation. 1007 90

In socially organized mammals the predominating stressors are not physical events but arise from the immediate social environment of the animal. Crowding typically evokes social stress reactions with prominent psychosocial components mimicking emotional state alterations. Depending on the nature, intensity and duration of the initial stimuli, they can either reduce or increase the response of the hypothalamic-pituitary adrenal (HPA) axis. In homologous desensitization only stimulation by desensitizing hormone is attenuated, in heterologous desensitization diminished responsiveness to additional activators occurs. Social stress of crowding (21 rats in a cage for 7) for 3, 7, 14 and 21 days considerably reduced the corticosterone response to intracerebroventricular (icv) administration of carbachol, a cholinergic muscarinic receptor agonist due to a homologous desensitization and down-regulation of central muscarinic receptors by an increased secretion of acetylcholine. Crowding stress significantly reduced the HPA response to icv isoprenaline, a beta-adrenergic agonist and clonidine, an alpha2-adrenergic agonist and only moderately diminished the response to phenylephrine -- an alpha1-adrenergic agonist. The stimulatory effect of dimaprit, a nonselective histamine H2-receptor agonist on HPA axis was considerably impaired in crowded rats while the response to 2-pyridylethylamine, a H1-receptor agonist was moderately affected. Social crowding stress did not substantially alter the CRH-induced ACTH and corticosterone response while it suppressed the vasopressin-induced responses. Indomethacin did not change basal plasma ACTH and corticosterone levels, indicating that prostaglandins are not involved in basal regulation of the HPA activity. Inhibition of prostaglandins synthesis by indomethacin significantly diminished the vasopressin-induced HPA response under both basal and social stress conditions, whereas it did affect the CRH-elicited HPA stimulation under both these circumstances. Social stress inhibits the nitric oxide effect on the CRH-induced ACTH response but it does not alter the AVP-induced responses. These results indicate a specific and distinct influences of social crowding stress on the neurotransmitters- neurohormones- prostaglandins- and nitric oxide-induced HPA responses.
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PMID:Social stress adapts signaling pathways involved in stimulation of the hypothalamic-pituitary-adrenal axis. 1057 67

Tail-suspension of rats has been employed for the study of disuse atrophy of hindlimb muscles and bones. From our study, it is suggested that stress exacerbates muscle and bone atrophy; however, the determination of stress hormones has been inappropriately performed. For assessing the effect of tail suspension on stress hormone secretion, suspension was performed for 7 days in a metabolic cage. Urinary excretions of corticosterone, catecholamines and antidiuretic hormone were determined during the 7-day suspension. Urine volume was unchanged during the suspension period, whereas water consumption was decreased during suspension. Urinary excretion of corticosterone and catecholamines increased significantly during the initial 3 days of suspension. The excretion of antidiuretic hormone increased throughout the suspension period. Our results demonstrated that the determination of urinary excretion of these hormones is useful for evaluating the stress reaction.
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PMID:Urinary excretion of stress hormones of rats in tail-suspension. 1226 50

The aim of the present study was to determine the effect of social stress and significance of prostaglandins (PG) generated by constitutive and inducible cyclooxygenase (COX-1 and COX-2) in the stimulation of hypothalamic-pituitary-adrenal (HPA) axis by corticotropin releasing hormone (CRH) under basal and social crowding stress conditions. The stressed rats were crowded in groups of 24 to a cage for 3 or 7 days, whereas the control animals were haused in groups of 7 to a cage of the same size. The activity of HPA axis was determined by measuring plasma ACTH and serum corticosterone levels 1 h after i.p. CRH administration. Inhibitors of COX-1, piroxicam (0.2, 2.0, and 5.0 mg/kg), and COX-2, compound NS-398 (0.2 and 2.0 mg/kg), were administered i.p. 15 min prior to CRH (0.1 microg/kg i.p.) to control or crowded rats. The obtained results indicate that social stress for 3 and 7 days markedly intensifies the stimulatory action of CRH on ACTH secretion. Neither piroxicam nor NS-398 induce any significant effect on the CRH-elicited ACTH and corticosterone secretion in non-stressed or crowded rats. Therefore, PG generated by COX-1 or COX-2 do not participate to a significant extent in the stimulation of HPA axis by CRH under either basal conditions or during crowding stress. These results also indicate that the stimulatory action of CRH on ACTH secretion is not only completely resistant to desensitization but is sensitized during social crowding stress. The results contrast with a significant involvement of PG in the vasopressin-induced stimulation of HPA response during crowding stress.
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PMID:Effect of cyclooxygenase inhibitors on the CRH-induced pituitary-adrenocortical activity during crowding stress. 1267 22

The role of vasopressin, cosecreted with corticotropin-releasing hormone (CRH), in stress is debated, because both normal as well as reduced adrenocorticotropin hormone (ACTH) rise to an acute challenge has been reported in Brattleboro rats genetically lacking vasopressin (di/di). Because di/di pups could be born either from di/+ (heterozygous) or from di/di mothers, and maternal influence is known to modify adult responsiveness, we investigated whether the influence of maternal genotype could explain the variability. Adult rats from mothers with different genotypes were stressed with 60 min restraint and trunk blood was collected for measuring hormone content by radioimmunoassay at the end of stress. All offspring of di/+ mothers had similar ACTH responses to restraint, while the di/di rats born to, and raised by di/di mothers showed reduced ACTH reactivity to restraint. The di/di rats showed elevated water turnover and required a daily cage cleaning every day, which meant frequent handling. To offset the role of handling, all rats had daily cage cleaning in the next series, but the results were the same as in the first series. To investigate whether lactation, the behaviour of the mother or some other factor during the pregnancy is responsible for the differences, pups from di/+ dams were raised by di/di foster mothers and vice versa. We found that the genotype of parental mother is more important than that of the foster mother. The corticosterone and prolactin elevation normally seen after acute stress was unchanged by family history, maternal or personal genotype. Furthermore, in studies with mutant animals, the rearing conditions should be controlled by the experimenter. In experiments with Brattleboro rats, the use of homozygous and heterozygous rats from the same litters of di/+ dams and di/di males is recommended. Our results suggest that vasopressin is not indispensable for ACTH release, and that the di/di genotype of the parental mother can decrease the stress reactivity of the di/di Brattleboro rats.
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PMID:Maternal genotype influences stress reactivity of vasopressin-deficient brattleboro rats. 1463 71

In mouse kidney, the conventional protein kinase C (PKC) isoenzyme alpha is expressed in glomeruli, the cortical collecting duct (intercalated cells only), and medullary collecting duct. To get insights on its function, PKC-alpha knockout (-/-) and wild-type (+/+) mice were studied. When provided free access to water, PKC-alpha -/- mice showed approximately 50% greater urine flow rate and lower urinary osmolality in 24-h metabolic cage experiments despite a greater urinary vasopressin-to-creatinine ratio vs. PKC-alpha +/+ mice. Renal albumin excretion was not different. Clearance experiments under inactin/ketamine anesthesia revealed a modestly reduced glomerular filtration rate and showed a reduced absolute and fractional renal fluid reabsorption in PKC-alpha -/- mice. The sodium-restricting response to a low-sodium diet was unaffected in PKC-alpha -/- mice. Urinary osmolality was reduced to similar hypotonic levels in PKC-alpha -/- and +/+ mice during acute oral water loading or application of the vasopressin V(2)-receptor antagonist SR-121463. In comparison, the lower urinary osmolality observed in PKC-alpha -/- mice vs. wild-type mice under basal conditions persisted during water restriction for 36 h. In conclusion, PKC-alpha appears not to play a major role in renal sodium reabsorption but, consistent with its expression in the medullary collecting duct, contributes to urinary concentration in mice. Considering that PKC-beta I and -beta II are coexpressed with PKC-alpha in mouse medullary collecting duct, the present results indicate that conventional PKC isoenzymes cannot fully compensate for each other.
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PMID:Evidence for a role of protein kinase C-alpha in urine concentration. 1503 42

We used a phytoestrogen (PE) and a phytoestrogen-free (PE-Free) diet to determine whether or not diet can have neurobehavioral effects on intermale aggression in Syrian hamsters (Mesocricetus auratus). In Experiment 1, 20 adult male hamsters were pre-tested for aggression and then placed on a PE (n=10) or a PE-Free diet (n=10) for 4 weeks in isolation. During week 5, experimental hamsters were exposed to a group-housed, nonaggressive opponent (NAO) for 5 min in a neutral cage arena. PE-fed hamsters exhibited more attacks (33.4+/-6.1) toward the NAO compared to the PE-Free-fed hamsters (18.1+/-4) (p<0.05). Interestingly, testosterone in the blood serum was higher in the PE-fed group (11.01+/-1.48 ng/ml) compared to the PE-Free group (6.5+/-0.87 ng/ml). In Experiment 2, 16 juvenile hamsters were weaned onto a PE (n=8) or a PE-Free diet (n=8). After 7 weeks on the diet, experimental hamsters were exposed to a NAO for 5 min in a neutral cage arena. Although the PE group exhibited higher levels of aggressive behavior, there were no statistically significant differences between groups. However, the PE group had higher levels of testosterone (9.0+/-0.95 ng/ml) compared to the PE-Free group (4.6+/-0.98 ng/ml) (p<0.05). In addition, analysis of the brains from both experiments revealed differences in binding for vasopressin 1A (V1A) receptors. Optical densities were converted to disintegrating units per min/mg. The PE-Free group had higher levels of V1A receptor binding (2689.93+/-254.8 dpm/mg) compared to the PE group (1907.32+/-136.3 dpm/mg) in the lateral septum (p<0.05). In addition, there were differences in the lateral hypothalamus, but the PE group had higher receptor binding (2550.9+/-63.59 dpm/mg) when compared to the PE-Free group (2011.9+/-174.14 dpm/mg) (p<0.05). In sum, these data present the first evidence that phytoestrogens can affect aggressive behavior and, concurrently, alter hormonal status and stimulate changes in the brain of male hamsters.
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PMID:The neurobehavioral effects of phytoestrogens in male Syrian hamsters. 1523 58

Body fluid regulation is affected by gravity. The primary mechanisms of the etiology of hypovolemia found in simulation studies on earth and after space flight are different. The increased diuresis after increase of central blood volume postulated by Henry Gauer could not be found. Based on recent findings, new hypotheses about fluid volume regulation during space flight have emerged. The reduced blood volume in space is the result of 1) a negative balance of decreased fluid intake and smaller reduction of urine output; 2) fast fluid shifts from the intravascular to interstitial space as the result of lower transmural pressure after reduced compression of all tissue by gravitational forces especially of the thorax cage; and 3) fluid shifts from intravascular to muscle interstitial space because of less muscle tone required to maintain body posture. Additionally, loss of erythrocytes reduces blood volume. The attenuated diuresis during space flight can be explained by increased retention after stress-mediated sympathetic activation during initial phase of space flight, stimulation caused by reduced red cell mass, and activation after fast blood volume contraction. Additionally, the relation between plasma osmolarity and vasopressin release might be disturbed in microgravity.
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PMID:Plasma and blood volume in space. 1763 May 98


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