Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of nonapeptide hormones and some of their chemical analogues on progesterone and testosterone production by culture of porcine granulosa cells have been investigated. Oxytocin (0.01-10 IU/ml), arginine-8-vasopressin (0.01-10 micrograms/ml), arginine-8-vasotocin (0.01-10 micrograms/ml) and, in a lesser degree, 2-0-methyl-tyrosine (deamino-1-karba)-oxytocin (0.01-10 micrograms/ml, but no 1-deamino-8-vasopressin (0.01-10 micrograms/ml) stimulated a progesterone surge. Testosterone production was significantly stimulated by oxytocin and inhibited by vasopressin or vasotocin additions. 2-0-methyl-tyrosine (deamino-1-karba)-oxytocin or 1-deamino-8-vasopressin had little or no effect on testosterone secretion. The present results suggest the existence of a direct influence of nonapeptide hormones on porcine ovarian progestagen and androgen production.
 ...
PMID:The influence of oxytocin, vasopressin and their analogues on progesterone and testosterone production by porcine granulosa cells in vitro. 144 77

A single dose of des-glycinamide-[Arg8]vasopressin (DGAVP, 2 mg intranasal) or oxytocin (OXT, 20 IU intranasal) was given to female and male volunteers, respectively, in a placebo-controlled double-blind trial. Memory, vigilance, attention, and mood were tested starting 10 minutes after treatment. The DGAVP dose improved delayed recognition of abstract words when measured 1 week after treatment and reduced the intercept of a memory comparison task (Sternberg paradigm). A trend was present for DGAVP and OXT to affect learning, i.e., storage processes of verbal memory in an opposite way; DGAVP improved, while OXT attenuated initial storage and the rate of storage. No treatment effects on visual memory and vigilance were found. Of the mood measures, vigor was reduced immediately after treatment with OXT.
 ...
PMID:Effect of a single dose of des-glycinamide-[Arg8]vasopressin or oxytocin on cognitive processes in young healthy subjects. 152 61

We measured net K+ fluxes in the isolated toad urinary bladder to determine whether neurohypophyseal hormones control K+ secretion in this tissue. To determine if the pathway involved in K+ secretion is similar to a Ca(2+)-blockable alkali cation channel in the apical membrane of toad bladder, previously described in electrophysiological studies, we measured K+ fluxes in either the presence or absence of Ca2+ in the mucosal bathing solution. Oxytocin enhanced K+ secretion in both cases; however, the enhancement was markedly greater in the absence of mucosal Ca2+. In other experiments the transepithelial voltage was held constant at a value of 120 mV (mucosa negative) to find whether hyperpolarization would enhance K+ secretion to the levels seen in Ca(2+)-free solutions. The response to oxytocin was markedly greater in the absence of mucosal Ca2+ even when the transepithelial voltage was continuously hyperpolarized. These observations suggest that the properties of the activated pathway are akin to those of the previously described Ca(2+)-blockable alkali cation channel. We also found that toad bladder urine often contained extremely low levels of Ca2+; therefore neurohypophyseal hormonal control of K+ transport across the bladder may play an important role in amphibian K+ balance.
 ...
PMID:Urinary Ca2+ and the regulation of K+ secretion in toad bladder by neurohypophyseal hormones. 155 61

Studies performed in conscious female rats confirmed that iv injection of cholecystokinin octapeptide (CCK; 20 mu/kg) increased the circulating concentration of oxytocin but not that of vasopressin, and confirmed that the stimulation of oxytocin release was markedly facilitated after iv administration of naloxone (1 mg/kg), indicating attenuation of oxytocin release by endogenous opioids. To investigate the site of action of the endogenous opioids, the electrical activity of putative oxytocin neurones in the supraoptic nucleus was recorded in urethane-anaesthetised female rats. Oxytocin neurones responded to CCK injection with an increase in firing rate lasting 5-15 min, but this response was not facilitated by prior injection of naloxone. The results suggest that the opioid influence upon CCK-induced oxytocin release operates at the level of the neurosecretory terminals in the neurohypophysis rather than centrally. Since CCK does not elevate vasopressin release, it appears unlikely that dynorphin, the opioid peptide co-existing with vasopressin, is responsible in these circumstances for the cross-inhibition of oxytocin release. It is suggested that products of proenkephalin A, the met-enkephalin precursor present in the supraoptic nucleus and in the neurohypophysis itself, may be active in the regulation of oxytocin release.
 ...
PMID:Naloxone potentiates the release of oxytocin induced by systemic administration of cholecystokinin without enhancing the electrical activity of supraoptic oxytocin neurones. 157 6

Peripheral administration of vasopressin (VP) was previously shown to exert a negative feedback influence on its own release and on the release of oxytocin (OT). In this study we examined the possible influence that OT has on the function of hypothalamic magnocellular neurones. Oxytocin was administered intraperitoneally and its effects on release from VP neurones and from OT neurones were determined as indexed by plasma concentrations of vasopressin-associated neurophysin ([VP-RNP]) and oxytocin-associated neurophysin ([OT-RNP]) under basal conditions and conditions of high plasma osmolality (Posm) induced by acute salt loading. Studies were performed on conscious, chronically instrumented Long-Evans rats. Oxytocin (1 nmol or 10 nmol) dissolved in 1 mL of 0.9% saline was administered intraperitoneally to animals 1 h before they received an intravenous infusion of hypertonic saline over 60 min at a rate designed to raise Posm by approximately 0.75 mosmol.min-1. Intraperitoneal injection of vehicle or 1 nmol of OT did not significantly alter [VP-RNP], [OT-RNP], or basal Posm. Administration of 10 nmol OT also had no effect on [VP-RNP] or [OT-RNP], but this dose of peptide significantly lowered basal Posm (299 +/- 2 to 290 +/- 2 mosmol/kg H2O, p less than 0.001). Both doses of OT did not significantly alter the responsiveness of VP neurones to hyperosmotic stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Absence of negative feedback by oxytocin on release from magnocellular neurones in conscious rats. 158 42

Sites which bind oxytocin and vasopressin with high affinity were detected in the brain and upper spinal cord of 12 human subjects, using in vitro light microscopic autoradiography. Tissue sections were incubated with tritiated vasopressin, tritiated oxytocin or an iodinated oxytocin antagonist. The ligand specificity of binding was assessed with unlabelled vasopressin or oxytocin in excess, as well as in competition experiments using synthetic structural analogues. The distribution of vasopressin binding sites differed markedly from that of oxytocin binding sites in the forebrain, while there was overlap in the brainstem. Vasopressin binding sites were detected in the dorsal part of the lateral septal nucleus, in midline nuclei and adjacent intralaminar nuclei of the thalamus, in the hilus of the dentate gyrus, the dorsolateral part of the basal amygdaloid nucleus and the brainstem. The distribution of oxytocin binding sites in the brainstem has been recently reported (Loup et al., 1989). Oxytocin binding sites were also observed in the basal nucleus of Meynert, the nucleus of the vertical limb of the diagonal band of Broca, the ventral part of the lateral septal nucleus, the preoptic/anterior hypothalamic area, the posterior hypothalamic area, and variably in the globus pallidus and ventral pallidum. The presence of oxytocin and vasopressin binding sites in limbic and autonomic areas suggests a neurotransmitter or neuromodulator role for these peptides in the human central nervous system. They may also affect cholinergic transmission in the basal forebrain and consequently play a role in Alzheimer's disease.
 ...
PMID:Localization of high-affinity binding sites for oxytocin and vasopressin in the human brain. An autoradiographic study. 165

Oxytocin (OT) and V1 vasopressin (VP) receptors are present simultaneously in several tissues, including the uterus. In myometrium these receptors mediate contractility, while in endometrium they mediate the release of other uterotonic substances as endothelin (ET). In rabbit myometrium, estrogens increase, while progesterone blunts neurohypophysial hormone receptors. However, the action of sex steroids on OT and V1 VP receptors differs in terms of the ED50 and maximal effect. Therefore, at parturition, only OT receptors show a dramatic rise, while V1 VP receptors do not change, suggesting a major role for OT in labor. ET is a potent stimulator of uterine activity acting through specific receptors present on myometrial cells. These receptors as well as the endometrial localization of ET are modulated by sex steroids, indicating that ET might represent a paracrine regulator of uterine activity. In humans, OT but not V1 VP receptors increase as pregnancy progresses, confirming the primary relevance of OT in timing delivery.
 ...
PMID:Steroid modulation of oxytocin/vasopressin receptors in the uterus. 165 85

Previous studies of marsupial lactation have shown that the milk-ejection reflex changes in sensitivity, being greater in small mammary glands sucked by small pouch young and lesser in larger glands supplying milk to larger young. The involvement of oxytocin receptors in these changes was examined in the brushtail possum Trichosurus vulpecula. Oxytocin receptors were measured in the mammary glands, uterus, and medial vaginal sacs by radioreceptor assay, using [3H]oxytocin as radioligand. In the mammary gland, a single oxytocin binding site was found with an affinity and receptor concentration of 0.81 +/- 0.41 l/nmol and 10.2 +/- 4.8 pmol/g tissue respectively (SD, 10 possums). Competitive displacement curves with related peptides and analogs showed the following order of specificity: d(CH2)5[Tyr(Me)2,Thr4,Tyr9-NH2]-vasotocin much greater than vasotocin greater than oxytocin = Arg-vasopressin greater than mesotocin greater than [Thr4,Gly7]-oxytocin = Lys-vasopressin greater than [deamino-Pen1, O-methyl-Tyr2, Arg8]-vasopressin greater than isotocin much greater than [d(CH2)5, D-Phe2, Ile4, Ala9-NH2]-AVP. [3H]Oxytocin did not bind to vasopressin receptors in the thoracic aorta. The concentration of oxytocin receptors was very high in small mammary glands (18.6 pmol/g tissue in a 2-g gland) and decreased logarithmically as the size of the mammary gland increased. It is suggested that the changes in the sensitivity of milk ejection to oxytocin is related to the concentration of mammary oxytocin receptors. The presence of oxytocin receptors in both uterus and median vaginal sacs extends previous observations and supports the hypothesis that in marsupial parturition, the uterus and medial vaginal sacs respond as a single functional unit to oxytocin.
 ...
PMID:Oxytocin receptors in the mammary gland and reproductive tract of a marsupial, the brushtail possum (Trichosurus vulpecula). 166 15

Social recognition of juvenile rats by adult male residents has been shown to be modulated by peripheral administration of neurohypophyseal hormones vasopressin and oxytocin. In the present study, the effects of these peptides on social recognition were investigated after local injection into the medial preoptic area of the hypothalamus. It was found that oxytocin given in a wide range of doses (0.3-1000 pg) facilitated social recognition. This effect was not blocked by pretreatment with oxytocin receptor antagonist desGly(NH2)9-d(CH2)5[Tyr(Me)2Thr4]OVT. Oxytocin injected into the septum in doses of 0.03-3 pg was not effective. Administration of vasopressin (100 or 1000 pg), [pGlu4,Cyt6]AVP-(4-8) (200 pg) or [pGlu4,Cyt6]AVP-(4-9) (200 pg) into the medial preoptic area did not influence social recognition. It is concluded that the medial preoptic area is a sensitive brain site for the oxytocin-induced facilitation of social recognition in rats.
 ...
PMID:Oxytocin but not vasopressin facilitates social recognition following injection into the medial preoptic area of the rat brain. 166 16

Hypothalamic magnocellular neurons of the paraventricular and supraoptic nuclei contain several peptides and non-peptide putative neurotransmitters co-existing with vasopressin and oxytocin. However, the functional role of these substances is still unknown. In the present paper the temporal course of changes in the expression of vasopressin, oxytocin, galanin, cholecystokinin, dynorphin and tyrosine hydroxylase in magnocellular hypothalamic neurons of rats subjected to hypophysectomy was examined. Following different survival times the animals were processed either for immunohistochemistry with antibodies against the above mentioned peptides or for in situ hybridization with synthetic oligonucleotide probes complementary to the mRNAs encoding for the peptides. The results obtained showed a marked rise in vasopressin mRNA levels at two days followed by a decrease up to 36 days of survival. Oxytocin mRNA responded to the lesion with a transient decrease, with its lowest values between five and seven days. This was followed by a recovery which almost reached normal values at 36 days of survival. The results also showed a marked, transient activation of the synthetic pathway for galanin and cholecystokinin. The numbers of cells expressing these peptides were maximal between five and seven days, and the respective mRNA levels were significantly increased at these survival times. This was followed by a decrease in the amount of galanin- and cholecystokinin-like immunoreactivity as well as in the levels of their respective mRNAs. Dynorphin-like immunoreactivity showed a course similar to that of galanin and cholecystokinin in operated animals. However, the amounts of dynorphin mRNA were significantly increased at two days, but were followed by a reduction at five days and remained low throughout the different survival times tested. The experiments performed with the tyrosine hydroxylase antibodies and probe showed undetectable levels of the enzyme and its mRNA in normal and hypophysectomized animals. These results demonstrate that, in magnocellular hypothalamic neurons, expression of several peptides occur in differential ways after hypophysectomy. The possibility is discussed that these changes represent part of the mechanisms underlying the process of degeneration and regeneration known to occur in magnocellular hypothalamic neurons after hypophysectomy.
 ...
PMID:Neuropeptide gene expression in hypothalamic magnocellular neurons of normal and hypophysectomized rats: a combined immunohistochemical and in situ hybridization study. 169 57


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>