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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of ethanol and acetaldehyde on the release of arginine-vasopressin (AVP) and oxytocin (OXT) were examined using a superfusion system of the isolated hypothalamo-hypophyseal complex of rats. The release of both hormones was significantly suppressed by exposing the tissue samples to Eagle MEM medium containing 1.75 and 2.5% ethanol (the maximal suppression: AVP, 30% and 70%; OXT, 30% and 70%, respectively). However, perfusion with medium containing 3.75 and 5.0% ethanol enhanced the release of OXT during exposure to ethanol (the maximal increase, 1,000%) and the release of AVP was increased markedly just after exposure to ethanol was stopped (the maximal increase, 800%). Perfusion with medium containing 50, 100 and 250 microM acetaldehyde did not affect the release.
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PMID:Effect of ethanol and acetaldehyde on the release of arginine-vasopressin and oxytocin from the isolated hypothalamo-hypophyseal system of rats. 408 11

This study evaluates the efficacy of prostaglandin E2 (PGE2) as an oxytocic agent for the augmentation of delay in labor in 40 consecutive patients matched with another group of 40 patients (treated with intravenous oxytocin) as to age, parity, maturity, cervical dilation at time of augmentation, and analgesia. Delay in labor was diagnosed clinically when there was arrest in the descent of the presenting part and/or arrest of dilatation of the cervix. All patients were continuously monitored by means of a presenting part electrode and an intrauterine pressure catheter. Both oxytocin and PGE2 were administered via a constant infusion Palmer pump. Standard dosage increments were used until adequate contractions were achieved and no deleterious effect on the fetus was observed. 0.75 ml of 1 mg/ml ampoule of PGE2 in ethanol was diluted in 500 ml normal saline. Initial rate of infusion was 0.285 mcg/minute for a minimum of 30 minutes; the dose was subsequently doubled at intervals of 1 hour until adequate contractions were achieved. Initial rate for infusion for oxytocin was 2mu/minute; the dose was doubled every hour until adequate contractions were noted. Further cervical dilatation and descent of the presenting part occurred in all cases. Mean Apgar scores at 1 and 5 minutes respectively were 7.53 and 9.50 for the PG group, and 6.93 and 9.18 for the oxytocin group. No perinatal deaths occurred. Mean birthweight was 3.34 kg for the PG group and 3.39 kg for the oxytocin group. The oxytocin group exhibited significantly higher augmentation/delivery interval (7.32 hours vs. 5.2 for the PG group, p 0.001), mean basal uterine tone (13.23 vs. 7.38, p 0.001), mean frequency of contraction (4.39 vs. 3.61, p 0.01), and incidence of side effects (nausea, vomiting, and pyrexia). A fetal heart rate of less than 100 beats/minute was seen in 3 patients in the PG group and 7 in the oxytocin group.
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PMID:A comparison of intravenous prostaglandin E2 and intravenous oxytocin for the augmentation of labour complicated by delay. 445 29

A clinical test was conducted with 40 healthy women 2-8 days following parturition to assess the effect of ethanol on the milk-ejecting reflex. The women before they were given alcohol were used as their own controls. The inhibition was found to be better correlated with the dose of ethanol administered than with the blood alcohol concentration measurement conducted at the end of the experiment. Results are tabulated and graphed. Ethanol in doses from .5-.93 gm per kilogram produced significant inhibition of the milk-ejecting activity; in doses from 1-1.48, there was an inhibition of the response to suckling; in doses from 1.5-1.9, the strongest inhibition was observed. The study, thus, confirms earlier findings that ethanol blocks oxytocin release. The effect was widely variable but definitely dose-related. It is possible that doses higher than 2 gm per kilogram could completely inhibit the suckling-induced oxytocin release which controls milk-ejecting activity.
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PMID:Effect of different doses of ethanol on the milk-ejecting reflex in lactating women. 468 84

Identifying posterior pituitary hormones in body fluids or neurohypophysial extracts was heretofore partially achieved by using pharmacologic potency ratios or semispecific inactivation by thioglycolate or enzymes. Production of antisera against oxytocin and lysine-vasopressin has prompted us to test their specificity against lysine-vasopressin, arginine-vasopressin, arginine-vasotocin, and oxytocin. In ethanol anesthetized rats, antidiuretic and milk-ejection activities were assayed for each peptide-antiserum combination after 0, 30, 60, and 90 min of incubation. Results indicate that (a) oxytocin antiserum inactivates oxytocin, but not arginine-vasopressin, lysine-vasopressin, or arginine-vasotocin; vasopressin antiserum inactivates arginine-vasopressin and lysine-vasopressin, but neither oxytocin nor arginine-vasotocin; (b) an identifiable antigenic site exists for each hormone; (c) relatively specific identifications of natural neurohypophysial peptides are possible using antisera and bioassays; (d) this method is promising for identifying neurohypophysial peptides in body fluids and pituitary extracts; and (e) active and passive immunization against oxytocin and vasopressin may increase our understanding of their physiologic functions.
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PMID:Identification of neurohypophysial hormones with their antisera. 544 83

In the present work an attempt is made to get a deeper insight into the mechanism of labor and the events leading to the onset of labor by means of radioimmunological measurements of OT, PGE, PGF, PGEM and PGFM and by determining the oxytocin sensitivity and the concentration of oxytocin receptors. Prostaglandins play a major role for the mechanism of labor in labor of spontaneous onset as well as in several forms of induced labor (intravenous infusion of OT, amniotomy, local application of PGE2). The reason for this seems to be the 3 fold action of prostaglandins: stimulation of myometrial contractions, cervical softening, induction of gap junctions. Moreover prostaglandins produced in the placenta play a major role in the mechanism of placental separation and expulsion. Oxytocin seems to be of importance for the initiation of labor and the final expulsion of the fetus. Immediately before the onset of regular contractions a marked increase of oxytocin sensitivity can be demonstrated which correlates very well with an increase of oxytocin receptor concentration in the myometrium and decidua. Due to this increase in oxytocin sensitivity no rise in oxytocin plasma levels is necessary to induce labor. Apart from the induction of myometrial contractions oxytocin leads via receptors in the decidua to a stimulation of prostaglandin synthesis which can also be demonstrated in vitro. In cases of premature contractions the same mechanisms seem to be operational as at term, oxytocin and prostaglandins again playing a major role. Inhibition of contractions with ethanol is based on the capacity of alcohol to inhibit oxytocin secretion. The contractions inhibiting effect of ritodrine is mediated through the cAMP induced relaxation of the myometrium although possibly a direct reduction of prostaglandin synthesis by ritodrine is possible. Increasing estrogen and decreasing progesterone activities at term lead to multiple subtile changes leading to an increased prostaglandin synthesis and mainly to a rise in oxytocin receptor concentration in the myometrium and the decidua. Oxytocin from the fetal and maternal side stimulates contractions in the myometrium and prostaglandin synthesis in the decidua leading to the onset of labor. With progressing cervical dilatation prostaglandin synthesis is further stimulated; these prostaglandins together with the increased oxytocin plasma levels in the second stage of labor lead to expulsion of the fetus. After delivery prostaglandin synthesis in the placenta leads to placental separation and expulsion.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[The importance of oxytocin and prostaglandins to the mechanism of labor in humans]. 609 5

Extracts of bovine neurohypophysis made in acid/ethanol solution containing protease inhibitors were fractionated by two successive filtrations on Sephadex G-75 columns equilibrated in the presence and then in the absence of 4 M urea. Analysis of the pattern of neurophysin-like immunoreactivity in the eluate, with two different antibodies, indicated the presence of high M(r) forms of neurophysin (apparent sizes, [unk]70,000 and 20,000-25,000, respectively) besides the M(r) 10,000 neurophysin. [8-Arginine]vasopressin-like immunoreactivity was also detected, coeluting with the neurophysin-like species, in the material recovered in the exclusion and M(r) 20,000-25,000 elution volumes of the same molecular sieve fractionation of neurohypophyseal extracts. Upon subsequent Sephadex G-150 filtration, the immunoreactive material recovered in the exclusion volume of the Sephadex G-75 filtration showed an apparent M(r) of approximately 140,000. Both neurophysin-like and vasopressin-like immunoreactivities coeluted in the same volume. The elution profile of this M(r) 140,000 material was unmodified when reanalyzed by the same molecular sieve filtration after exposure to 8 M urea. When these M(r) 140,000 immunoreactive forms of vasopressin and neurophysin were submitted to affinity chromatography on anti-neurophysin antibodies immobilized on Sepharose, both immunoreactivities were selectively coadsorbed to the immunoadsorbent. Similarly, the neurophysin and vasopressin immunoreactivities associated with M(r) approximately 25,000 were retained together on the same anti-neurophysin immunoadsorbent. The M(r) 140,000 and M(r) 25,000 species having both neurophysin and [8-arginine]vasopressin antigenic determinants generated the two neurosecretory components when exposed to proteolytic activities. This in vitro processing was inhibited in acid medium, at low temperature, and in the presence of a mixture of protease inhibitors. It is concluded that these two large forms of proteins containing both neurophysin and vasopressin may represent common biosynthetic precursors of these two neurohypophyseal components.
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PMID:Immunological identification of high molecular weight forms common to bovine neurophysin and vasopressin. 615 53

Oxytocin neurotropic qualities were investigated in "reserpine depression" tests under ethanol and levomepromazine anesthesia, phenamine depression, haloperidol catatonia and swimming of experimental animals in the cylinder. Twenty seven patients with schizophrenia were treated with the hormone mentioned, injected intravenously and/or intranasally, using a double blind control test. The activating psychotropic oxytocin effects were revealed, allowing one to utilize it as a therapeutic means for psychosis treatment.
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PMID:[Psychotropic properties of oxytocin]. 671 33

Experiments were conducted to investigate the dose-related and time-dependent effects of oxytocin on memory for a one-trial conditioned taste aversion task using two-day old chicks. Oxytocin was administered intracerebrally 1 min posttraining to 5 groups of chicks in dose levels differing by a factor of 10 and ranging from 5.0 pg to 50 ng. A second experiment tested the time-dependent nature of the neuropeptide's action. In this experiment the oxytocin (5.0 ng) was administered at either 1 min, 9 min or 59 min posttraining. In both experiments saline-injected control groups were included. The taste aversion training for all experiments consisted of presenting an attractive lure, coated with an aversive liquid (EtOH), to each chick for a 10-s training trial. Most chicks pecked 1 or 2 times at the lure before inhibiting any further response. The retention testing took place 24 h after the training and consisted of presenting the dry, uncoated lure to each chick for an additional 10 s. Chicks that avoided pecking at the lure were considered to have exhibited enhanced retention. The groups of chicks receiving 50 pg to 50 ng of oxytocin exhibited enhancement of retention, as did the 1 min group of the time-dependent experiment. These results are compared to the effects on memory consolidation in chicks induced by vasopressin and L-prolyl-L-leucyl-glycineamide. The apparent conflict between these results and those obtained in mammalian studies with oxytocin are discussed.
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PMID:Dose-dependent and time-dependent action of oxytocin on chick memory. 687 71

It is well documented that children with the fetal alcohol syndrome are a direct consequence of heavy maternal ethanol consumption during pregnancy. The mechanism by which ethanol exerts its teratogenic effect is however, far from understood. Recent experimental evidence has shown alcohol to have a direct inhibitory effect on embryogenesis. Little information, however, is available concerning other factors associated with maternal drinking which may contribute to abnormal fetal development. Proper materno-fetal hormonal balance is essential to insure successful pregnancy outcome. Of particular importance with respect to normal fetal development, are the levels of placental tropic hormones; pituitary hormones such as prolactin and oxytocin; adrenal cortical hormones; both maternal and fetal thyroid hormones; maternal and fetal sex hormones; and maternal insulin. Ethanol alters the levels of a variety of hormones associated with the hypothalamic/pituitary-gonadal, -adrenal and -thyroid axes. Many of these alterations have been observed in the male, however, with little data available on the female. In spite of the known adverse effect of ethanol on certain aspects of female reproductive function, few if any studies have examined the effects of alcohol ingestion during pregnancy on maternal endocrine balance. It is hoped that the present review will provide a rationale for the examination of alcohol effects on maternal endocrine hormones, as well as to provide possible target areas with respect to fetal development subsequent to ethanol-induced endocrine imbalance.
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PMID:Endocrine balance as a factor in the etiology of the fetal alcohol syndrome. 701 43

The plasma antidiuretic activity and the content of antidiuretic hormone (ADH) and oxytocin of the neurointermediate lobe were determined in male rats under normal conditions and after copulation. The plasma samples from control rats assayed directly in the water-loaded ethanol-anaesthetized rat had no detectable antidiuretic activity. The same negative result was observed in plasma obtained from male rats during courtship. However, plasma obtained from male rats at different time intervals after copulation had an antidiuretic activity which was maximal one h after ejaculation. When the ADH was extracted from pools of plasma samples, the circulating level of the hormone in control rats was also measured. The plasma antidiuretic activity after copulation was abolished after thioglycolate treatment which inactivates the neurohypophysial hormones. These findings suggest that ADH is released after copulation and that such a release is maintained for at lest 60 min.
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PMID:The effect of copulation on the plasma antidiuretic activity of the male rat. 706 57


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