Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human placental leucine aminopeptidase (P-LAP) was purified from retroplacental serum for the first time by serial chromatography on columns of Matrex Blue A, DEAE-Sepharose CL-6B, phenyl-Sepharose 4B, chelating-Sepharose, and Sepharose CL-6B. The purified P-LAP was apparently homogeneous on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the apparent molecular weight (Mr) was estimated to be 210,000. By comparing P-LAP activity with cystine aminopeptidase activity, we concluded that both activities were shared by the same molecule. We also examined the hydrolytic activity of P-LAP using naturally occurring peptide hormones and found that the enzyme hydrolyzed oxytocin, vasopressin, and angiotensin III. These results suggest that P-LAP shows oxytocinase activity and plays an important role in the regulation of the plasma level of these hormones during pregnancy.
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PMID:Identification of human placental leucine aminopeptidase as oxytocinase. 173 8

Gastric acid output was examined following oxytocin injection into the hypothalamic paraventricular nucleus (PVN) or into the vagus nucleus (X) of the medulla in rats with insulin-hypoglycemia. Gastric acid output was reduced following the injection of nanomolar quantities of oxytocin into these nuclei, and the response was dose-dependent. It was also noted that there was a synergistic action on the response by the peptide between PVN and X. The acid response was blocked by section of the vagus nerve at the subdiaphragmatic level or by prior administration of atropine sulfate. These observations suggest that oxytocin in the PVN is active in suppressing gastric acid secretion, and the vagal response is characteristic of activation of the PVN and X.
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PMID:Secretion of gastric acid inhibited by oxytocin injected into the hypothalamic paraventricular nucleus in the rat. 176 66

A bovine neurophysin II S-methyl-Cys-Tyr-Phe-NH2 complex has been crystallized using ammonium sulfate as the precipitating agent. The crystals are orthorhombic, the space group is either I222 or I2(1)2(1)2(1) with a = 124.9 A, b = 69.6 A and c = 151.5 A. The crystals diffract to at least 3.0 A resolution. Based on one neurophysin tetramer per asymmetric unit, the Matthews coefficient is calculated to be 3.92 with a solvent content of 69%.
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PMID:Crystals of a bovine neurophysin II tripeptide complex. 194 66

The effect of severity of hypertension on fetal heart rate tracing changes and neonatal outcomes was evaluated on all patients with hypertension seen in 1980 and 1981 (666 cases, 10% of the pregnant population) in the Chicago-Lying In Hospital. The patients were grouped according to severity of hypertension, and the fetal heart rate monitoring, drugs administered, mode of delivery, and neonatal outcome were analyzed. Half of the patients (326) had mild hypertension and 13% (87) had severe hypertension; the remainder (253) had moderate hypertension. There were 49% primiparous and 51% multiparous women. The diagnosis of preeclampsia was made in 76% of cases, and chronic hypertension in 19%. Only 12% of the total were premature by dates, but 47% of this group were among the severe group. Oxytocin was given to 50%, whereas delivery was spontaneous in 56% of cases, and by cesarean section in 22%. This was higher among the severe hypertension group (37%), and the prematurity rate was 47%. Nonstress testing was done in one third of cases and only nonreactivity was associated with neonatal death. Neonatal depression (Apgar score less than 6 at 5 minutes) was significantly associated with intrapartum fixed baseline and late decelerations; these were the best predictors of fetal outcome. The administration of magnesium sulfate, hydralazine, meperidine, or morphine did not predictably affect the fetal heart rate pattern. The perinatal mortality was 21% in the mild group and 36% and 138%, respectively, among moderate and severe cases of hypertension. Close antepartum and intrapartum surveillance, including proper fetal monitoring, should help to reduce risks for mother and fetus through timely intervention.
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PMID:Effects of hypertension on pregnancy monitoring and results. 222 Sep 23

Magnesium sulfate has been shown in vivo and in vitro to decrease the frequency of uterine contractions while maintaining the amplitude; we therefore decided to assess the use of magnesium sulfate infusion in cases of uterine hyperstimulation. The medical records were reviewed retrospectively for 37 term pregnant patients diagnosed as having uterine hyperstimulation during labor. None of them had medical or obstetric complications. Twenty-two of them received oxytocin augmentation for abnormal labor. Although the vast majority of these patients had a decrease of the hyperstimulation while being given the magnesium, 31.8% in the group receiving oxytocin alone (P less than .05). Fifteen additional patients received magnesium sulfate for uterine hyperstimulation although they were not receiving oxytocin; of these, 16.7% required cesarean delivery. This rate was no different from that of the patients who required labor augmentation, but was double the overall primary cesarean rate at our hospital. There appears to be a group of patients with abnormal uterine activity (either spontaneous or associated with oxytocin augmentation) that responds to treatment with magnesium sulfate.
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PMID:Use of magnesium sulfate to treat hyperstimulation in term labor. 232 61

Outward rectifying, cation channels were observed in the epithelial cells of the urinary bladder of the toad. Bufo marinus. As studied in isolated cells using the patch-clamp technique, the channel has an average conductance of 24 and 157 pS for pipette potentials between 0 and +60 mV and -60 to -100 mV, respectively, when the major cation in both bath and pipette solutions is K+. The conductance of the channel decreases with increasing dehydration energy of the permeant monovalent cation in the order Rb+ = K+ greater than Na+ greater than Li+. Reversal potentials near zero under biionic conditions imply that the permeabilities for all four of these cations are similar. The channel is sensitive to quinidine sulfate but not to amiloride. It shares several pharmacological and biophysical properties with an outwardly-rectifying, vasopressin-sensitive apical K+ conductive pathway described previously for the toad urinary bladder. We demonstrate, in both single-channel and whole-bladder studies, that the outward rectification is a consequence of interaction of the channel with extracellular divalent cations, particularly Ca2+, which blocks inward but not outward current. Various divalent cations impart different degrees of outward rectification to the conductive pathway. Concentrations of Mg2+ and Ca2+ required for half-maximal effect are 3 X 10(-4) and 10(-4) M, respectively. For Co2+ the values are 10(-6) M at +50 mV and a 10(-4) M at +200 mV. The mechanism of blockade by divalent cations is not established, but does not seem to involve a voltage-dependent interaction in which the blocker penetrates the transmembrane electric field. In the absence of divalent cations in the mucosal solution, the magnitudes of inward current carried by Rb+, K+, Na+ and Li+ through the apical K+ pathway at any transepithelial voltage, are in the same order as in the single-channel studies. We propose that the cation channel observed by us in isolated epithelial cells is the single-channel correlate of the vasopressin-sensitive apical K+ conductive pathway in the toad urinary bladder and is also related to the oxytocin- and divalent cation-sensitive apical conductivity observed in frog skin and urinary bladder.
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PMID:Extracellular Ca2+ controls outward rectification by apical cation channels in toad urinary bladder: patch-clamp and whole-bladder studies. 246 99

An immunoblotting method to detect low-molecular-weight peptides with monoclonal antibodies that normally fail to demonstrate immunoreactivity using conventional blotting techniques is described. Detection of neurophysin, insulin, calcitonin, vasopressin, and beta-endorphin electroblotted on nitrocellulose membranes was optimized after introducing four modifications into the conventional procedure. These include renaturing the gels after sodium dodecyl sulfate electrophoresis, electroblotting the renatured gels in basic transfer buffer, fixing and/or heating the blots, and using avidin/alkaline phosphatase conjugates for antigen/antibody detection. This technique likely enables the denatured peptides to regain their native conformation and, therefore, restores antigenicity and recognition by highly structural specific monoclonal antibodies. Although the most dramatic improvement with this technique is with monoclonal antibodies, a modest improvement in sensitivity can be obtained when immunoblots are probed with polyclonal antibodies. The high resolution of this system will be useful in probing blots of partial proteolytic digests of proteins with both monoclonal and polyclonal antibodies.
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PMID:Detection of low-molecular-weight polypeptides on nitrocellulose with monoclonal antibodies. 269 85

Effects of Dehydroepiandrosterone-Sulfate (DHA-S) administration during the induction of labor were analysed comprehensively in 116 cases of primipara without any complications. In all of the patients delivery was induced by means of intravenous drip infusion of oxytocin. DHA-S was given as follows; Group A: no administration of DHA-S, Group B: intravenous drip infusion of 600 mg of DHA-S, Group C: intravenous injection of 200 mg of DHA-S every two hours (max, five times). The duration of the first and second stages of labor was reduced significantly in Group C compared to that of Group A (p less than 0.02). Serum DHA-S and estradiol levels in the patients in Groups B and C were significantly higher than those in Group A during the induction of the labor (p less than 0.05-0.005). The secretion of maternal milk was suppressed transiently by the administration of DHA-S (p less than 0.05-0.005), and there was a significant negative correlation between the total amount of maternal milk secretion and the total dose of DHA-S (r = -0.6320, p less than 0.005). Maternal serum prolactin levels did not change significantly following the administration of DHA-S, but estradiol increased significantly following the administration of DHA-S until 48 hours after delivery. These facts suggested that the intravenous injection of 200mg of DHA-S every two hours was effective in assisting the induction of labor, and the transient suppression of maternal milk secretion due to the administration of DHA-S might be caused by the high level of maternal serum estradiol which was converted from DHA-S in the placenta.
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PMID:[Comprehensive approach to the clinical study of the administration of dehydroepiandrosterone-sulfate (DHA-S) during the induction of labor]. 294 85

We have investigated the ability of tissue explants of human amnion, chorion, and decidua to produce estrone when incubated alone or in the presence of estrone sulfate, dehydroepiandrosterone, dehydroepiandrosterone sulfate, androstenedione, or testosterone. Amnion produced very little estrone from any substrate. Chorion utilized all substrates and decidua utilized estrone sulfate and dehydroepiandrosterone sulfate for estrone production. For both chorion and decidua, estrone sulfate was quantitatively the most important substrate. Chorionic tissues obtained after spontaneous labor produced greater levels of estrone than tissues obtained before labor (p less than 0.05). We could demonstrate no effect of cortisol, estriol, progesterone, prostaglandins, oxytocin, or dibutyryl cyclic adenosine monophosphate on estrogen production. We also measured endogenous concentrations of estrone and estradiol in fetal membranes. We found no significant difference in tissue concentrations between the two methods of delivery. There was no significant correlation between estrone and estradiol concentrations and distance from the placenta. We conclude that human chorion and decidua can produce estrogen, which may have some role in determining the timing of parturition.
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PMID:Substrate utilization for estrogen synthesis by human fetal membranes and decidua. 294 68

Administration of lithium chloride, copper sulfate, and apomorphine to rats each stimulated the secretion of oxytocin (OT) and, to a much lesser degree, arginine vasopressin. These agents are assumed to cause visceral illness in rats because of their effectiveness in promoting the acquisition of learned taste aversions. CuSO4 had a greater effect on plasma OT levels when administered ip rather than iv, whereas LiCl did not, results suggesting that LiCl probably stimulates OT secretion by central chemoreceptor activation whereas CuSO4 acts predominantly by local peritoneal irritation. A causal role for circulating OT in the acquisition of learned taste aversions was not found. These and other findings suggest that peripheral levels of OT may represent a quantifiable marker of visceral illness in rats and therefore might be useful in the interpretation of behavioral studies in which learned taste aversions are produced, provided that other stimuli of neurohypophyseal secretion are absent.
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PMID:Oxytocin and vasopressin secretion in response to stimuli producing learned taste aversions in rats. 301 74


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