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)

Studies were made to determine the effect of various contraction-inhibitors against spontaneous uterine contraction in rats during late pregnancy. 1) The duration and rate of inhibitory activity differed from inhibitor to inhibitor, showing dose-response relationship. As a result of this investigation of the changes in the intensity and frequency for 17 inhibitors, Ca-blocker, beta 2-stimulants and dibutyryl c-AMP had the strongest effects, PG-antagonist, and the anti-inflammatory drugs such as aminophylline were much weaker in their inhibitory activity. 2) When the progress of uterine inhibition was investigated on the basis of quantitative changes of PG and c-AMP in bath medium, it was found that both PGE1 and PGF2 alpha were significantly reduced after administration of terbutaline and indomethacin, c-AMP decreased significantly after administration of PGE1 analogue, oxytocin and PGF2 alpha. The c-AMP levels increased significantly after administration of terbutaline and verapamil. These were no significant changes in c-AMP levels when indomethacin and aminophylline were used. During the administration of the uterine inhibitors, c-AMP increased significantly both in vivo and in vitro. Therefore, c-AMP may be regarded as an important parameter indicating the degree of inhibition of contraction.
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PMID:The comparative actions of uterine inhibiting drugs in the pregnant rat. 611 60

Clinical studies throughout the world will probably result in the use of prostaglandins (PGs) in the near future for treatment of some cardiovascular, gastrointestinal, and respiratory diseases in addition to their present use in gynecology and obstetrics. The discovery in 1971 that acetylsalicylic acid and a series of other nonsteroidal anti-inflammatory drugs inhibit the biosynthesis of PGs provided an explanation for the analgetic, antipyretic, and anti-inflammatory activity of these drugs and formed a rational base for their use in a variety of pathological situations believed to involve PGs. The most important indications for the use of PGs in human reproduction include induction of labor; cervical priming; termination of pregnancy in the 2nd or 1st trimester; management of fetal death, missed abortion, intrauterine death near term, hydatidiform mole, and anencephaly; and postpartum hypotonus. 1 of the main contributions of PGs in obstetrics is their ability to stimulate the uterus throughout pregnancy and their suitability in cases in which the uterus is not receptive to oxytocin. Work is underway to develop more satisfactory routes of administration, perhaps vaginally, to achieve more satisfactory control of side effects, and to increase the duration of action through development and substitution of synthetic androgens. PG biosynthesis inhibitors have been used successfully in treatment of premature labor in some cases. PGs of the E series have been used for temporary treatment of cardiac malfunction such as transposition of the main arteries or pulmonary atresia, the vasodilating PGs such as PGI2 or PGE1 have been used in peripheral vascular disease such as arteriosclerosis obliterans and Raynaud's disease, and are currently under investigation in the treatment of pulmonary hypertension, spontaneous angina, and toxemia. Prostacyclin has recently become available in Great Britain as an antiaggregating agent for use during charcoal hemoperfusion, hemodialysis, and extracorporeal circulation in open heart surgery. The antisecretory activity of PGs, partially mediated through a stimulation of mucus secretion, has led to their use in treatment of stomach ulcers. Clinical application of PGs in respiratory problems has not progressed far, but recently synthesized analogues could become useful in treatment of some asthmatic disorders.
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PMID:Clinical use of prostaglandins in perspective. 686 38

The present experiments were performed to investigate whether the responses of the myoepithelium to several drugs would be of a parallel nature with those of the vascular smooth muscle in the lactating mammary gland of goats. The drugs were injected into the mammary artery. Kallikrein, bradykinin, oxytocin, and acetylcholine caused marked milk-ejection with vasodilation in a dose-dependent manner. Marked milk-ejections with high doses of oxytocin were observed despite of accompanying vasoconstriction. The relative order of their potency in milk-ejection activity was kallikrein greater than bradykinin greater than oxytocin greater than acetylcholine: 1 greater than 1/100 greater than 3/1000 greater than 5/1000000. As for the vasodilator activity, the relative potency of the drugs was in the same order: 1 greater than 1/10 greater than 1/1000 greater than 1/10000. Catecholamines, histamine, serotonin, angiotensin-II, vasopressin and high doses of prostaglandin E2 caused dose-dependent vasoconstriction. Isoprenaline, pilocarpine, adenosine, PGI2 and low doses of PGE2 caused dose-dependent vasodilation. But these drugs did not affect milk-ejection. PGE1 decreased milk-ejection and was accompanied by vasodilation. From these experiments it is suggested that the relative order of the potency of secretagogues in milk-ejection activity and in vasodilator activity is nearly equal. It is also suggested that some drugs are different in their effects on the myoepithelium and on the vascular smooth muscle of the lactating mammary gland.
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PMID:Pharmacological effects of several drugs on the myoepithelium and the vascular smooth muscle of the lactating mammary gland in goats. 692 Feb 63

In order to clarify the onset mechanism of labor, we studied the prostaglandin production in human placenta tissues of different stage using a superfusion technique. 1) The placenta obtained at Cesarean section before the onset of labor (A): (1) In the control, the production of prostaglandins was not distinctly changed. (2) Administration of arachidonic acid increased gradually the production of PGs. PGs production showed the maximum values at 50-60 minutes fraction of the superfusion. Throughout the experiment, PG production became vigorously active. (3) Administration of oxytocin increased the production of PGs, too, in particular PGE2 and PGF2 alpha. 2) The placenta obtained at Cesarean section during delivery (B): (1) In the control, the production of PGs was not distinctly changed. (2) Administration of arachidonic acid increased the production of PGE2 and PGF2 alpha, but the production of PGs was lower as compared with (A). PGE1 did not change. (3) Oxytocin had no effect on the production of PGE1 and PGE2, but the production of PGF2 alpha showed the maximum values at 50-60 minutes fraction. 3) The delivered placenta (C): (1) In the control, the production of PGs was not distinctly changed. (2) Administration of arachidonic acid increased the production of PGs. (3) Oxytocin had no effect on the production of PGs. On the basis of these data, it may be appropriate to conclude as follows: The enzyme which has a high ability to produce PGs exists in the placenta before the onset of labor. But the enzyme keeps the resting condition by the some inhibiting factor of PG production. During delivery, the PG production by the placenta fell. This result means that the strong ability of the production of PGs by the placenta at this stage is not necessary. After the delivery, the production of PGs by the delivered placenta is unnecessary. It is substantiated Kato's theory which PGE is primarily involved in the onset of labor that the production ability of PGE was recognized only in the placenta of before the onset of labor. It is interesting that administration of oxytocin increased the production of PGF2 alpha and they are similar for the contraction-substance of uterus.
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PMID:[Prostaglandin Production by the human placenta using a superfusion technique (author's transl)]. 694 92

Abortifacient effects of 16,16-dimethyl-trans delta 2-PGE1 methyl ester (ONO-802) were studied clinically. The uterine contractile effect of the agent was compared with those of PGF2 alpha and oxytocin (OXY) in the unanesthetized rabbit. 1. Intermittent intravaginal administration of ONO-802 was applied to 32 cases of legal abortion, 15 of missed abortion and 17 of hydatid mole. Eighty eight, 100 and 81 per cent of these patients resulted in abortion, respectively, with fewer side effects than those of natural PGs. 2. In the five groups of non- or pseudo-pregnant rabbits and those in their 7-9, 14-16 and 19-28 days in pregnancy, uterine contractile effects of these agents were assessed by both the contractile patterns and area of contractile curves of initial 5 minutes. The results are as follows: 1) In the non-pregnant rabbits, all of these agents revealed marked uterine contractile effect. 2) ONO-802 induced uterine contraction characterized by its wedge-shaped curves continued considerably longer than that induced by others. 3) ONO-802 revealed much stronger effect on uterine contraction in 7-9 day-of-pregnant rabbits. 4) Fourteen-16-day-of-pregnant rabbits were least influenced by the three agents as regards their uterine contraction in accordance with the highest progesterone levels in their sera among the three groups of pregnant rabbits.
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PMID:[A study on the uterine contractile effect of 16, 16-dimethyl-trans-delta 2-PGE1 methyl ester (ONO-802) (author's transl)]. 695 Sep 90

To clarify the mechanism of labor onset, the effect of exogenous oxytocin (OT) on tissue prostaglandin (PG) formation was studied in vivo. Changes of PG concentrations of the uterine venous plasma, myometrium, fetal and maternal cotyledons of placenta, and parietal decidua of late pregnant rabbits were evaluated between just before and 10 minutes after administration of 10 IU of OT. PGE1, PGE2, and PGF2 alpha were extracted from each tissue by Inagawa's method and measured by radioimmunoassay. Concentrations of PGE1 (344-1,280 ng/g wet weight) and PGE2 (656-3,000 ng/g wet weight) of the fetal cotyledon were 2-30 times higher than those of other tissues regardless of OT administration. Differences in PG concentrations between before and after OT administration were compared. The results were: 1) Changes of PGs in the plasma, fetal cotyledon, and parietal decidua showed no definite tendency after OT administration. 2) In the myometrium, all measured PG decreased after OT administration, suggesting that tissue PGs are not concerned with myometrial contraction when induced by exogenous OT. 3) In the maternal cotyledon of the placenta, PGs increased after OT administration, suggesting that the maternal cotyledon is the only site having close relationship between OT administration and PGs formation in vivo.
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PMID:[Effect of oxytocin administration on prostaglandin concentrations in uterine and placental tissues of pregnant rabbit (author's transl)]. 723 43

In order to investigate the role of oxytocin (OT) and prostaglandins (PGs) in the mechanism of labor onset, changes of OT and PGs levels in human plasma were evaluated before labor, soon after the labor onset, and at the time of established labor in the following three groups. Group 1 consisted of 6 cases with spontaneous labor, group 2, of 6 cases with induced labor with PGF2 alpha drip infusion, and group 3, of 5 cases with induced with PGE2 vaginal suppository. OT concentrations were measured by RIA, PGE1, PGE2, and PGF2 alpha were extracted and determined by Inagawa's method. Levels of OT in group 1 were divided into two subgroups: subgroup 1 with high OT levels (24.0-116.2 microunits/ml) and subgroup 2 with low OT levels (below 7.2 microunits/ml) throughout labor. Changes of PGs level in subgroup 1 showed no definite tendency during labor, suggesting that OT appears to play the leading role in spontaneous labor. Those in subgroup 2 showed a particular behavioral pattern during labor, suggesting an important role played by PGs for the onset of labor following rupture of the membranes. The results of groups 2 and 3 are fully discussed in terms of labor process.
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PMID:[Alterations of oxytocin and prostaglandin E1, E2, F2 alpha levels in human plasma during labor (author's transl)]. 723 49

In rats on day 20 of pregnancy, ONO-802 exerted a uterine contractile effect when 0.2 microgram/kg was given i.v. and also with an intrauterine administration of 0.5 ng, s.c. administration of 1 microgram/kg and vaginal administration of 10 microgram/kg. The contractile activity of ONO-802 was 100-1000 times more potent than that of PGE2 alpha and was long-acting. Intravenous PGE1 or PGE2 induced a transient contraction followed by inhibition of spontaneous uterine motility in nonpregnant rats and in those with an early pregnancy. In nonpregnant hamsters, a relaxation was seen. ONO-802, similar to PGF2 alpha, showed a contractile effect regardless of states of nonpregnancy and pregnancy, both rats and hamsters. IN rats, a contractile threshold dose of ONO-802 was similar from day 15 to day 21 of pregnancy. Oxytocin produced an acute decrease in this threshold dose on phentolamine or methysergide, but was inhibited by papaverine, dibutyryl cAMP, salbutamol and verapamil. These results suggest that uterine contraction induced by ONO-802 differs from the contractions induced by PGE1, PGE2, and oxytocin, that ONO-802 does not induce endogenous PGs, and that the effect of ONO-802 is not mediated by the autonomic nervous system.
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PMID:[Effects of 16,16-dimethyl-trans-delta 2-PGE1 methyl ester (ONO-802) on uterine motility (author's transl)]. 732 52

Doses of the drugs which produce uterine contraction were given intravenously to various species of animals. Placental and ovarian circulations were measured by the thermocouple method and/or microangiography. Uterine arterial blood flow (UABF) was measured by the electromagnetic flowmeter. Both placental blood flow (PBF) and UABF decreased with the administration of ONO-802, PGE1 or PGF2 alpha to to rabbits and dogs. Oxytocin and noradrenaline also decreased PBF in rabbits. ONO-802 or PGE1 lowered arterial blood pressure (BP) in rats, rabbits and dogs. PGE2 alpha elevated BP in rats and dogs and lowered it in rabbits. Oxytocin produced no changes in PB while noradrenaline elevated BP in rabbits. Ovarian blood flow in pregnant rabbits was reduced by ONO-802, PGE1 or PGF2 alpha. Little influence was seen with oxytocin. Regarding the luteal microvasculature in pregnant rats, ONO-802, PGF2 alpha and noradrenaline exhibited vasoconstricting effects. PGF2 alpha induced abortion and decreased plasma progesterone levels. These results suggest that the inhibitory effects of ONO-802 on the uterine and placental circulation are strongly influenced by the uterine contractile effect and that the inhibitory effect on the ovarian circulation in rats is one of pharmacological effects not concerned with the abortifacient or luteolytic effect.
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PMID:[Effects of 16,16-Dimethyl-trans-delta 2-PGE1 methyl ester (ONO-802) on uterine, placental and ovarian circulation (author's transl)]. 732 53

The efficacy of misoprostol (a PGE1 analog) for induction of labor at term was compared with oxytocin by means of an open and randomized study in 153 pregnant women. A vaginal tablet containing 50 mcg of misoprostol was placed intravaginally in 78 women, the remaining 75 patients received i.v. oxytocin (2-32 mU/min). Bishop's score at the entry of the trial was similar in both groups. Delivery within 24 hours was achieved in 85.7% of the patients induced with misoprostol and in 64% of the patients infused with oxytocin (p < 0.05). Mean induction to delivery interval was significantly shorter in the misoprostol group (552 +/- 211 min; mean =SD) in comparison with that of the oxytocin group (745 +/- 292 min; mean +/- SD) (p < 0.05). The probability of still being pregnant at 24 hours (Life table analysis) was 14% (misoprostol group) and 26% (oxitocyn group). The difference was also statistically significant (p < 0.01). No undesirable side effects were observed in any of the patients, however, polisystoly (> 5 contractions in 10 min) was more frequently observed in the patients induced with misoprostol (24.6% vs 13.3%; p = NS). Cesarean section rate was higher in the oxytocin-induced patients (25.3%) than in the misoprostol-induced women (3.8%) (p < 0.05). The main cause of cesarean section was failure to progress in labor in both groups of patients. Neonatal outcome was good in both groups and there were no differences with respect to birthweight or to Apgar scores.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Misoprostol--a PGE1 analog for induction of labor at term: comparative and randomized study with oxytocin]. 765 11


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