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)

Oestrous cycles of goats were synchronized hormonally. Immunoreactive oxytocin was undetectable (less than 0.1 ng/mg protein) in media from granulosa cells isolated before the LH surge for small (1-2 mm), medium (3-5 mm) and large (greater than 5 mm diameter) follicles when cultured for 24 h without or with added hormones. Granulosa cells from large and medium, but not small, follicles isolated 6-12 h after spontaneous preovulatory LH surges secreted high concentrations of oxytocin (4-12 ng/mg protein). Addition of PGE-2 (1 microgram/ml) caused a further significant (P less than 0.05) increase in oxytocin secretion by cultured granulosa cells, whereas PGF-2 alpha, FSH and LH were ineffective when added to culture media. Ovarian venous blood and granulosa cells were collected at 0, 6, 12 or 18 h after GnRH injection in hormonally synchronized goats. Peripheral serum LH values were increased significantly in all but 2 of 22 goats within 2 h of GnRH injection. At the earliest sampling time after GnRH (6 h), ovarian venous levels of oxytocin were increased significantly from basal levels of 0.4 pg/ml to 2.4 pg/ml. Oxytocin concentrations in follicular fluid increased from a basal value of 67 pg/ml to 155 pg/ml by 6 h and to 372 pg/ml by 18 h after GnRH injection. Oxytocin secretion by cultured granulosa cells was not increased significantly by 6 h (0.1 ng/mg protein) but rose to 1.4 and 3.5 ng/mg protein at 12 and 18 h, respectively. Approximately parallel increases occurred in progesterone in ovarian venous blood and granulosa cell culture media over the same time period. (ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Preovulatory biosynthesis and granulosa cell secretion of immunoreactive oxytocin by goat ovaries. 251 89

Sheep conceptuses secrete a protein, ovine trophoblast protein-1 (oTP-1), between days 10 and 21 of gestation, that is responsible for establishment of pregnancy. oTP-1 inhibits uterine production of episodic release of prostaglandin (PG) F2 alpha (PGF) necessary for luteolysis and produced in response to oestradiol and oxytocin. oTP-1 does not compete with oxytocin for binding to its receptors or interfere with oxytocin stimulation of the inositol phospholipid second messenger system after oxytocin receptors are formed. However, oTP-1 may affect synthesis of oxytocin, oestrogen and/or progesterone receptors to alter the ability of the uterus to produce episodic pulses of PGF in response to episodic pulses of oxytocin. Porcine conceptuses secrete oestrogens between days 10 and 15 of pregnancy that are essential for establishment of pregnancy. Oestrogens, directly or indirectly, alter secretion of PGF from an endocrine direction (toward the uterine vasculature) to an exocrine direction (toward the uterine lumen). PGF sequestered in the uterine lumen is unavailable to exert a luteolytic effect on the corpus luteum (CL). Pig conceptus secretory proteins stimulate uterine production of PGF and PGE, but do not appear to be responsible for inhibition of luteolysis. Conceptus secretory proteins of sheep and pigs include proteins that have antiviral activity and are considered interferons. In sheep, oTP-1 has antiluteolytic, immunosuppressive, antiviral and possibly antiproliferative properties. The specific pig conceptus secretory protein(s) possessing antiviral activity has not been established. Unlike oTP-1, however, pig interferon-like protein(s) does not appear to possess antiluteolytic activity.
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PMID:Establishment of pregnancy in sheep and pigs. 268 7

Sheep conceptuses secrete a protein, oTP-1, between Days 10 and 21 of gestation which is responsible for establishment of pregnancy. oTP-1 inhibits uterine production of luteolytic amounts of PGF-2 alpha (PGF) produced in response to oestradiol and oxytocin. oTP-1 does not compete with oxytocin for binding to oxytocin receptors, but may interfere with oxytocin stimulation of the inositol phospholipid system. Pig conceptuses secrete oestrogens between Days 10 and 15 of pregnancy which are essential for establishment of pregnancy. Oestrogens, directly or indirectly, alter secretion of PGF from an endocrine direction (towards uterine vasculature) to an exocrine direction (towards the uterine lumen). PGF sequestered in the uterine lumen is unavailable to exert a luteolytic effect on the CL. Pig conceptus secretory proteins stimulate uterine production of PGF and PGE. Conceptus secretory proteins of sheep and pigs include proteins which have antiviral activity and may be considered interferons. In sheep, oTP-1 has both antiluteolytic and antiviral properties. The specific pig conceptus secretory proteins(s) possessing antiviral activity has not been established. Unlike oTP-1, however, it does not appear to possess antiluteolytic activity.
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PMID:Comparative aspects of maternal recognition of pregnancy between sheep and pigs. 281 Feb 36

Bovine conceptuses exert an antiluteolytic (anti-PGF-2 alpha) effect on the uterus by decreasing the secretion of PGF that results in maintenance of the CL. Basal and oxytocin-stimulated secretion rates of PGF from perifused endometrium are lower at Day 17 of pregnancy than at Day 17 of the oestrous cycle, probably because of increased amounts of an intracellular, endometrial PG-synthesis inhibitor which is present in the 100,000 g cytosolic supernatant, is proteinaceous, and acts in a noncompetitive manner with respect to arachidonic acid. The antiluteolytic signal in bovine conceptus secretory proteins (bCSP) is bovine trophoblast protein-1 (bTP-1), a group of 7 isomers of N-linked glycoproteins in two size classes (22,000 high-mannose and 24,000 complex types) that are related immunologically to ovine trophoblast protein-1 (oTP-1). Incubation of endometrial explants of Day-17 cyclic cows with bCSP and bTP-1 induced PG-synthesis inhibitor activity and reduced PGF secretion. Intrauterine infusion of bTP-1 from Days 15.5 to 21 extended the interoestrous interval from 19.5 to 26.0 days. Intrauterine infusion of interferon-alpha I 1 through the cervix from Day 15.5 to 21 extended the interoestrous interval from 22.8 to 26.8 days. Platelet-activating factor (PAF) and interferon-alpha I 1 alter PG secretion of endometrial explants (PAF decreases PGF and increases PGE-2; interferon-alpha I 1 does not alter PGF and increases PGE-2 secretion) but neither induces activity of the endometrial PG-synthesis inhibitor. In conclusion, bovine conceptuses exert a paracrine effect through the secretion of bTP-1 to induce an endometrial intracellular inhibitor of PGF synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antiluteolytic effects of bovine trophoblast protein-1. 281 Feb 37

We have investigated the effects of exogenous oxytocin and prostaglandin F2 alpha (PGF2 alpha) on the concentrations of prostaglandins E and F (PGE and PGF) in the utero-placental tissues in late pregnant rabbit. The subjects were 5 rabbits each on days 26, 27 and 30 of pregnancy. After one side of the uterine horn was excised as the control, 3,000 micrograms of PGF2 alpha, 10 microU of oxytocin or 1 ml of saline was administered to 2,2 and 1 rabbits as an iv bolus dose. After 10 minutes, the remaining side of the uterine horn was excised. The myometrium, fetal and maternal cotyledon, decidua and amnion were separated. The concentrations of PGE and PGE in each tissue were measured by radioimmunoassay after extraction. The highest concentration of PGE was observed in the fetal cotyledon and that of PGF in the decidua. The amniotic PGE concentration significantly decreased after the administration of both oxytocin and PGF2 alpha. The myometrial PGF concentration increased significantly after the administration of PGF2 alpha, and the degree of the increase in PGF became greater as pregnancy advanced. However, the myometrial PGF concentration did not increase after the administration of oxytocin.
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PMID:Changes in the concentrations of prostaglandins E and F in the utero-placental tissues of late pregnant rabbit after the administration of oxytocin or prostaglandin F2 alpha. 316 8

To observe the changes in endogenous oxytocics during spontaneous and induced labor, the plasma concentrations of oxytocin, prostaglandin E1 (PGE1) and 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were measured during labor in 9 cases of spontaneous labor (group 1), 10 of PGE2-induced labor (group 2), and 7 of PGF2 alpha-induced labor (group 3). Unextracted samples were used for radioimmunoassay of oxytocin. PGE and PGF were extracted and separated for radioimmunoassays of PGE1 and PGFM. Although oxytocin levels in groups 1 and 3 did not change during labor or slightly increased toward delivery, those in group 2 decreased as labor progressed. The mean oxytocin in group 2 was significantly lower at the times of established labor (15.3 +/- 3.2 microU/ml, mean +/- SE) and crowing of the fetal head (10.8 +/- 2.0 microU/ml) than before labor (52.7 +/- 14.8 microU/ml). Plasma PGE1 levels in groups 1 and 3 were low and did not change during labor. Plasma PGFM levels in groups 1 and 2 gradually rose toward delivery. These results suggest that exogenous PGE2 suppresses oxytocin secretion during labor and stimulates endogenous PGF2 alpha production, that endogenous PGE1 may not play an important role in the progress of spontaneous and PGF2 alpha-induced labor, and that endogenous PGF2 alpha may participate in the promotion of all kinds of labor.
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PMID:Changes in plasma oxytocin, prostaglandin E1, and 13,14-dihydro-15-keto-prostaglandin F2 alpha during labor induced by prostaglandin E2 or F2 alpha and spontaneous labor. 347 3

The prostaglandins(PGs), unlike oxytocin, are powerful stimulants of uterine contractility in early, middle, and late pregnancy. This characteristic has led to the use of PGs as agents for termination of mid-trimester pregnancy. For this purpose, local routes of administration--extraamniotic or intraamniotic--have proven superior to intravenous administration. PGs have proven particularly useful in inducing labor in cases of fetal death in utero, fetal anomaly such as anencephaly, or in complications of pregnancy. PGE was administered extraamniotically to induce labor in cases of fetal death, anencephaly, and hydatidiform mole. The method was similar to that employed for 2nd trimester abortion, i.e., introduction of a Foley catheter through the cervix and retention of the catheter with a balloon. A similar method, minus the balloon, was used for 40 cases at or near term. These studies led to the conclusion that the Foley catheter might be particularly useful in inductions under unfavorable cervical conditions, i.e., cases where the cervix has not dilatated at all or hardly at all. Infusion of PGE2 in 7 cases with very low Bishop cervical scores proved successful in all cases. The exact infusion procedure is explained. The use of a Foley catheter with a balloon is known to have a ripening effect on the cervix. Combination with local PG administration seems to be particularly effective in causing cervical dilatation.
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PMID:Letter: Prostaglandins and the unfavourable cervix. 412 62

This is a review from the literature dealing with the physiology of prostaglandins (PGs). PGs E and F are biosynthesized from straight chain C-20 fatty acids, arachidonic acid being the precursor of 2 of the series and dihomo-linolenic acid the precursor of the other series. Availability of certain cofactors during synthesis probably determines which PG is formed. The amounts of PGs in the tissues are very low, indicating that they are biosynthesized immediately before hormone-stimulated release. PGs seem to be metabolized by all body tissues. PGE and PGF cannot act as circulating hormones since they are 95-99% deactivated by 1 passage of the blood through the lungs. The following roles of PGs in the reproductive process are discussed: 1) present in semen, they may aid in fertilization; 2) they may function as mediators between luteinizing hormone and cyclic AMP during ovulation; 3) they may facilitate release of anterior pituitary hormones; 4) they act to stimulate progesterone secretion; 5) they act in some species as the uterine luteolytic hormone; and 6) they sensitize the uterus to oxytocin during delivery. Since every body tissue appears to be able to synthesize PGs, they also have other physiological functions.
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PMID:The physiology of prostaglandins. 435 87

This letter comments on a previously published article (August 17, p. 428) relating to the use of prostaglandins for midtrimester abortion. It is estimated that prostaglandin PGF-2-alpha given by the i ntrauterine route has been used in over 5000 patients; 13 cases of cervi cal rupture have been reported. Most ruptrues have occurred in primigravidae. All but 1 of them (who received PGE-2) were given PGF-2-alpha intraamniotically. Periods of gestation have been 15-22 weeks. Large doses of prostaglandins have been used and often supplemented by other oxytocics such as urea or oxytocin. No reported cervical ruptures have followed use of PGE-2 alone, possibly because of its relaxant effect on the cervix. Previous gradual dilatation of the cervix with laminaria tents or with some synthetic prostaglandin analogue is being studied. In first trimester pregnancies prostaglandin analogues given as a single extraamniotic dose 12 or more hours prior to termination has been shown to effect gradual dilatation of the cervix. Of 88 such cases, only 3 required mechanical dilatation of the cervix. It is felt that prostaglandins offer an attractive alternative to hysterotomy or hypertonic saline for terminating second trimester pregnancies when overstimulation of the uterus by large doses is avoided.
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PMID:Letter: Mid-trimester termination. 441 98

This paper attempts to assess the present status of the use of prostaglandins (PGs) in induction of labor. According to the published literature over 1000 patients have been treated with intravenous administration of PGF2alpha, a method which seems to be at least as effective as oxytocin infusion. Some authors suggest that this mode of action may be more effective in patients with lower Bishop scores at start of infusion. Intravenous infusion of PGE2alpha has been found to be 10 times more potent than PGF2alpha, regardless of mode of administration; success rates and amount of side effects are similar. Oral administration of PGE2alpha has shown to be as effective as oxytocin in 786 elective inductions of labor; the oral way of administration is more effective in the latent and early active phase of labor. 15 methyl PGE, a chemically modified PG, is as effective as its parent compound, has the same side effects, can be used in smaller amounts, but does not have any major advantages over the natural compound. In general it takes less than 1/10 the dose of PG to initiate labor than it takes to induce abortion, and the side effects are reduced about the same degree; since PGs may cause hypertonus care should be taken in monitoring the fetal condition and in controlling the rate of PG administration. Considerable work is needed before the full value of PGs in induction of labor can be assessed.
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PMID:The use of prostaglandins for the induction of labor. 469 70


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