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)

Plasma concentrations of the prostaglandin F metabolite 13,14-dihydro-15-keto-prostaglandin F (PGFM), the oxytocin-associated neurophysin (OT-N) and progesterone were monitored by radioimmunoassay (RIA) in five ewes sampled from the jugular vein at hourly intervals between 0700-1900 h from Days 12-16 of the estrous cycle. These hormones were also determined in plasma samples collected at similar times from five intact and five ovariectomized ewes given twice daily injections of medroxyprogesterone acetate (MPA) over Days 10 to 20 after the last observed estrus. In both the control and intact MPA-treated ewes, coincident surges of OT-N and PGFM were observed in jugular plasma during the time of luteal regression. No significant differences were noted in the number and amplitude of OT-N and number of PGFM peaks between the control and intact MPA-treated animals, although in the latter the amplitude of the PGFM peaks was significantly reduced (P less than 0.01). No marked surges in the plasma concentrations of PGFM or OT-N were observed in the ovariectomized ewes given exogenous MPA. This latter finding is consistent with previous proposals, suggesting that the ovaries are a major source of oxytocin in the ewe. In addition, the observation that exogenous progestogens in the intact ewes did not influence the number and peak height of the OT-N surges, indicates that a fall in progesterone levels during the normal cycle is not obligatory for oxytocin release although it may facilitate the release of uterine PGF2 alpha.
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PMID:Effect of exogenous progestogens on plasma concentrations of the oxytocin-associated neurophysin and 13,14-dihydro-15-keto-prostaglandin F in intact and ovariectomized ewes over the time of expected luteal regression. 622 41

1. A thiol proteinase from human pituitaries was purified approximately 400 fold and shown to have different chromatographic properties from that of calf brain. Among substrates cleaved were myelin basic protein, histones, beta-lipotropin, neurophysin, and Substance P. 2. The enzyme showed properties associated with a cathepsin-B like enzyme: dependence on -SH groups, pH optimum of 6.5, inhibition by leupeptin and a synthetic analog, Boc-D-Phe-Pro-arginal, and cleavage of dipeptidyl arylamides with basic residues adjacent to or penultimate to the chromatographic grouping. 3. Membranes present in the P2 fraction of rat brain contained three or more enkephalinases when submitted to DEAE-cellulose chromatography. Further purification on an IgG-Sepharose affinity column prepared with antibody to lung angiotensin converting enzyme indicated the presence of dipeptidyl carboxypeptidase(s) with properties distinct from those of ACE. In addition, the DEAE-cellulose fractions contained various aminopeptidase activities when tested with Leu-Gly-Gly, Leu-Nap, and Ala-Ala-Nap as substrates.
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PMID:Peptide processing in the central nervous system. 625 8

Subcellar localization of ionic Ca was investigated by the Pb-acetate cytochemical method in rat myometrium on the 21st day of pregnancy, following oxytocin and Bricanyl treatment. Following Oxytocin treatment the amount of ionic Ca increased in the muscle cells of the uterus and decreased in the plasma membrane and mitochondria as compared with the control. Tocolytics given in the last four days of pregnancy caused a decrease in the cytoplasmic concentration of ionic Ca and increased the Ca++ content of Ca++ pools (plasma membrane, mitochondrium). The change in the intracellular distribution of Ca++ may be involved in the mechanism of action of tocolytics and in the development of the relaxation of smooth muscle.
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PMID:Contributions to the mechanism of action of beta-adrenergic stimulants. 647 23

WRK-1, a cloned cell line derived from a rat mammary tumour, responds to physiological concentrations of vasopressin and pharmacological concentrations of oxytocin with increased incorporation of [14C]acetate into lipids and increased protein accumulation. The presence of pharmacological concentrations of insulin, which itself is active on the WRK-1 cells, further enhances the effects of the neurohypophysial hormones. Unlike the action of vasopressin on other responsive tissues, the stimulation of acetate incorporation by WRK-1 cells is not observed until 24 h after the addition of the hormone. The lipids synthesized in response to the hormones are predominantly polar lipids, rather than the triclyclycerold characteristic of the differentiated mammary gland. [1-Deaminocysteine, 8-D-arginine] vasopressin, a vasopressin analogue that lacks pressor activity, has no effect on WRK-1 cells.
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PMID:Neurohypophysial-hormone-responsive cell line derived from a dimethylbenzanthracene-induced rat mammary tumour. 677 66

Fertilized eggs from rabbits 1 or 2.5 days after insemination were transferred to the oviduct or uterine horn of recipients that had received a single subcutaneous injection of 20 or 30 mg of one of seven long-acting progestins. The rabbits were observed daily, and the number of implantation sites was determined 10 or 11 days after egg transfer. No implantation sites were recorded in the recipient does treated with progesterone or ZK-5623 (Schering AG, Berlin, West Germany), a nor-steroid compound. Thirty-nine percent and 51% of the transferred eggs implanted in the recipient does treated with ZK-5410 (Schering AG) and chloromadinone acetate (Eli Lilly & Company, Indianapolis, IN), respectively. However, most of the pregnant animals aborted 14 to 20 days after egg transfer. The pregnancy was either maintained to term or was prolonged beyond the normal gestation length in the does treated with other compounds, ZK-53915, ZK-9349 (Schering AG) or Depo-Provera (Upjohn Company, Kalamazoo, MI). The young delivered after a subcutaneous injection of 17 beta-estradiol and oxytocin were found normal and active.
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PMID:Maintenance of pregnancy in rabbits treated with long-lasting progestins. 685 82

The BE(2)-M17 and BE(2)-C human neuroblastoma cell lines have been shown to synthesize and secrete corticotropin-releasing factor (CRF) following retinoic acid treatment. It has been demonstrated that CRF secretion and intracellular synthesis increases in response to forskolin treatment. In this report, we have further characterized these cells in response to protein kinase C activators, dexamethasone, interleukin-1 alpha, as well as various neurotransmitters and peptides. Nanomolar concentrations of the phorbol ester--phorbol 12 myristate 13--acetate (TPA), increased intracellular CRF content in both cell lines while increasing secretion only in the BE(2)-M17 cell. Nanomolar concentrations of dexamethasone were not able to alter basal levels of secretion and content in either cell type. However, in the BE(2)-M17 cell but not the BE(2)-C cell, the same concentrations of dexamethasone added to 30 microM forskolin augmented levels of CRF secretion and content. Likewise, the same augmented response in CRF secretion and content was seen only in the BE(2)-M17 cell line when nanomolar concentrations of dexamethasone were added to 20 nM TPA. Furthermore, only in the BE(2)-M17 cell line were micromolar levels of the biogenic amine serotonin able to increase levels of CRF secretion and content. No effects on CRF in both cell lines were demonstrable with picomolar levels of interleukin-1 alpha as well as micromolar levels of acetylcholine, norepinephrine, arginine-vasopressin, oxytocin, and angiotensin-II. The potential usefulness of these cells as models of central nervous system or placental CRF-containing neurons is discussed.
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PMID:Regulation of corticotropin-releasing factor secretion and synthesis in the human neuroblastoma clones- BE(2)-M17 and BE(2)-C. 755 Feb 93

The regulation of prostaglandin E2 and prostaglandin F2 alpha in primary cultures of epithelial and stromal cells of bovine endometrium was investigated using two physiological agents, oxytocin and platelet-activating factor, and the protein kinase C activator, 4 beta-phorbol 12-myristate 13-acetate. At the basal level, epithelial cells produced more prostaglandin F2 alpha than did stromal cells (P < or = 0.0001) and stromal cells produced more prostaglandin E2 than did epithelial cells (P < or = 0.0001). In the presence of oxytocin, production of prostaglandin E2 and F2 alpha increased in a dose-dependent manner, only in epithelial cells. Stromal cells did not respond to oxytocin, suggesting that the oxytocin response is cell type specific, acting preferentially on the cell type in which prostaglandin F2 alpha is the major prostaglandin produced. Platelet-activating factor increased prostaglandin E2 and prostaglandin F2 alpha production in epithelial cells at 1 and 10 pmol l-1 (PGE2: 10 pmol l-1, P < or = 0.01; PGF2 alpha: 1 pmol l-1, P < or = 0.02). Stromal cells also responded to platelet-activating factor, but only at high concentrations (PGE2: 0.1 mumol l-1, P < or = 0.001; PGF2 alpha: 0.1 mumol l-1, P < or = 0.0001). These results further demonstrate the differences in epithelial and stromal cells; epithelial cells are more sensitive to platelet-activating factor than are stromal cells. Phorbol 12-myristate 13-acetate increased prostaglandin production in a dose-dependent manner in both epithelial and stromal cells, indicating that protein kinase C activation can increase prostaglandin production in these cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cell type specificity and protein kinase C dependency on the stimulation of prostaglandin E2 and prostaglandin F2 alpha production by oxytocin and platelet-activating factor in bovine endometrial cells. 761 96

The control of temporal changes in oxytocin receptor concentrations and oxytocin-induced 13,14-dihydro-15-keto PGF2 alpha (PGFM) release was examined in ewes. One week after ovariectomy, 36 ewes were administered fluorogesterone acetate for 10 days followed by oestradiol (3 x 16 micrograms day-1) for 2 days (pretreatment cycle). Day 0 was designated as the time of the final 'oestrous' oestradiol injection. Ewes were then treated for up to 12 days with progesterone (24 mg day-1 maximum) with or without oestradiol (both hormones administered in 1 ml of corn oil i.m. at 8 h intervals) in a pattern known to simulate natural plasma profiles of the oestrous cycle. The three treatments were zero oestradiol, low oestradiol (12 micrograms day-1 maximum), and high oestradiol (36 micrograms day-1 maximum). Subgroups of four ewes from each treatment group were given 1 microgram of oxytocin (i.v.) on day 10, 11 or 12 of the simulated cycle, and endometrial oxytocin receptor concentrations were determined in samples collected within 3 h of oxytocin administration. On day 10 only one ewe in each group exhibited a PGFM response to oxytocin, and the mean response was unaffected by the concentration of oestradiol administered. On days 11 and 12 there was a significant effect of oestradiol concentration (P < 0.05) on the pattern of PGFM release in response to oxytocin, the high oestradiol concentration causing a rapid increase in the concentration of PGFM following oxytocin administration. On day 12 the oestradiol concentration was positively correlated with the PGFM mean response (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oestradiol concentration and the development of the uterine oxytocin receptor and oxytocin-induced PGF2 alpha release in ewes. 802 65

High concentrations of PGF2 alpha and PGE2 are produced by the uterus during the early postpartum period in cows and may play an important role in both placental separation and uterine involution. In the present study, we have examined the hormonal and intracellular control mechanisms involved in PGF2 alpha and PGE2 secretion by caruncular and allantochorionic tissue in vitro. Tissue explants, obtained about 6 hr postpartum from cows that delivered normally (NFM, n = 10) or cows with retained fetal membranes (RFM, n = 4), were incubated for 6 hr and PGF2 alpha and PGE2 concentrations in the medium were determined by radioimmunoassay. Addition of oxytocin (100 microU/ml), platelet activating factor (PAF, 100 ng/ml) and epidermal growth factor (EGF, 100 ng/ml) had no effect on secretion of PGF2 alpha from the caruncle, but oxytocin and PAF did stimulate PGE2. There was no difference between groups of cows. All three substances stimulated PGF2 alpha from the allantochorion of NFM, but not RFM, cows and stimulated PGE2 secretion from the allantochorion of both groups of cows. Incubation of the tissues with cholera toxin (100 ng/ml), dibutyryl cyclic adenosine 3',5'-monophosphate (dibutyryl cAMP, 1 mM), calcium ionophore A23187 (5 microM) or phorbol ester 12-myristate-13 acetate (PMA, 100 nM) showed that PGF2 alpha secretion is essentially via the calcium-protein kinase C effector pathway. However, calcium-protein kinase C and cAMP second messenger systems appear to be involved in the secretion of PGE2. Prostaglandin secretion was sensitive to cycloheximide in both caruncular and allantochorionic tissues, suggesting that protein synthesis may be involved. In conclusion, these data show that in vitro PGF2 alpha secretion can be modulated by the agonists used only in allantochorion and is essentially via the calcium-protein kinase C effector pathway. PGE2 secretion can be modified in both caruncular and allantochorion tissues and involves both inositol triphosphate-diacylglycerol and cAMP second messenger systems.
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PMID:Control of in vitro prostaglandin F2 alpha and E2 synthesis by caruncular and allantochorionic tissues from cows that calved normally and those with retained fetal membranes. 804 99

The spontaneous contractions of the rabbit uterine horns and the human myometrial strips were stimulated by oxytocin and buserelin acetate in isolated preparations. Spironolactone application to these models produced inhibitory effects on the contractions. It is concluded that spironolactone has inhibitory effect on the rabbit uterine horn and the human myometrial strip contractions.
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PMID:Inhibitory effect of spironolactone on the contractions of the rabbit uterine horn and the human myometrial strip. 806 67


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