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)

Oxytocin (OT) was synthesized employing the solid phase method. Resins made of copolymers of polystyrene-1%-crosslinked with divinylbenzene gave better yields (73-95%) of Z-Cys(Bzl)-Tyr(Bzl)-Ile-Gln-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 (I) than 2%-crosslinked resins (10--56%). Reduction of I with Na-liq.NH3 and oxidation with I2-MeOH at -40 degrees minimized dimer and polymer formation, and resulted in good yields (49--54%) of OT. The large volumes of MeOH required when several grams of I are reduced and then oxidized were rapidly evaporated in vacuo, and the residue was desalted by dissolving the peptide in a small volume of glacial acetic acid and filtering to remove the salt. OT was purified by adsorption chromatography on a silica gel column with combinations of MeOH-CHCl3 of graded polarity. Oxytocin elutes with 33% MeOH-CHCl3. After two purification steps by adsorption chromatography, the resulting OT was found to be homogeneous. The hormone was characterized chemically and found to be active biologically.
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PMID:Synthesis of oxytocin using iodine for oxidative cyclization and silica gel adsorption chromatography for purification. 42 90

Sections of the hypothalamus, median eminence and pituitary from fetal and neonatal rats were examined with the immunoperoxidase staining technique and light microscopy. Purified antisera raised against vasopressin and oxytocin, and antisera cross-reactive with rat neurophysin were used to localize these antigens in the hypothalamo-neurohypophysial system (HNS). Neurophysin was detected throughout the HNS of the 18-day fetal rat. Vasopressin was present in the hypothalamus and pituitary of the 19-day fetus, and in the median eminence of the 4-day neonate. Oxytocin was not detected in the pituitary until 1--2 days after birth, in the hypothalamus after 4 days, and in the median eminence after 8 days. During the first days after birth the supraoptic nucleus was more mature than the paraventricular nucleus. The HNS did not approach maturity until at least 7 days after birth. The relative maturity of the supraoptic nucleus compared with the paraventricular nucleus, and the detection of vasopressin before oxytocin are evidence for the one-neuron-one-hormone theory. The data do not exclude the possibility that the fetal hypothalamo-neurohypophysial system, and perhaps the fetal hormone, vasotocin, affect the initiation and course of parturition.
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PMID:Maturation of the hypothalamo-neurohypophysial system. I. Localization of neurophysin, oxytocin and vasopressin in the hypothalamus and neural lobe of the developing rat brain. 43 49

The use of agarose-bound neurophysin for the extraction of oxytocin from biological fluids is described. Oxytocin can be extracted from plasma, urine and cerebrospinal fluid with a high rate of recovery and samples varying widely in volume and oxytocin concentration can be tested by the method. Columns can be used to extract and concentrate dilute samples, or to help identify small amounts of neurohypophysial hormones by affinity chromatography. The oxytocin can be eluted from the column directly into the buffer used for subsequent bioassay. The composition of the final extract is constant and independent of the composition of the sample. The specificity of the binding is high. It is suggested that the method has many advantages over others in current use.
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PMID:Extraction of small amounts of oxytocin from biological fluids by means of agarose-bound neurophysin. 43 95

A sc injection of 2 micrograms arginine vasotocin (AVT) administered every 2 h for a 25-h period starting 1 h after castration of adult male rats caused a 43% reduction (P less than 0.05) in plasma levels of LH compared to diluent-treated castrated controls. In Exp 2, a sc injection of 5 micrograms AVT or diluent was administered to intact or acutely castrated male rats every 3 h for 48 h. After AVT administration, both plasma LH (P less than 0.001) and FSH (P less than 0.05) were significantly reduced, with a concomitant increase in pituitary levels of these gonadotropins. Using the same injection regimen in Exp 3, 250 micrograms melatonin had no effect on plasma or pituitary levels of LH in castrated male rats. In the fourth experiment, neither 1 IU arginine vasopressin nor 1 IU oxytocin had an effect on plasma or pituitary levels of LH, whereas 1 IU of AVT significantly lowered plasma levels of LH (P less than 0.05) and prevented the fall in the pituitary level of this gonadotropin (P less than 0.01) when compared to diluent-treated castrated control rats. Oxytocin (1 IU) significantly inhibited (P less than 0.01) plasma levels of FSH and raised plasma levels of PRL (P less than 0.01) in castrated male rats. No effect on plasma titers of PRL were observed after treatment of castrated rats with AVT in Exp 2 or 4. It is concluded that in acutely castrated male rats, AVT could possibly act either on the hypothalamus and/or the pituitary to affect pituitary and plasma levels of gonadotropins.
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PMID:The effect of subcutaneous injections of melatonin, arginine vasotocin, and related peptides on pituitary and plasma levels of luteinizing hormone, follicle-stimulating hormone, and prolactin in castrated adult male rats. 44 49

We have analyzed the plasminogen activator (PA) content of normal rodent mammary glands at different stages of the mammary life cycle and after exposing the animals to various hormones; we have also assessed the PA response of mammary explants to a variety of hormonal environments. Similar studies were performed on a limited number of primary mammary tumors. Plasminogen activator production was clearly correlated with mammary involution. A large but transient increase in enzyme content followed the initiation of involution in all glands, and the enzyme was produced by mammary cells, not by macrophages or granulocytes. Oxytocin, prolactin and hydrocortisone, which slowed or blocked involution, produced parallel effects on gland regression and PA synthesis. PA synthesis by explants in organ culture was induced by hormonal environments that fostered involution and repressed by those that promoted lactation. Mammary tumors produced much more PA than normal tissue both in vivo and in vitro, and distinct differences were found in the response of enzyme synthesis to hormones. The results reinforce the association of PA with tissue remodeling; show that the enzyme can be used as an indicator of cellular response to a wide range of hormones in both normal and malignant tissue; and suggest that observations of this type in organ culture may be of some value in predicting physiological responses in vivo.
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PMID:Mammary plasminogen activator: correlation with involution, hormonal modulation and comparison between normal and neoplastic tissue. 45 56

Oxytocin (OT) was measured by a specific and sensitive RIA in plasma and amniotic fluid throughout pregnancy. OT was detectable in 84.5% of 362 maternal plasma samples and showed a slow and fluctuating increase towards term with a significant sharp peak at 39 weeks of gestation. There was a highly significant correlation between mean plasma OT and the week of gestation (r = 0.5419, P less than 0.005). The minute to minute variability in plasma OT during pregnancy and labor in 7 subjects showed episodic release of OT with two or three spurts per 10 min, with the amplitude of the spurts being greater during labor. Serial maternal plasma OT throughout pregnancy in 10 patients revealed good concentrations of OT (greater than 10 pg/ml) in patients who subsequently had spontaneous labor and no intrapartum uterine dysfunction. Poor (less than 10 pg/ml) or undetectable OT levels were found in patients who subsequently developed intrapartum uterine dysfunction which necessitated cesarean section. OT was detectable in 89.7% or 87 amniotic fluid samples, with a mean +/- SE of 7.8 +/- 3.6 pg/ml at 14--15 weeks, 43.9 +/- 14.7 pg/ml at 40 weeks, and 30.8 +/- 10.5 pg/ml at 41--42 weeks. The significance of these findings is discussed in relation to the role and origin of OT in pregnancy and parturition.
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PMID:Oxytocin in maternal circulation and amniotic fluid during pregnancy. 46 76

1. The development of the hypothalamo-neurohypophysial system was studied using immunocytochemistry with various antisera : anti-neurophysin, anti-oxytocin, anti-vasopressin, anti-vasotocin and anti-somatostatin. 2. Immunocytochemical investigation shows that anti-vasopressin and anti-vasotocin sera react with both vasopressin and vasotocin, whereas the anti-oxytocin serum specifically reveals the oxytocin-containing structures (Fig. 1g, h, i). 3. Perikarya stained with anti-neurophysin, anti-vasopressin and anti-vasotocin sera can be seen from the 11th week of fetal life (Fig. 1a) first in the supra-optic nucleus (SON), then in the para-ventricular nucleus (PVN). Their axons reach the neural lobe as early as the 11th week (Fig. 1b, c). 4. Oxytocin-containing perikarya appear simultaneously in the PVN (Fig. 1e) and SON during the 13th week. 5. From the 16th week, neurons stained with the anti-somatostatin serum can be seen among the neurophysin-positive cell-bodies of the SON and PVN. 6. The various populations of magnocellular neurons show a significant increase in number, especially up to the 19th week, and an increase in their hormonal content up to birth.
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PMID:[Immunocytochemical study of the maturation of the hypothalamo-neuro-hypophysial axes in the human fetus (author's transl)]. 46 13

Plasma oxytocin concentrations were measured during late pregnancy, parturition and lactation in the miniature pig. Measurements were made of plasma oestradiol, oestrone and progesterone to determine whether there was any relationship between the concentrations of oxytocin and these steroids in the circulation. Plasma oxytocin concentrations were low or undetectable in late pregnancy. Rises of up to 68.8 mum./ml were seen at the time of delivery of the foetuses and at the expulsion of the placenta. The only steroid that seemed to relat to oxytocin release was progesterone. Oxytocin release was consistently seen when progesterone concentrations had fallen to below 10 ng/ml but no increase in concentration was observed while oestrone and oestradiol increased to their maximum concentrations of 3.86--11.6 and 0.43--0.70 ng/ml respectively. During lactation, when both oestrogen and progesterone concentrations were low, suckling caused the levels of oxytocin to increase to 7.4 muu./ml. These increases were greater during the first 2 weeks of lactation than later.
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PMID:Plasma oxytocin and steroid concentrations during late pregnancy, parturition and lactation in the miniature pig. 47 35

Management of 226 patients with previous low transverse cesarean section in a special obstetric clinic for high-risk pregnancies significantly and safely reduced the incidence of purely elective cesarean section to less than 10%. A substantial incidence (25%) of other high-risk factors dictating antepartum indicated cesarean section were found in this population. There was 38.5% incidence of vaginal delivery in 145 patients who underwent a trial of labor. Patients delivered vaginally followed a normal labor curve up to full dilatation. Oxytocin was required in three cases of prolonged second stage of labor and resulted in instrumental vaginal delivery in all instances. There were no uterine ruptures on vaginal exploration after delivery or at the time of repeat cesarean section during labor. There was no maternal death or perinatal loss. No justification for the present clinical practice of a 99% inicidence of elective repeat cesarean section could be found. Substantial savings in hospital cost, as well as a decreased number of diagnostic tests for the otherwise normal gravid woman, can be safely achieved.
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PMID:Management of pregnancy after cesarean section. 50 Jul 74

The action of synthetic oxytocin and Glanduphen, a neurohypophyseal extract preparation, on the diuresis of six heads of cattle in lactation was studied, following intraruminal application of water. Intravenous injection of something between 10 and 30 I.U. of oxytocin reduced diuresis by 54 per cent on average, within 30 minutes from treatment. Urine-borne Cl- -concentrations went up by 315 per cent on average and quantitative Cl- -secretion by 87 per cent. The values recorded in response to the administration of doses between 10 and 40 I.U. of Glanduphen were 44, 785, and 344 per cent. Additional application of Glanduphen within 30 minutes from oxytocin injection caused less pronounced inhibition of diuresis or even some activation of diuresis. Literature on renal effects of vasopressin and of oxytocin was analysed, in that context, and the conclusion was drawn that antidiuretic effects were recordable neither from man nor from animals unless they were exposed to excessive application of water. The same hormone preparations, however, caused increase of diuresis in thirty animals with low rates of diuresis and higher osmotic urine pressure. Rise in saluresis was a most common result of vasopressin or oxytocin administration and did in no way depend on the diuresis level.
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PMID:[Studies of the effect of synthetic oxytocin and neurohypophyseal extract on diuresis of water-laden cattle]. 54 12


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