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)

A case is reported of a 42-year-old woman who experienced uterine rupture in the course of a prostaglandin-induced abortion. The patient, gravida 5 para 4, was approximately 16 weeks pregnant upon admission. 8 cc (40 mg) of prostaglandin F2a and 50 cc apyrogenic 23.4% hypertonic saline were infused intraamniotically. Irregular uterine contractions developed shortly afterward, but at 35 hours no cervical changes or characteristic balooning of the lower uterus could be seen. At 39 hours the patient complained of cramps, and at 48 hours the uterus was tender, and the cervix was still unchanged but with bloody mucus at the os. On the assumption of intrauterine bleeding, a laparotomy was performed which revealed a 6 cm rent in the uterine fundus through which the uterine contents had passed into the abdominal cavity. There was a 3-cm-diameter leiomyoma close to the perforation. Complications such as this previously have been thought to be associated with the additional use of oxytocin; oxytocin, however, was not used in this case. It is concluded that a diagnosis of uterine rupture should be considered early whenever normal cervical and uterine changes do not follow instillation of the abortifacient. Further, because of the seriousness of such complications, midtrimester abortions should be induced only in a hospital setting.
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PMID:Uterine rupture: a complication of midtrimester abortion. 62 72

In light of the knowledge of the association between oxytocin administration and uterine rupture in late pregnancy, supraphysiologic doses of intravenous oxytocin are used by physicians to augment second trimester saline-induced abortions. According to the Center for Disease Control, this practice causing uterine rupturing is not unique to higher parities and can be fatal if not recognized. 2 case studies are reported. The 1st case, a 23-year-old woman (gravida 3, para 2), underwent saline instilled elective abortion at 18 menstrual weeks' gestation. Following removal of 200 cc of clear amniotic fluid from the uterus, an equal volume of 20% saline was instilled. 2 hours later, intravenous oxytocin was begun and an additional 400 mg of oxytocin was administered in the next 32 hours. 35 hours after instillation the patient had a thready pulse and blood pressure of 88/60, followed by stupor and cardiopulmonary arrest. After resuscitation a laparotomy disclosed an anterior paramedian laceration of the uterus. A hysterectomy was performed, the subsequent course was complicated, and the patient died on the 5th hospital day. In Case 2 a 29-year-old obese women (gravida 4, para 3) had an elective saline-instilled abortion at 20 menstrual weeks' gestation. After saline instillation the patient received intravenous oxytocin in the following amounts: 1) 60 mg; 2) 40 mg, with mild bleeding noted, and 3) 60 mg, followed by profuse vaginal bleeding. The fetus and the placenta were removed, and no detection of uterine rupture was made. The patient was transferred to another hospital, and died 5 hours later following multiple cardiopulmonary arrests. Rupture of the gravida uterus is defined as disruption of the uterine wall, occurring predominantly in the lower uterine segment. Uterine rupture and rupture during a term birth are probably analogous. The death-to-case rate for saline-induced abortions in the U.S. from 1972 to 1975 is .08 deaths/100,000, however, this rate would be higher if only saline-induced abortions receiving oxytocin were considered.
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PMID:Fatal uterine rupture during oxytocin-augmented, saline-induced abortion. 62 17

The 2-p-bromoacetylaminophenylalanine analogue of deamino-oxytoxin displayed some features of an irreversible inhibitor of oxytocin on rat uterus (long persistence of inhibitory effect, slow wash-out from the tissue). An isosteric analogue with a propionylamino group at the same position was, under similar experimental conditions, also an antagonist of oxytocin, but the features of an irreversible inhibitor were lacking. pA2 values of the two substances are between 6.5 and 6.9. The "irreversibility" of the former compound is concentration dependent and it is concluded that it cannot be entirely caused by a covalent binding of the inhibitor to the uterus receptor for oxytoxin. Like many other similar inhibitors, the substances display only an inefficient in vivo inhibition of the vasopressor effect of lysine vasopressin in rats.
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PMID:Some biological properties of an "irreversible" antagonist of neurohypophyseal hormones, deamino-[Phe(4-BrCH2CONH)2]-oxytocin, and its isosteric analogue, deamino-[Phe(4-CH3CH2CONH)2]-oxytocin. 65 39

Postpartum uterine pressures were measured in healthy women with an intrauterine microballoon before, during, and after administration of different concentrations of halothane or enflurane. Arterial blood samples for anesthetic levels were obtained at intervals. Frequency and intensity of contractions diminished markedly when blood levels exceeded the equivalent of 1/2 MAC (minimum alveolar anesthetic concentration which produces immobility in one-half of subjects exposed to a noxious stimulus) of nonpregnant adults, but normal patterns returned promptly on lightening of anesthesia. Response to 10 mU of oxytocin was suppressed at blood levels corresponding to between 3/4 and 1 MAC of the agents. Halothane and enflurane exert equipotent dose-related reversible effects on the activity of the full-term pregnant human uterus.
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PMID:Postpartum uterine pressures under halothane or enflurance anesthesia. 66 48

A 22 year old primigravida at 40+ weeks gestation had an i.v. induction of labour with 5-10 mU/min oxytocin for 3 h which resulted in fetal distress without bleeding at 5 cm dilatation at station -3, vertex transverse. At emergency Caesarean section an occult rupture of the uterus was found. Maternal height 168 cm, weight 71.0 kg. Fetal length 53 cm, weight 4080 g. The problems of spontaneous rupture of the uterus without detectable prior damage of the uterine wall are discussed.
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PMID:[A case of spontaneous rupture of the uterus (author's transl)]. 66 38

Effects of estradiol on the release of prostaglandin-like substance (PG) from rat uterus was investigated. The amount of PG released into a medium that did not contain oxytocin was decreased by estradiol, but the release of PG was remarkably increased by the addition of oxytocin. No significant correlation was found in the relationship between PG release and uterine contraction in uterus of either the ovariectomized rat and that of the estradiol-injected rat. The amount of PG released from the uterus of ovariectomized rat and the uterus of 6 hours after estradiol injection was decreased by indomethacin. The PG release promoting action of oxytocin observed in estradiol-injected rat uterus disappeared completely with treatment of phospholipase C.
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PMID:Effects of estradiol and oxytocin on the release of prostaglandin-like substance from isolated rat uterus. 74 8

Prostaglandin A is known to be an antihypertensive vasodepressor agent produced by the kidney and has the basic potentialities of a hormone. No information is available at present concerning its effect on the human pregnant uterus and whether it can be used as an oxytocic compound to induce labour. The uterine stimulating and labour inducing ability of PGA1 was evaluated in 10 cases; seven patients were suffering from pregnancy toxemia while three were normal pregnancies near full term. Cardiotocographic tracings showed that uterine activity was markedly stimulated to a degree sufficient to induce labour. Continuous i.v. infusions at a rate of 0.25-1.0 mug/Kgm/min given over a fixed period of only 6 hours resulted in delivery in all cases except one following the discontinuation of administration. Beneficial effects on blood pressure were observed in toxemic subjects. Potentially serious FHR patterns and occasional hypertonus during therapy were seen and stress the need for more information to evaluate the safety, optimum dosage and duration of infusion as well as the place of this approach in clinical practice for the management of pregnancy toxemia. The absence of antidiuretic effect, the hypotensive response and uterine stimulating property of PGA1 indicate a possible advantage in toxemia of pregnancy as compared to oxytocin infusions.
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PMID:Renal prostaglandins for induction of labour-a dual clinical advantage in toxemia of pregnancy. 78 55

A method for the preparation of N-maleoylamino acids and esters is reported. These compounds were shown to inhibit both the oxytocin-induced smooth muscle contraction in the isolated rat uterus and the vasopressin-induced water loss from the isolated toad bladder. The inhibitory ability of the maleimides in the toad bladder assay was found to be related to their corresponding partition coefficients by the equation: log 1/C = -0.055 (log P) 2 + 0.227 log P + 3.96. N-Maleoylamino acids can be coupled to peptides to form alkylating reagents which react rapidly with sulfhydryl groups. The synthesis of [1-(N-maleoylglycyl)cysteinyl]oxytocin (3) and [1=(N-maleoyl-11-aminoundecanoyl)cysteinyl]oxytocin (4) as potential affinity labeling reagents is described. These oxytocin analogs were shown to readily react with sulfhydryl-containing compounds; however, neither 3 nor 4 was seen to inhibit in the rat uterus assay at concentrations up to 3 times 10(-5)M. When tested on the mucosal and serosal surfaces of the toad bladder, assay inhibition was seen only on the mucosal surface. These results are discussed with respect to the possible existence of sulfhydryl groups at neurohypophyseal receptors.
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PMID:Alkylating derivatives of amino acids and peptides. Synthesis of N-maleoylamino acids, [1-(N-maleoylglycyl)cysteinyl]oxytocin. Effects on vasopressin-stimulated water loss from isolated toad bladder. 80 6

[4-Threonine, 7-glycine]oxytocin and [1-(L-2-hydroxy-3-mercaptopropanoic acid), 4-threonine, 7-glycine]oxytocin (hydroxy[Thr4, Gly7]oxytocin) were synthesized by a combination of solid-phase and classical methods of peptide synthesis. A protected octapeptide was synthesized by the solid-phase method and following ammonolysis and purification 1 + 8 couplings in solution were employed to furnish the required key nonapeptide and acyl octapeptide intermediates, respectively. [7-Glycine]oxytocin was prepared from a sample of the protected nonapeptide intermediate used in the original synthesis of this peptide. [7-Glycine]oxytocin has an oxytocic potency (O) of 93 +/- 4 units/mg and an antidiuretic potency (A) of 0.0056 +/- 0.0003 units/mg. It has an O/A ratio of 16 000. [4-Threonine, 7-glycine]oxytocin has an oxytocic potency of 166 +/- 4 units/mg and an antidiuretic potency of 0.002 +/- 0.0004 units/mg. Its O/A ratio is 83 000. Threonine substitution has thus brought about a substantial enhancement in oxytocic activity and a fivefold enhancement in O/A selectivity. Hydroxy [Thr4, Gly7]oxytocin has an oxytocic potency of 218 +/- 8 units/mg and antidiuretic potency of 0.0040 +/- 0.0005 units/mg. Its O/A ratio is thus 54 500. All three 7-glycine-substituted analogues exhibit a marked sensitivity to Mg2+ on the rat uterus assay ststem and in the presence of 0.5 mM Mg2+ had oxytocic potencies in the range of 900-1000 units/mg. Should these peptides exhibit enhanced oxytocic selectivity in humans, they might offer a greater margin of safety than oxytocin in those clinical stiuations in which the latter is currently employed.
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PMID:Synthesis and some pharmacological properties of [4-threonine, 7-glycine]oxytocin, [1-(L-2-hydroxy-3-mercaptopropanoic acid), 4-threonine, 7-glycine]oxytocin (hydroxy[Thr4, Gly7]oxytocin), and [7-Glycine]oxytocin, peptides with high oxytocic-antidiuretic selectivity. 83 10

Calcium antagonists are valuable pharmacological tools for the study of stimulussecretion and excitation-contraction coupling mechanisms. Two 2-substituted 3-dimethylamino-5,6-methylenedioxyindene hydrochlorides were tested for antagonism of the spasmogenic action of various agonists on isolated smooth muscle preparations. The 2-n-propyl and 2-n-butyl aminoindenes (5 X 10(-5) to 10(-4) M) blocked the spasmogenic action on the estrogen-treated rat uterus of prostaglandin E2 (10(-7) M), prostaglandin F2alpha tromethamine salt (10(-7) M), oxytocin (10(-3) U/ml), barium chloride (BaCl2-2H2O; 2.2 X 10(-4) M), acetylcholine chloride (10(-6) M) and ergonovine maleate (7.5 X 10(-4) M); they also blocked the contractile effect on the ileum of acetylcholine chloride (10(-6) M; rat) and histamine hydrochloride (10(-6) M; guinea pig). In further experiments on rat uterus using the agonists acetylcholine chloride (10(-6) M; which presumably acts by increasing influx of extracellular calcium into cells) and barium chloride (2.2 X 10(-4) M; which presumably contracts smooth muscle by releasing intracellular calcium), a progressive increase in extracellular calcium concentration (from 9 X 10(-4) to 7.2 X 10(-3) M CaCl2-2H2O) was paralleled by progressive reversal of the blockade produced by both 2-substituted aminoindene antagonists. In studies on the perfused bovine adrenal medulla, the 2-n-propyl aminoindene (10(-4) M) completely blocked the calcium-dependent catecholamine secretion evoked by 0.1 and 3.3 mM carbachol, without affecting the calcium-independent catecholamine secretion evoked by 33 mM acetaldehyde. These findings suggest that the aminoindene antagonists interfere with the action of calcium and that in smooth muscle the antagonism is at an intracellular site involved in excitation-contraction coupling.
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PMID:Pharmacological evaluation of new calcium antagonists: 2-substituted 3-dimethylamino-5,6-methylenedioxyindenes. 85 Jan 35


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