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)

Toad urinary bladders were mounted in Ussing-type chambers and volt-age-clamped. At nonzero voltages only, small fluctuations in current, delta I, and therefore in tissue conductance, delta Gt, were detected. These fluctuations were caused by the smooth muscle of the underlying tissue which could be monitored continuously and simultaneously with the current, I. Inhibition of the smooth muscle contraction with verapamil (2 X 10(-5) M) abolished the fluctuations in I and Gt. Amiloride (10(-4) M) had no significant effect on the magnitude of delta Gt, oxytocin increased Gt without affecting delta Gt, and mucosal hypertonicity produced by mannitol increased delta Gt. These results are consistent with the hypothesis that two parallel pathways exist for passive current flow across the toad urinary bladder: one, the cellular pathway, was not affected by smooth muscle activity; the other, the paracellular pathway, was the route whose conductance was altered by the action of the smooth muscle. Thus the relationship between the cellular and shunt conductances of the epithelium of the toad urinary bladder, under a variety of conditions, can be investigated by utilizing the effects of the movement of the smooth muscle.
J Membr Biol 1978 Dec 29
PMID:Cellular and shunt conductances of toad bladder epithelium. 11 Sep 41

Rabbits were anesthetized with urethane, and the concentration of 3',5' cyclic adenosine monophosphate (cAMP) in cerebrospinal fluid (CSF) was measured before and after injection into the cisterna magna of the following biologically active peptides and amines; adrenocorticotropin (ACTH), beta-melanocyte-stimulating hormone (beta-MSH), choroid plexus peptide IIF, arginine vasopressin, oxytocin, glucagon, epinephrine, serotonin, histamine, and acetylcholine. Only epinephrine and the lipolytic-melanotropic peptides ACTH, beta-MSH, and IIF influenced cAMP. Five to 500 mug ACTH caused a 3 to 10X increase in cAMP within 30 min; the concentration of nucleotide returned to baseline within 60-90 min after 5 or 50 mug, and remained elevated for at least 120 min after 500 mug. Effects of the same magnitude and tempo as those caused by 5 to 500 mug ACTH were produced by .1 to 10 mug beta-MSH and 5 to 500 mug IIF. Epinephrine at doses of 5 to 500 mug caused rises in cAMP of similar degree as the same dose of ACTH or peptide IIF, but the peak value was not reached until 60 to 90 min after injection.
Endocrinology 1975 Dec
PMID:Effect of intrathecal injection of melanotropic-lipolytic peptides on the concentration of 3',5' cyclic adenosine monophosphate in cerebrospinal fluid. 17 24

Rat and bovine adrenal cortical microsomal fractions isolated at 27,000 x g and 105,000 x g accumulated Ca2+ by a nonmitochondrial, ATP-dependent uptake system that was stimulated by ammonium oxalate. ACTH (2 mU/ml) significantly increased Ca2+ uptake in bovine adrenal cortical microsomes and in adrenal microsomes from acutely hypophysectomized rats, but only when the hormone was preincubated with intact tissue and not when it was added after homogenization. ACTH did not stimulate C2+ uptake in adrenal microsomes isolated from nonhypophysectomized, ether-stressed rats, in which basal Ca2+ uptake was higher than that observed in microsomes from hypophysectomized animals. The peptides oxytocin, insulin, and TSH did not stimulate Ca2+ uptake by adrenal cortical microsomes. ACTH preincubated with intact tissue had no effect on Ca2+ uptake in microsomes from liver, kidney, esophagus, or aorta. cAMP, 5'-AMP, and several other nucleotides, nucleosides, and related compounds stimulated adrenal cortical microsomal Ca2+ uptake by as much as 540% of control. The stimulatory effects of nucleotides, unlike those of ACTH, were apparent even when the agents were added after homogenization. However, like ACTH, the nucleotides were unable to stimulate Ca2+ uptake when they were added to isolated membrane vesicles during Ca2+ uptake measurements. It is suggested that the microsomal Ca2+ uptake system may respond to physiological stimulants and regulate Ca2+ availability in the intact cell.
Endocrinology 1978 Dec
PMID:The effect of adrenocorticotropin and nucleotides on Ca2+ uptake in adrenal cortical microsomal vesicles. 21 5

Acceleration patterns of the fetal heart rate, or a normal heart rate during spontaneous contractions, were used as a short weekly screening test to evaluate fetal well-being in 1102 high-risk pregnancies. When accelerations or contractions were absent during the initial screening, oxytocin was administered to stimulate uterine contractions. The mean duration of the antenatal monitoring was 18.5 min when the initial antenatal monitoring was normal, but 38.8 min when the initial results were uncertain. Oxytocin was administered to 38% of patients. This reduced the number of occasions where the diagnosis was uncertain from 46.6% to 12%. Patients with uncertain antenatal fetal monitoring had significantly more late decelerations during labor as well as newborns with low Apgar scores when compared to those with normal antenatal monitoring. Patients with abnormal antenatal monitoring (positive stress test) had significantly more low 5-min Apgar scores, late decelerations during labor and growth-retarded infants than the patients with normal antenatal fetal monitoring. Only 1 intrauterine death occurred within 7 days of a normal antenatal heart rate recording. No preventable fetal deaths occurred when antenatal monitoring demonstrated an acceleration pattern of the fetal heart rate.
Eur J Obstet Gynecol Reprod Biol 1979 Dec
PMID:Combined (stressed and non-stressed) antenatal fetal heart rate monitoring. 26 1

Although the hypothesis that vasopressin and its associated neurophysin are synthesized together in one macromolecular common precursor was put forward more than a decade ago, direct conformation of this hypothesis has been lacking. A [35S]cysteine-labeled putative precursor for vasopressin-related neurophysin (Mr 20,000, pI 6.1) has been isolated from the supraoptic nuclei of rats. This precursor was subjected to limited proteolysis with trypsin which produced a Mr 10,000 protein and peptide products. The former was identified as neurophysin on the basis of its pH-dependent affinity for vasopressin and its behavior in isoelectric focusing systems (pI 4.6-4.8). The tryptic peptides proved to be vasopressin-like because they: (i) were rich in cysteine, (ii) comigrated with vasopressin on gel filtration columns in 6 M guanidine HCl, (iii) bound to a neurophysin-Sepharose affinity column at pH 5.7, and (iv) were recognized by antibodies against vasopressin. These data on the Mr 20,000, pI 6.1 protein represent direct experimental evidence for a candidate for the common precursor of vasopressin and neurophysin. We propose that this common precursor be called "propressophysin."
Proc Natl Acad Sci U S A 1979 Dec
PMID:Trypsin liberates an arginine vasopressin-like peptide and neurophysin from a Mr 20,000 putative common precursor. 29 5

Oxytocin produces uterine contractions and milk ejection, functions related to parturition and nuturing. Studies were conducted to determine if this peptide, native to the brain and the posterior pituitary gland, plays a role in the induction of maternal behavior. Intact virgin female rats were given 0.4 mug of oxytocin, 0.4 mug of [Arg(8)]vasopressin, or saline through lateral ventricular cannulae. Forty-two percent of intact rats receiving oxytocin displayed full maternal behavior towards foster pups. None of the saline- or vasopressin-treated animals displayed full maternal behavior. Criteria in five behavioral categories had to be fulfilled by an animal within 2 hr of injection for its behavior to be considered fully maternal. When partial maternal responses were considered, oxytocin was significantly more effective than saline and marginally more effective than vasopressin. Five animals responding fully maternally after oxytocin injection were allowed to stay with pups for 10 days. All five continued to display full maternal behavior during this time. Nearly all animals that responded fully maternally to oxytocin injection were in the last day of diestrus or in proestrus or estrus. This suggested that elevated or recently elevated levels of estrogen may be necessary for the induction of full maternal behavior by oxytocin. Twenty-seven virgin female rats were ovariectomized and given either 100 mug of estradiol benzoate per kg in oil subcutaneously or oil alone immediately after operation. Forty-eight hours later, all animals received 0.4 mug of oxytocin intracerebroventricularly. Eleven of 13 estrogen-primed animals became fully maternal; none of 14 nonprimed animals became fully maternal.
Proc Natl Acad Sci U S A 1979 Dec
PMID:Induction of maternal behavior in virgin rats after intracerebroventricular administration of oxytocin. 29 52

Recent studies in rats suggest that vasopressin- and oxytocin-secreting neurons in supraoptic nuclei and paraventricular nuclei of the hypothalamus show two different patterns of activity: one a "bursting" or rhythmic pattern and the other, irregular continuous discharges. This possibility was investigated in cats and dogs anesthetized with chloralose or Nembutal by recording electrical activity of single supraoptic and paraventricular neurons. Only some of the "identified" neurosecretory cells showed rhythmic, intermittent discharges ("bursting" cells in rats); the majority showed an irregular continuous firing pattern. Furthermore, the pattern of discharge sometimes changed from one ot the other during long periods of observation. This occurred without apparent stimulus in certain instances; in others, the rhythmic firing was associated with fluctuation in blood pressure and heart rate and was likely to be caused by changes in baroreceptor activity. Possible origins of rhythmic discharges and the physiological importance of such patterns in terms of hormone secretion are discussed.
Proc Natl Acad Sci U S A 1979 Dec
PMID:Rhythmic patterns of discharge in hypothalamic neurosecretory neurons of cats and dogs. 29 55

This study was conducted to determine whether combining prostaglandin (PG) and hypertonic saline augmented with oxytocin solution can be used in the management of second-trimester abortion to minimize the complications and side effects associated with the separate administration of each component. A total of 385 2nd-trimester pregnant patients (from the Montefiore Morrissania affiliated hospital and Mount Sinai Hospital of New York City) with gestational age 16 to 24 weeks were assigned randomly to 4 groups: Group 1 (PFG2a 20 mg + 100 ml 5% NaCl injected intraamniotically with no amniotic fluid removed); Group 2 (PGF2a 20 mg + 100 ml 10% NaCL (10g) injected intraamniotically and with no amniotic fluid removed; Group 3 (PGF2a 20 mg + 25 ml 20% NaCl injected intraamniotically and with no amniotic fluid removed; and Group 4 (PGF2a 20 mg + 100 ml 10% NaCL injected intraamniotically and with 100 ml amniotic fluid removed. The standard aseptic transabdominal amniocentesis with an 18-gauge needle and polyethylene catheter was used to administer the abortifacients. Success rate of the procedure was 98.97%. Instillation abortion interval ranged from 15.33 to 20.67 hours (Table 2). Of the 4 dosage schedules, Group 3 exhibited the most satisfactory results, with 15.33 hours as the average instillation abortion interval. Side effects were minimal. This study shows that the combination PG + NaCL augmented by oxytocin is one of the best available approaches to the management of 2nd-trimester abortions. The more amniotic fluid removed, the shorter the instillation abortion interval. Incomplete abortions were between 32 to 48.78%; the incidence was higher in cases where more amniotic fluids were removed.
Eur J Obstet Gynecol Reprod Biol 1979 Dec
PMID:Use of prostaglandin, hypertonic saline and oxytocin for second-trimester abortion. 29 62

Partly purified rat neurophysin was tested for its possible natriuretic activity in acutely hypophysectomized saline-loaded rats (hypophysectomized 2 h prior to saline infusion). Such animals were unable to excrete the saline load. When partly purified rat neurophysin was injected i. p. in a dose of 40 microgram per animal (which corresponds to its content in one rat posterior pituitary) before saline loading, the sodium excretion was not different from that found in acutely hypophysectomized animals, but it was significantly lower than in normal saline-loaded rats. It was concluded that any apparent natriuretic effect of rat neurophysin could not be established by the present experiments under the experimental conditions used.
Endocrinol Exp 1977 Dec
PMID:Failure to demonstrate a natriuretic effect of neurophysin in rats. 30 43

Postpartum hemorrhage is a common and serious complication of the third stage of labor resulting in anemia and increased morbidity in the puerperium. Administration of uterotonic drugs and suitable mechanical assistance in delivery of the placenta may significantly reduce this hazard. Ergometrine and oxytocin have been used for a long time in markedly different doses and by various routes of administration with varying success. In order to compare these two oxytocics with regard to their hemostatic effects as well as their possible interference with the physiologic placental separation mechanism, three groups (ergometrine, oxytocin, and control) of women have been studied during a 2-year period. Ergometrine (0.2 mg) and oxytocin (10 IU) administered in the stated doses and as single intravenous injections are comparable with regard to hemostatic efficiency, but oxytocin seems to promote placental separation and expulsion better and thereby reduces the risk of partial retention and trapping with bleeding reguiring further emergency measures as a frequent consequence.
Obstet Gynecol 1978 Dec
PMID:Active pharmacologic management of the third stage of labor. A comparison of oxytocin and ergometrine. 31 May 30


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