Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recordings of electrical activity of the oviduct and uterus were obtained during three oestrous cycles in cows fitted with an extra-cellular multi-electrode assembly. The stages of the cycle were identified by the appearance of the cervico-vaginal secretions and changes in the peripheral plasma level of progesterone were determined by radioimmunoassay. A gradual transition from local non-propagating electrical activity to propagating electrical activity with increase in the duration of contractions and then of their amplitude occurred 48 hr before the onset of oestrus. The transition coincided with a rapid decrease in progesterone level from 5 to 10 ng/ml to less than 0-1 to 0-4 ng/ml. This phenomenon was recorded from all uterine electrode sites, but was most marked at the uterotubal junction. Two days before oestrus, trains of potentials and bursts of activity became progressively grouped, apparently randomly, into prolonged phases in the distal portion of the oviduct and over the entire myometrium. During oestrus, the phases of activity became synchronized at these sites and both their amplitude and frequency reached a maximum. The strength but not the frequency of the phases diminished progressively 3 days after oestrus, followed by relative inactivity. The last remaining zone of activity was the uterotubal junction. During oestrus, the activities of the oviduct and the uterus were modified by oxytocin and adrenaline, the effect of the former being more marked on the uterus and that of the latter on the oviduct.
 ...
PMID:Motility of the oviduct and uterus of the cow during the oestrous cycle. 116 10

Authors report about 504 oxytocin infusions after amniotomy or spontaneous rupture of membranes without possibility of cardiotokography. The rate of success by a 12-hour-limit is 91,9 per cent, by a 24-hour-limit 95,2 per cent. It was observed a superior rate of obstetric operations, post-partum haemorrhages and 3 cases of uterus rupture following hypersensitivity. Intravenous oxytocin infusion reduced the time of delivery. After combinating induction of labour childrens have an acceptable general condition, recorded by Apgar-score. Simultaneous induction of labour by oxytocin infusion is a high-risk proceeding in obstetric hospitals without possibility of cardiotokography. However, a renunciation of this method in default of alternatives is not accept.
 ...
PMID:[Combined labor induction in the small hospital]. 118 80

The electrical activity of the whole genital tract of the rabbit was recorded by means of chronically implanted electrodes after section of the uterotubal junction on one side. When the junction was intact, the activity of the isthmus and that of the proximal uterine horn occurred almost simultaneously, but uterine activity decreased after the junction was cut. During the preovulatory phase and also after administration of HCG, synchronos activity due to adrenergic drugs, smoke or oxytocin persisted on both sides of the uterotubal junction. Hypersensitivity of the isthmus and the proximal segment of the uterine horn was recorded on the cut side after ovariectomy. The concept of a local control mechanism in the region of the uterotubal junction with a positive control of the uterus by the oviduct is suggested.
 ...
PMID:Relationship between the electrical activity of the oviduct and the uterus of the rabbit in vivo. 119 58

A substance possessing milk-ejecting activity has been isolated from an acetone powder preparation of bovine posterior pituitary glands by Sephadex G-25 chromatography of the neurophysin-neurohypophysial hormone complex. While the material possessed an oxytocic activity of 2.8 IU/mg as measured on the isolated rat uterus, the milk-ejecting activity was more than three fold greater, 9.6 IU/mg. The peptide had an antidiuretic activity of 0.133 IU/mg and a pressor activity of 0.083 IU/mg. Neither the uterine-stimulating action nor the pressor activity was destroyed by incubating the peptide with 0.01 M sodium thioglycollate at 65 degrees C for 5 min. The oxytocic activity was antagonized neither by 1.4 X 10(-6) M atropine nor 3.3 X 10(-7) M phenoxybenzamine.
 ...
PMID:Isolation and some observations of the properties of a bovine neurohypophysial milk-ejecting factor. 122 14

The complications accompanying the various methods of abortion as studied in different surveys are reported. In studies of dilation and curettage (D and C) and vaccuum aspiration (VA), lethality ranges from .5 to 2.9 deaths/100,000 cases. Metrorrhagia occurred in 2.5-6% of the D and C cases studied and in 2.9-3.5% of the VA cases. The bleeding was accompanied by infection in most cases where abortive tissue remained in the uterus, which occured in .4-.8% of the D and C cases and in .6-.9% of the VA cases studied. Postabortive bleeding occurred through the 10th day in up to 25% of the patients and was related to the length of the gestation period before abortion. Pelvic infection, mostly of the endometrium, occurred in about 1.4% of the D and C patients and in .3-1.2% of the VA patients. 1.4% of the D and C patients and .6% of the VA patients experienced a rise in body temperature as the only complication of abortion. Perforation of the uterus occurred in about .8% of the D and C patients and in .1-.6% of VA patients. Lesions of the cervix had to be sutured in .1% of the D and C group and .3% of the VA group. Saline instillation, used for abortions in the second trimest er, had a mortality rate of about 20/100,000 cases. Since the success rate of saline instillation is 90-98%, complications are more frequent, often requiring treatment with oxytocin or curettage. Extensive bleeding occurred in 2.3-4%. Curettage of the placenta was required in about 2.1-16.9% of the cases. Pelvic inflammation occurred in about 2.5% and temperature elevation in 1-3.4%. Abdominal hysterotomies had a lethality of 208/100,000. Pelvic hemorrhage occurred in 31%, inflammation in 4.7%, temperature elevation in 13%, and febrile reactions in 31% of the abdominal hysterotomies studied. It is necessary to establish international definitions of abortion complications for better documentation, and postoperative observations should be recorded more conscientiously.
 ...
PMID:[Acute complications of abortion]. 125 2

The motility of the isolated Cricetus auratus uterus was studied and compared to that of other species. Oxitocyn, epinephrine, norepinephrine, histamine, 5-hydroxy-tryptamine and acetylcholine were used as spasmogen agents. There was not contractil response with epinephrine or nor-epinephrine. Histamine reduced basal tonus. There was contraction with acetylcholine, oxytocin and 5-hydroxy-tryptamine. Cricetus auratus uterus appeared more sensitive when the contraction was registered by the isometric method. No taquifilaxy was produced by 5-hydroxy-tryptamine, as opposed to such effect in rat uterus. The Cricetus auratus uterus has, therefore, shown similar reactivity to that of rat, but different from rabbit and guinea-pig.
 ...
PMID:[Pharmacological reactivity in cricetus aureus uterus (author's transl)]. 125 67

The substitution of the 4-glutamine of oxytocin by a lipophilic aliphatic amino acid leucine yields [4-Leu] oxytocin which possesses natriuretic-diuretic anti-arginine-vasopressin (anti-ADH) activities. Alkyl substitutions of the beta-carbon of the 1 half-cystine of oxytocin yield a series of antioxytocin analogs which inhibit the uterotonic response to oxytocin. In this paper, the results of our further investigations on the molecular requirements for natriuretic, anti-ADH and antioxytocic activities of these peptides are reported. A total of 12 analogs of oxytocin and lysine-vasopressin (LVP) with leucine and/or beta-carbon alkyl substitutions were studied. Our findings reveal that the effect of 4-leucine substitution may not be to enhance the natriuretic activity but rather to abolish the antidiuretic activity of oxytocin. The lack of antidiuretic activity of these 4-leucine analogs makes it possible to unmask the intrinsic natriuretic activity of these peptides at the high dose level. Structure-activity correlations suggest that the oxytocin molecule may be the optimal requirement for natriuretic activity of these peptides. Substitution of 4-glutamine by lipophilic aromatic phenylalanine yields [4-Phe] oxytocin which possesses anti-ADH activity with little or no natriuretic activity. The "hybrid" antioxytocin and anti-ADH molecules, beta-carbon alkyl and 4-leucine substituted analogs did not possess enhanced antihormone activity. Although they had antioxytocic and antipressor activities, they were less potent than their respective singly alkyl substituted analogs. Furthermore, they had no demonstrable anti-ADH activity. The single alkyl substituted oxytocin and LVP also had no anti-ADH activity. It therefore appears that beta-carbon alkyl substitution had different effects on activities depending on the morphological features and the functions of the target cell. In target cells of contractile smooth muscles (uterus and vascular), the alkyl substituted analogs had no intrinsic activity but retained a relatively high receptor affinity to become effective antagonists to the natural hormone. On the other hand, in target cells of the renal tubule which are noncontractile epithelial cells, both intrinsic activity and receptor affinity were reduced or abolished. Thus none of these alkyl substituted analogs possessed more than very slight antidiuretic activity, and none had any natriuretic or anti-ADH activity.
 ...
PMID:An investigation of the natriuretic, antidiuretic and oxytocic actions of neurohypophysial hormones and related peptides: delineation of separate mechanisms of action and assessment of molecular requirements. 126 21

A review of 50 cases of ruptured uterus revealed that important measures to prevent this serious complication are: good antenatal care; careful attention to patients who have had a previous Caesarean section; the correct management of cephalopelvic disproportion in the multigravida; the recognition of the serious hazards of internal version in the management of transverse lie; and careful attention to detail in the use of oxytocin in the multigravida. The factors that were regarded as critical in maintaining a low maternal mortality rate in rupture of the uterus are also reviewed.
 ...
PMID:Rupture of the uterus: the preventable factors. 126 47

Smooth muscle cells normally do not possess fast Na+ channels, but inward current is carried through two types of Ca2+ channels: slow (L-type) Ca2+ channels and fast (T-type) Ca2+ channels. Using whole-cell voltage clamp of single smooth muscle cells isolated from the longitudinal layer of 18-day pregnant rat uterus, depolarizing pulses, applied from a holding potential of -90 mV, evoked two types of inward current, fast and slow [8]. The fast inward current decayed within 30 ms, depended on [Na]o, and was inhibited by TTX (K0.5 = 27 nM). The slow inward current decayed slowly, was dependent on [Ca]o, and was inhibited by nifedipine. These results suggest that the fast inward current is a fast Na+ channel current, and that the slow inward current is a Ca2+ slow channel current. A fast-inactivating Ca2+ channel current was not evident. Thus, the ion channels which generate inward currents in pregnant rat uterine cells are TTX-sensitive fast Na+ channels and dihydropyridine-sensitive slow Ca2+ channels. The number of fast Na+ channels increased during gestation. The averaged current density increased from 0 on day 5, to 0.19 on day 9, to 0.56 on day 14, to 0.90 on day 18, and to 0.86 pA/pF on day 21. This almost linear increase occurs because of an increase in the fraction of cells which possess fast Na+ channels, and it is suggested that the fast Na+ current may be involved in spread of excitation. The Ca2+ channel current density also was higher during the latter half of gestation. These results indicate that the fast Na+ channels and Ca2+ slow channels in myometrium become more numerous as term approaches, and may facilitate parturition. Isoproterenol (beta-agonist) did not affect either ICa(s) or INa(f), whereas Mg2+ (K0.5 of 12 mM) and nifedipine (K0.5 of 3.3 nM) depressed ICa(s). Oxytocin had no effect on INa(f) and actually depressed ICa(s) to a small extent. Therefore, the tocolytic action of beta-agonists cannot be explained by an inhibition of ICa(s), whereas that of Mg2+ can be so explained. The stimulating action of oxytocin on uterine contractions is not due to stimulation of ICa(s). Figure 11 summarizes the possible mechanisms by which uterine contractility can be modulated. In contrast to vascular smooth muscle, neither ISO nor adenosine, which produce elevation of cyclic AMP, affected ICa and INa. Therefore, no arrow can be drawn between cA-PK/cG-PK and the Ca2+ slow channel.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Fast Na+ channels and slow Ca2+ current in smooth muscle from pregnant rat uterus. 128 Dec 64

To measure cholinergic, adrenergic and tryptaminergic receptor activity of formaldehyde (HCHO) in rat uterus, albino rats were treated with 5 and 10 mg/kg, ip HCHO for 30 days. Acetylcholine (ACh) in doses 1.33, 2 and 3 micrograms/ml produced mild to moderate contraction of isolated rat uterus in control group. HCHO had no effect on isolated rat uterus per se, however it reduced ACh and carbachol induced contraction and presence of adrenaline influences in respect of ACh and carbachol activity. Adrenaline per se had no effect in control preparations, but reduced carbachol induced contraction. Propranolol had no effect on rat uterus; but its presence in the bathing medium increased activity of adrenaline. 5-Hydroxytryptamine (5-HT) had no effect of its own on isolated rat uterus but its presence in the bathing medium enhanced contractions of carbachol and oxytocin.
 ...
PMID:In vitro study of rat uterus after chronic formaldehyde exposure. 129 16


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>