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 oxytocin-associated neurophysin concentration [( OT-RNP]) was used to evaluate the responsiveness of oxytocinergic neurons to an acute salt load in Long-Evans (LE) rats and Brattleboro homozygous (DI) rats. This responsiveness was compared with that of vasopressinergic neurons in LE rats as indexed by plasma vasopressin-associated neurophysin concentration [( VP-RNP]). Acute salt loading was induced by infusing 18% saline for 60 min into conscious, trained, chronically catheterized animals and plasma osmolality (Posm) and mean arterial pressure (MAP) were monitored. An increase in Posm was associated with a rise in [OT-RNP] and the relationship between delta [OT-RNP] and delta Posm was similar for both LE and DI rats over the first 40 min of infusion (21.6 and 19.7 fmol ml-1 mosm-1 kg-1, respectively). Although Posm continued to rise between 40 and 60 min infusion, [OT-RNP] actually fell slightly during this period in LE rats to a final elevation of 682 +/- 40 fmol/ml above initial values whereas [OT-RNP] in DI rats continued to rise to a final elevation of 1,927 +/- 288 fmol/ml above initial values at 60 min of infusion. The differences between these elevations at 60 min for LE and DI rats were highly significant (p less than 0.001). For LE rats, the increase of [OT-RNP] with Posm for the first 40 min of infusion was much greater than the increase in [VP-RNP] with the slope between delta [VP-RNP] and delta Posm being only 8.3 compared to 21.6 fmol ml-1 mosm-1 kg-1 in the case of delta [OT-RNP].(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Responsiveness of oxytocin-producing neurons to acute salt loading in rats: comparisons with vasopressin-producing neurons. 395 71

The responses of vasopressinergic neurons to acute salt loading and to graded hemorrhage were studied in rats under conscious and anesthetized conditions. Chronically cannulated rats were used in this study so that pre- and postanesthetic conditions could be studied in the same animals. Anesthesia induced by a combination of ketamine hydrochloride and pentobarbital sodium (Nembutal) did not cause a release of vasopressin-associated neurophysin (VP-RNP). In response to infusion of 18% saline, animals in the anesthetized state had significantly greater increases in plasma osmolality (Posmol) and plasma sodium concentration than animals in the conscious state. However, the rate of increase in plasma VP-RNP concentration ([VP-RNP]) as well as the relationship between [VP-RNP] and Posmol were not significantly different for the two states. Graded hemorrhage caused similar rates of increase in [VP-RNP] for animals under conscious and anesthetized conditions. These data suggest that anesthesia induced by ketamine plus pentobarbital sodium does not change the responsiveness of vasopressinergic neurons to acute salt loading and to graded hemorrhage.
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PMID:Function of vasopressinergic neurons in rats under conscious and anesthetized conditions. 397 Jan 92

A new case of oxytocin-induced water intoxication is reported in a 30 year old gravid woman. The severe symptoms of this uncommon complication are principally neurological; biological signs are a hyponatraemia with low plasma osmolality. Usually, biological and clinical signs are rapidly cleared up by treatment, but maternal death or neonatal water intoxication may occur. Such accidents must be prevented by clinical monitoring, watching out for alarm signals (oliguria is always found, resulting from the effect of oxytocin on the kidney), minimum fluid and proportional salt intakes, careful monitoring of oxytocin infusion rates, facilitated by the use of a constant flow-rate pump.
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PMID:[Acute water intoxication induced by oxytocin]. 407 15

A neurophysin has been isolated from ostrich neurohypophyses using acid acetone extraction, salt fractionation and Sephadex G-75 chromatography. The crude neurophysin eluting from the Sephadex G-75 column was subjected to a) reverse-phase HPLC followed by Sephadex G-75 chromatography, b) DEAE-Sephadex A-50 chromatography or c) isoelectric focusing. The different homogeneous ostrich neurophysin fractions so obtained were compared i.t.o. amino acid composition, spectral properties, N-terminal amino acid residues and PAGE. They all revealed a single N-terminal Ala residue and displayed spectral properties (A280/A260 less than 1) which are typical of mammalian neurophysin-like polypeptides. Ultracentrifugation studies on purified ostrich neurophysin over a range of concentrations revealed a reversible concentration dependent association behaviour characterized by the presence of dimeric complexes at higher concentrations. Partial sequencing from the N-terminus revealed the molecule to be VLDV-like. The purified molecule was also submitted to CNBr fragmentation.
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PMID:Isolation and characterization of a neurophysin from ostrich neurohypophyses. 407 82

Hypothalamic and neurophypophyseal levels of catecholamines and peptides were measured in spontaneous and deoxycorticosterone (DOCA)/salt hypertension. Catecholamines, norepinephrine, epinephrine and dopamine were measured by electrochemical detection while the peptides, vasopressin, oxytocin, luteinizing hormone-releasing hormone (LHRH), the enkephalins and somatostatin (SRIF) were measured by radioimmunoassay. Blood pressure was significantly elevated in both groups as compared to their controls. Marked changes in central neural peptides were observed in the SHR, while no differences were seen in DOCA/salt hypertension. Hypothalamic vasopressin, oxytocin, LHRH and SRIF were significantly decreased. In the posterior pituitary, enkephalins were increased twofold in the SHR. With regard to catecholamines, there was no change in hypothalamic content. However, a dramatic decrease in neurohypophyseal dopamine was observed in SHR. Plasma levels of vasopressin were significantly elevated in both types of hypertension while oxytocin was increased only in the DOCA/salt model. These result show that (1) a wide spectrum of neuroendocrine changes are associated with genetic hypertension, (2) there are CNS differences between DOCA/salt and spontaneous hypertension, and (3) central aminergic changes may be involved in th neuroendocrine alterations seen in the SHR.
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PMID:Central neural peptides and catecholamines in spontaneous and DOCA/salt hypertension. 611 62

Hepatocytes incubated with 25 muM [3H] taurocholate rapidly deplete the extracellular medium of [3H] taurocholate and achieve a steady-state level of intracellular bile salt within 15 min. Exposure of cells at steady state with extracellular taurocholate to the catecholamines norepinephrine or epinephrine results in release of 3H from the cells into the incubation medium; the 3H released represents almost exclusively unmetabolized [3H] taurocholate. The hierarchy of effectiveness of the catecholamines, norepinephrine congruent to epinephrine greater than phenylephrine much greater than isoproterenol, is indicative of an alpha-adrenergic mechanism. Induction of [3H] taurocholate release by norepinephrine is inhibited by the alpha-antagonists phenoxybenzamine and phentolamine and by chlorpromazine, but is not affected by the beta-antagonist propranolol, further supporting an alpha-adrenergic basis for this phenomenon. Arginine vasopressin, at concentrations of 1 X 10(-9) M and greater, also induces bile salt release. Classical alpha- and beta-antagonists have minimal effects on vasopressin induced bile salt release. While the peptide hormones angiotensin and oxytocin are, alone, relatively ineffective inducers of bile salt release, oxytocin potentiates the induction of bile salt release by vasopressin, suggesting complex interactions with membrane receptor function. Further studies assessing the interaction of sympathetic neurotransmitters and peptide hormones with bile salt transport and release in the hepatocyte may provide insight into the regulation of hepatic secretory function in the intact animal.
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PMID:Induction of taurocholate release from isolated rat hepatocytes in suspension by alpha-adrenergic agents and vasopressin: implications for control of bile salt secretion. 614 55

The axonal endoplasmic reticulum (ER) and synaptic-like (micro)vesicles within axon terminals of the neurohypophysis and their contribution to the secretory process in hypothalamo-neurohypophysial neurons have been investigated cytochemically in normal mice and in mice given 2% salt water to drink for stimulation of hormone synthesis in and release from these neurons. Cytochemical techniques included the peroxidase-antiperoxidase (PAP) immunocytochemical method for localization of neurophysin, wheat germ agglutinin-horseradish peroxidase (WGA-HRP) as a tracer for the anterograde axonal transport of membrane from within the perikaryon, and blood-borne native horseradish peroxidase (HRP) as a tracer for internalized axon terminal membrane. The primary antiserum employed was directed against neurophysins I and II, the carrier proteins for the peptide hormones oxytocin and vasopressin, respectively. PAP reaction product was observed over neurosecretory granules but never over the endoplasmic reticulum, microvesicles or other organelles in axons and terminals of the neurohypophysis. WGA-HRP was delivered extracellularly to cell bodies of paraventricular neurons by cerebral ventriculocisternal perfusion. Internalized perikaryal surface membrane tagged with WGA-HRP was recycled through the innermost Golgi saccule (GERL) from which neurosecretory granules were formed. The anterograde axonal transport of membrane-bound WGA-HRP was manifested within the neurosecretory granules; WGA-HRP did not label the axonal reticulum or terminal microvesicles in the neurohypophysis. Blood-borne native HRP endocytosed into neurohypophysial terminals was associated with a plethora of microvesicles measuring 40-70 nm in diameter and vacuoles similar in size to the 100-300-nm-wide neurosecretory granules. The microvesicles contributed to the formation of numerous vacuoles. The internalization of axon terminal membrane as microvesicles incorporating HRP was quantitatively greater than vacuoles in both salt-stressed and control mice. The results suggest that in the hypothalamo-neurohypophysial system of the mouse the axonal ER and terminal microvesicles are not involved in the transport, storage, and exocytosis of neurosecretory material and perhaps other molecules processed through the innermost Golgi saccule. Nevertheless, a prominent population of the microvesicles within axon terminals of the neurohypophysis does participate in the secretory process. These vesicles are involved directly in the internalization of the terminal surface membrane subsequent to release of secretory granule content.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Further studies of the secretory process in hypothalamo-neurohypophysial neurons: an analysis using immunocytochemistry, wheat germ agglutinin-peroxidase, and native peroxidase. 620 13

A post-proline cleaving enzyme and its endogenous inhibitor have been demonstrated to be present in sperm of the ascidian, Halocynthia roretzi. The enzyme was extracted with artificial sea water from frozen and thawed sperm and isolated from accompanying acrosin-like and chymotrypsin-like enzymes by DEAE-cellulose chromatography. It was then separated from the endogenous inhibitor by ammonium sulfate fractionation and DEAE-Sephacel chromatography. Three subsequent chromatographic operations using hydroxylapatite, Sephadex G-150 and Z-Gly-Pro-Leu-Gly-aminohexyl-Sepharose yielded the highly purified enzyme. The molecular weight and isoelectric point of the enzyme were estimated to be 66,000 and 5.5, respectively. The pH optimum of the activity was 7.0. The enzyme was inactivated with diisopropylphosphorofluoridate, phenylmethylsulfonyl fluoride, Z-Gly-Pro-chloromethyl ketone and sulfhydryl-directed reagents; these inhibitor susceptibilities were similar to those reported for the enzymes of mammalian origins. The ascidian enzyme hydrolyzed oxytocin, angiotensin II, luteinizing hormone releasing hormone and neurotensin at the carboxyl side of proline residues. The endogenous inhibitor was heat stable. The molecular weight of its main component was estimated to be about 8,000. The presence of salt at high concentrations weakened the enzyme-inhibitor interaction. Z-Gly-Pro-chloromethyl ketone inhibited fertilization of the ascidian, suggesting possible involvement of the post-proline cleaving enzyme in fertilization.
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PMID:Isolation and characterization of a post-proline cleaving enzyme and its inhibitor from sperm of the ascidian, Halocynthia roretzi. 636 Oct 7

Information from 2 recent books on the most common abortion techniques is presented. Menstrual aspiration can be performed up to 14 days after a missed period. A flexible plastic cannula 4-5 mm in diameter is passed through the cervix to the uterus, and the contents are evacuated using a syringe. Little dilatation is required and the procedure is done under local anesthesia. Aspiration through the 12th week is usually done under general anesthesia using a cannula and mechanical aspiration. A curette is used to assure that the abortion is complete. Local anesthesia is used in some places. From 12-16 weeks a combination of scraping and aspiration is used with general anesthesia and sometimes forceps. The uterine cervix requires greater dilatation. After 16 weeks the amniotic fluid is removed and a solution of salt and water is injected into the woman under local anesthesia. Contractions begin about 24 hours later. Labor may also be induced by oxytocin or prostaglandins which result in 8-15 hours of labor. This method of abortion probably causes the greatest amount of anxiety in the patient. Uterine scraping is described in the 2nd book as a procedure in which the cervix is progressively dilated with metal instruments of different sizes until it is sufficiently dilated to permit passage of the curette. Laminaria tents were previously placed in the cervix 24 hours prior to the abortion to achieve slow and progressive dilatation. General anesthesia is required because cervical dilatation is painful. In uterine aspiration the contents of the uterus are removed using tubes called Karmen cannulas. It is sometimes possible to avoid cervical dilatation by using thin cannulas, in which case general anesthesia may be avoided. After the aspiration the uterus may be scraped to assure the complete removal of the uterine contents. Prostaglandins may be used to initiate uterine contractions leading to expulsion of the uterine contents during the 2nd trimester of pregnancy. The procedure may cause significant side effects. Other procedures consist of injecting various substances into the uterine cavity during the 2nd trimester of pregnancy. Hysterotomy involves surgical opening of the abdomen and is analogous to cesarean section. Possible complications of an induced abortion include uterine perforation, bleeding, infection, and in extreme cases maternal death through sepsis. Medical attention should be sought in cases of hemorrhage, abdominal pain, fever, or general malaise after an induced abortion.
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PMID:[Literary but technical abortion]. 655 11

The neuropil located ventral to the SON was investigated by the use of immunoperoxidase staining for neurophysins, oxytocin and vasopressin, and electron microscopy. The study was performed in six groups of rats: 1) control; 2) infusion of isotonic saline into the CSF; 3) infusion of hypertonic saline into the CSF; 4) drinking hypertonic saline for 4 days; 5) same as group 4 but injection of colchicine into the CSF on second day of dehydration; 6) salt loading for 3 months. In the control rats the ventral neuropil contained a few immunoreactive processes, the general morphology of which was completely different from that of the neurosecretory axons emerging from the SON at its dorsal aspect. In rats of groups 3 to 6 the ventral processes (VP) became loaded with neurosecretory granules, whereas the perikarya and axons were depleted. Based on their general morphology and reactivity pattern it is suggested that the VP are dendrites. Most of these "dendrites" were embedded in a glial cushion formed by the processes of a particular type of marginal glia. Some of these "dendrites" enveloped an arteriole penetrating the optic tract. All VP were rich in synaptic contacts. The possibility that the VP of neurosecretory cells may be functionally related to the subarachnoid CSF and the arteriolar blood flow is discussed.
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PMID:Immunocytochemistry and ultrastructure of the neuropil located ventral to the rat supraoptic nucleus. 671 4


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