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 tissue culture model was established for the study of hypothalamic peptide synthesis and secretion. Microdissected explants of the paraventricular and supraoptic regions from Sprague-Dawley rats (neonates or young rats) were maintained in culture for up to 3 weeks. Studies were performed to evaluate vasopressin and oxytocin content (medium and tissue levels), immunocytochemical localization, and biosynthetic activity. Immunocytochemical staining for oxytocin, neurophysin, and neuron-specific enolase showed positive neurons in both the paraventricular and supraoptic cultures. In many cases, the neurons were large (30-40 microns) and bipolar, resembling the classic magnocellular neuron. Measurement of tissue and medium content showed the continued presence of vasopressin and oxytocin in the cultured explants. Even after 3 weeks, there were significant amounts of vasopressin present. Biosynthesis was evaluated by determining the incorporation of 35S-labeled cystine or cysteine into proteins and peptides. The medium and tissue extracts were separated by reverse-phase high-performance liquid chromatography. Results showed that most of the labeled peptides were released into the medium rather than stored. There were two labeled peaks in the medium, which chromatographically resembled native vasopressin and oxytocin. Treatment with a protein synthesis inhibitor, either puromycin or cycloheximide, resulted in a decrease in labeled peptides. A comparison of 35S-labeled cystine and cysteine showed that the latter was the label of choice, with significantly greater incorporation.
Hypertension 1986 Jun
PMID:Biochemical and immunochemical studies of supraoptic and paraventricular cultures. 372 56

A retrospective study was done on 525 infants who weighed more than 4,500 g. The rates of grand multiparity, diabetes mellitus, pregnancy-induced hypertension, deliveries in women over 35 years of age, placenta previa and weight gain of more than 15 kg were higher than in a control group weighing 2,500-4,000 g. The rates of delivery with instruments and cesarean section were also significantly higher. The main indication for cesarean section in the study group was cephalopelvic disproportion, while in the control group it was repeat cesarean section. Rates of postpartum hemorrhage, shoulder dystocia, oxytocin augmentation of labor and tears in the birth canal far exceeded those in the control group. Maternal and fetal morbidity and perinatal mortality were significantly higher than in the control group. The complications were due to a difficult second stage of labor. Delivery of the macrosomic fetus by cesarean section is highly recommended except for the subgroup of women who already delivered a macrosomic child.
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PMID:Complications associated with the macrosomic fetus. 373 62

A 28-year-old man with the chronic syndrome of Inappropriate antidiuretic hormone secretion and hypertension was found to have an olfactory neuroblastoma. We demonstrated evidence of elevated circulating arginine vasopressin levels, significantly elevated arginine vasopressin and vasopressin neurophysin levels in the tumor extract, and immunohistochemical staining for arginine vasopressin and vasopressin neurophysin in the tumor cells. The patient's clinical syndrome, including hypertension, resolved following subtotal removal of the tumor and radiation therapy. This study identified olfactory neuroblastoma as a definite cause of ectopic arginine vasopressin secretion causing the syndrome of inappropriate antidiuretic hormone secretion.
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PMID:Chronic syndrome of inappropriate antidiuretic hormone secretion and hypertension in a patient with olfactory neuroblastoma. Evidence of ectopic production of arginine vasopressin by the tumor. 375 13

Acetylcholinesterase (AChE) activity, and concentrations of monoamines, monoamine metabolites and oxytocin (OT) were measured in the cerebrospinal fluid (CSF) of sheep during late pregnancy, labour, parturition, vaginocervical stimulation, lamb separation and suckling. Concentrations of AChE, 4-hydroxy-3 methoxyphenylethan-1,2-diol (MHPG) and OT were significantly elevated during labour and parturition. OT levels were also significantly raised in cycling ewes given vaginocervical stimulation. Separation of the ewes from their lambs (0.5-2 h) caused significant increases in AChE and MHPG, but not in OT. During suckling, following reunion of the ewes and lambs, concentrations of AChE and OT were significantly raised. The dopamine metabolites 3,4-dihydroxyphenylacetic acid and homovanillic acid were significantly lower in CSF during late pregnancy than during parturition and post-partum. Intravenous injections of OT which produced high circulating levels of this hormone in plasma produced significant, but very small, increases in concentrations of OT in the CSF. Our results show that in the sheep, labour, parturition, suckling and vaginocervical stimulation provoke a release of OT in the brain similar to that in the peripheral circulation. Changes in CSF levels of AChE and MHPG during labour, parturition and lamb separation, but not during vaginocervical stimulation, may be related to stress or hypertension.
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PMID:Cerebrospinal fluid levels of acetylcholinesterase, monoamines and oxytocin during labour, parturition, vaginocervical stimulation, lamb separation and suckling in sheep. 379 90

The vasoconstrictor and vasopressor actions of vasopressin have been revealed in recent research through the use of highly specific and sensitive radioimmunoassays, employment of peptide antagonists, and comparison with an animal model which has hereditary absence of this hormone, the Brattleboro rat. Factors now known to modify the pressor effect of vasopressin are the baroreflexes, local vascular prostaglandin production, and a specific interaction with angiotensin II. In experimental models the volume retaining, but not the vasoconstrictor effect of vasopressin is necessary for mineralocorticoid-salt hypertension. Vasopressin contributes directly to the increase in arterial pressure of glycerol induced acute renal failure. In nephrectomized rats, plasma vasopressin is elevated and contributes directly to maintenance of pressure. Vasopressin antagonism may reduce arterial pressure in Goldblatt 1 and 2 kidney hypertension and in one genetic model, spontaneously hypertensive rat (SHR), but the peptide is not necessary for hypertension in these models. Plasma vasopressin is reduced in primary aldosteronism, but may be elevated in malignant hypertension. In essential hypertension, there is considerable disagreement among various studies in which plasma vasopressin, urine vasopressin excretion, platelet associated vasopressin, or vasopressin-neurophysin were measured as to whether there is evidence for increased secretion of vasopressin. Only preliminary studies of vasopressin antagonism in clinical hypertension have been reported. At present, there is no conclusive evidence that elevated vasopressin secretion occurs or is necessary for any form of clinical hypertension.
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PMID:The role of vasopressin in experimental and clinical hypertension. 388 2

Biochemical, cytochemical and immunological methods were used to compare the metabolic and neuroendocrine properties of the subfornical organ (SFO) with the hypothalamo-neurohypophysial system (HNS) in the rat. The SFO resembles the HNS in that both have (a) increased label incorporation into RNA during dehydration; (b) an intense reaction for glucose-6-phosphate dehydrogenase; (c) NADPH-diaphorase and the Type I pathway for hydrogen utilization from NADPH, presumably as part of the mixed-function oxidase system for the metabolism of endogenous substrates and xenobiotics; (d) immunoreactive vasopressin and oxytocin. Gel filtration of extracts of the SFO area using Sephadex G-25 chromatography resulted in immunoreactive peaks for both AVP and OT which were similar to synthetic hormones. One other fraction in the SFO extract, containing a substance(s) of higher molecular weight than AVP, was detected using the antiserum for AVP. The concentration of immunoreactive AVP in the SFO area was increased after colchicine, decreased by hypophysectomy, and unaltered by: (a) infusion (4.6 pg/min for 3 hr) or injection (1 or 6 ng) of AVP into the lateral cerebroventricle; (b) dehydration; (c) renin administered intracerebroventricularly; (d) pinealectomy; or (e) hypertension in the spontaneously hypertensive rat. In conclusion, cells in the SFO have specialized metabolic and neuroendocrine properties similar to the HNS. It can be inferred from these biochemical specializations that the SFO has metabolic and secretory activities.
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PMID:The subfornical organ: biochemical and neuroendocrine comparisons with the hypothalamo-neurohypophysial system. 402 8

Professor Brosens and colleagues (April 27, p.808) questions the safety of prostaglandins (PGs) for the induction of labor when pregnancy is complicated by hypertensive states, especially preeclampsia. Objections are based on the possibility that the uteroplacental bloodflow, which may already be compromised in these situations, could be further reduced by vasoconstrictive effects of the PGs on uterine, placental, and umbilical vessels. We have been using PGs extensively in this department and for the past year have been carrying out a double-blind trial of PGE2 and oxytocin by intravenous infusion after amniotomy for induction of labor in primigravidae. In 23 of the patients included thus far, labor was induced between 36 and 38 weeks because of moderate or severe preeclampsia. Of these, 12 have received oxytocin and 11 PGE2. In all cases, elective epidural analgesia has been employed and continuous fetal heartrate and intrauterine pressure recordings performed throughout. 1 patient in the group required an emergency cesarean section because of fetal distress; 2 others (1 from each group) were delivered by cesarean section because of failure to progress in labor. The remainder delivered vaginally with no evidence of increased incidence of fetal distress in the PG group. No perinatal deaths occurred. In an additional 18 primigravidae labor was induced at 36-38 weeks because of hypertensive complications of pregnancy by local PGE2 administration as previously described. These patients were assessed as clinically unfavorable for induction. 2 patients developed fetal distress and required cesarean sections; the others delivered vaginally. Experience with PGF2alpha is much less extensive but there is no reason to believe that this compound would behave differently, except with regard to maternal side effects. Thus it seems beneficial to use PGs for inducing labor in pregnancies complicated by hypertension and preeclampsia; no evidence of the suggested theoretical hazards has been seen. The suggested dangers may be questioned on 2 bases. It seems premature, based on existing knowledge, to infer that spiral arteries in hypertensive pregnancies are adversely affected by vasoconstrictor substances. Also, it is probable that high concentrations of PGs occur naturally in reproductive tissues and a rapid increase of PG in amniotic fluid occurs in spontaneous labors as well as those induced with oxytocin or PGs. Due caution must be exercised in using PGs where placental function may be impaired. The results-to-date which have been obtained with careful monitoring of the fetal heartrate and intrauterine pressure, show no evidence of adverse effects on the fetus as a result of PG use in preeclampsia and suggest they represent a valuable therapeutic agent in the management of this condition.
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PMID:Letter: Prostaglandins and pre-eclampsia. 413 36

This paper presents 2 cases of intrauterine death induced satisfactorily using intrauterine extraamniotic Prostin E2. The 1st case involved a 39-year old woman with severe hypertension and superimposed toxemia. She was admitted at 24 weeks with a blood pressure of 175/100 mm Hg, albuminuria, and edema. Ultrasonic biparietal measurement showed increasingly retarded fetal growth. Intrauterine death occured at 32 weeks. Labor was induced with intrauterine extraamniotic Prostin E2 introduced by a Foley catheter. This was the method of choice because of the patient's hypertension, albuminuria, and impaired renal function. The patient delivered uneventfully after 5 hours and 3 doses of 2 ml. There was no puerperal pyrexia. The 2nd case involved a 38-year old woman who suffered intrauterine death at 28 weeks due to severe Rhesus isoimmunization. Intravenous oxytocin and intravenous prostaglandin were initially used unsuccessfully to induce labor. Labor was induced rapidly using PGE2 via the intrauterine extraamniotic route. Full dilation was achieved with intravenous oxytocin. Induction delivery interval was 9 hours. There was no puerperal pyrexia. It is suggested that intrauterine but extraamniotic PGE2 is a reasonable method of induction in cases of intrauterine death because of the short induction delivery interval. Active management of intrauterine death is needed to avoid potentially serious complications, the most serious of which is the risk of coagulation disorder if the dead fetus is left in utero. Other important considerations are the patient's hospital beds. Intrauterine extraamniotic PGE2 may be safer and more effective than amniotomy and intravenous oxytocin and intraamniotic hypertonic saline because the membranes are left intact and because of the rapid induction time.
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PMID:Intrauterine death treated with intrauterine extra-amniotic prostaglandin E2. 446 77

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

To investigate the role of arginine vasopressin (AVP) in genetic hypertension, we measured 24-h urinary volume, osmolality, and 24-h AVP excretion, as well as pituitary and pineal AVP and oxytocin levels, in genetically hypertensive (LH), normotensive (LN), and low blood pressure (LL) 5-and 45-week-old female rats of the Lyon strains. We also determined vascular sensitivity to AVP, norepinephrine, and angiotensin II in 6- and 21-week-old rats. AVP secretion was increased in both LH and LL rats compared with LN controls. Previous reports of increased AVP secretion in spontaneously hypertensive rats have suggested that AVP might play a role in high blood pressure. The existence of a similar increase in LL rats indicates that genetic hypertension of LH rats is not related directly to their increased AVP secretion. Furthermore, the vascular sensitivity to AVP was not specifically enhanced in 21-week-old LH rats compared with LN and LL controls. This study provides evidence against a major role of vasopressin in the genesis and maintenance of high blood pressure in this model of experimental hypertension, and emphasizes that the choice of controls in such investigations is of crucial importance.
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PMID:Vasopressin and oxytocin in genetically hypertensive rats of the Lyon strain. 619 19


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