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)

The effect of ovine trophoblast protein-one (oTP-1) on endometrial protein secretion was examined by using a dual radioisotope technique in which 3H- and 35S-methionine were employed to measure relative rates of protein release into the medium by endometrial explant cultures (Exp. I). Endometrium (200 mg) from Day (D) 12 of the cycle was cultured with either 5 micrograms/ml oTP-1, 5 micrograms/ml bovine serum albumin (BSA) or 1 mM dibutyryl cyclic adenosine 3',5'-monophosphate (DbcAMP). Culture media from control BSA and treated explant cultures were mixed. Proteins were separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and detected by fluorography. Individual protein spots were punched from gels, extracted, and their radioactive content measured. Ratios of 3H:35S were used to determine treatment effects. In Experiment II, 3H- and 14C-leucine were used for the dual radiolabel, and the DbcAMP treatment was omitted. In both experiments, a protein having a molecular weight (Mr) of about 70,000 and a pI approximately equal to 4 was increased (p less than 0.01) 200-400% by oTP-1. Secretion of several other endometrial proteins was also amplified in the presence of oTP-1. The polypeptides that increased in response to oTP-1 were inhibited by DbcAMP, and vica versa. In Experiment III, endometrial explants from D12 cyclic ewes were cultured for 4 h with either 5 micrograms/ml oTP-1 or 5 micrograms/ml BSA to determine whether oTP-1 influenced concentrations of 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP). Concentrations of cAMP in oTP-1-treated endometrium were lower (p less than 0.1) than in BSA-treated endometrium (0.29 vs. 0.41 pmoles/mg tissue, respectively). Levels of cGMP were unaffected by oTP-1. In Experiment IV, endometrium from D14 of the cycle was incubated in medium alone or in medium containing either 2 micrograms/ml oTP-1, 1 microgram/ml oxytocin (OXY), or oTP-1-plus-OXY. None of the treatments significantly affected cAMP levels. In Experiment V, D16 endometrium was collected from pregnant and nonpregnant ewes that had received either 0 or 10 IU OXY i.v. cAMP was higher (p less than 0.01) in endometrium from pregnant ewes compared to nonpregnant ewes (27.9 vs. 13.0 pmoles/mg tissue, respectively), but OXY had no detectable effect on endometrial content of cAMP in either nonpregnant or pregnant ewes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The effect of ovine trophoblast protein-one on endometrial protein secretion and cyclic nucleotides. 344 99

1. The concentration of serum albumin in rat milk, rat serum, the stomach contents of suckling rats and mammary homogenates has been measured. 2. Serum albumin in expressed milk ranges in concentration between 3.5 and 6 mg/ml and amounts to an average of 4-5 mg/100 mg total protein whereas, in the stomach contents of suckling rats, serum albumin was 3.2 mg/100 mg total protein. 3. Corresponding concentrations of a second soluble milk protein, alpha-lactalbumin, were 2.9 mg/100 mg total protein in the milk and 1.2 mg/100 mg total protein in the stomach contents. 4. Serum albumin is a major protein in mammary homogenates at 10 mg/100 mg total soluble protein and the calculated total mammary pool of albumin amounts to 110 mg/rat. 5. There was a significant negative correlation between the serum albumin concentration and the ratio of potassium to sodium ions in milk samples obtained from rats milked with varying oxytocin treatments. 6. No evidence for albumin mRNA could be detected when mammary total RNA was probed with a complementary DNA (cDNA) for rat albumin. 7. The data are consistent with albumin being a major whey protein in the rat, it being synthesized at an extramammary site and transferred to the milk space by a paracellular mechanism from an extravascular mammary pool rather than directly from the serum.
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PMID:Serum albumin secretion in rat milk. 344 53

Vasoactive intestinal polypeptide (VIP) was infused into the aorta of pentobarbitone-anesthetized rats (n = 12) in stepwise increasing doses of 0.001 to 10 micrograms/rat at rates varying from 0.3 pmol/min/kg to 3000 pmol/min/kg over 3 min. Blood was withdrawn from the vena cava inferior for the measurement of oxytocin (OT) and vasopressin (AVP) by RIA. The loss of blood was compensated for by infusion of isotonic saline (0.9% NaCl with 0.5% human serum albumin). Control rats received this solution only (n = 11). VIP infusions resulted in a dose-dependent increase in plasma OT which was significantly greater than the slight rise observed in the controls. The difference from controls was significant at infusion rates of 3 pmol/min/kg and more. Plasma AVP, on the other hand, did not rise in response to VIP infusions until the infusion rate was increased to 300 and 3000 pmol/min/kg. At these infusion rates, the increments in AVP were much smaller than those of OT, the levels during the highest infusion rates rising to 8.6 +/- 2.8 and 27.2 +/- 4.8 microU/ml, respectively (log normal means). The preferential release of OT in response to exogenous VIP in rats differs from the response in cats where intracarotid administration of VIP resulted in the release of proportionately more AVP than OT. Immunoreactive VIP is found in the hypothalamo-neurohypophyseal system of rats in close proximity of some of the magnocellular neurons as well as within the nerve terminals. This, together with our data, suggests that endogenous VIP may participate in the release mechanism for OT in rats.
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PMID:Preferential release of oxytocin in response to vasoactive intestinal polypeptide in rats. 379 18

Using an aqueous extraction followed by ultrafiltration through Amicon Diaflo membranes, two ovine pineal fractions were obtained, which contain immunoreactive neurophysin. The presence of neurophysin was monitored by radioimmunoassay, employing an antiserum raised against pituitary bovine neurophysin and selected because it reacts with neurophysins of many other mammals. From 50 g of wet ovine pineal glands 552 micrograms of immunoreactive neurophysins were obtained. About 5% of these immunoreactive neurophysins are eluted from three different Sephadex columns with an elution volume corresponding to Mr above 10,000 between bovine serum albumin and pituitary neurophysin. The remaining 95% of ovine immunoreactive pineal neurophysin (Mr 10,000) shares immunological and physico-chemical properties with highly purified bovine pituitary neurophysin used as a reference. From the results of gel filtration and affinity chromatography on LVP-Sepharose it was concluded that ovine pineal gland may contain a neurophysin precursor molecule in addition to the neurophysin Mr 10,000.
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PMID:Presence of immunoreactive neurophysins of a higher molecular weight in addition to the 10.000 form in the ovine pineal gland. 403 11

1. Measurements have been made of the interaction of cytochrome c, bovine serum albumin and synthetic oxytocin with low-pressure (2dyn/cm) monolayers of stearic acid, phosphatidylcholine and phosphatidylethanolamine. 2. [(14)C]Carboxymethylation of the cytochrome c and albumin followed by surface-radioactivity determinations have shown that only a proportion of the protein added to the subphase is bound to the monolayers and that initially the degree of binding is dependent on the protein concentration. The binding is irreversible in the sense that the adsorbed protein cannot be removed by transferring the film containing the interacted protein to a fresh subphase containing no protein. 3. Three successive types of interaction can usually be recognized. (a) Initially, whole molecules of protein penetrate the lipid film and occupy the same area as those of the protein spread at the air/water interface. (b) Above certain film pressures a part of each protein molecule, probably hydrophobic side chains, penetrates the film. The change in surface pressure per unit of bound protein is much smaller than in (a). (c) At higher film pressures, adsorption without penetration occurs. With cytochrome c this is initially dependent on a favourable electrostatic interaction.
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PMID:An analysis of the interaction of protein with lipid monolayers at the air-water interface. 546 19

Synthetic bovine parathyroid hormone containing the 1-34 NH2 terminal amino acids [bPTH-(1-34)] is capable of inhibiting stimulated uterine contraction. The purpose of the present investigation is to determine whether the inhibitory action of bPTH-(1-34) is a direct action of the hormone fragment. The effect of different synthetic preparations of bPTH-(1-34), salmon calcitonin, corticotropin-inhibiting peptide and bovine serum albumin on oxytocin-stimulated uterine contraction was determined. In addition, the effects of atropine, propranolol, phentolamine, pyrilamine, cimetidine and the prostaglandin synthetase inhibitor indomethacin on the inhibitory action of bPTH-(1-34) on uterine contraction was determined. Both synthetic preparations of bPTH-(1-34) inhibited oxytocin-initiated contractions similarly. Salmon calcitonin, corticotropin-inhibiting peptide, and bovine serum albumin did not alter oxytocin-stimulated uterine contractions. The salmon calcitonin also did not alter the ability of bPTH-(1-34) to exert its inhibitory effect on uterine contraction. Cholinergic, alpha and beta adrenergic, histaminergic (H1 and H2) and prostaglandin synthetase inhibitors did not alter the action of bPTH-(1-34). These results suggest that the action of bPTH-(1-34) is 1) not due to the presence of a contaminant in the synthetic hormone preparation and 2) that the effect could be due to a direct action effect of the hormone fragment on uterine tissue.
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PMID:Direct effect of parathyroid hormone on rat uterine contraction. 608 71

Myoepithelial and secretory cells from the mammary gland of the lactating rat have been isolated, purified, and characterized. Mammary tissue was dissociated with collagenase into basket-like networks of myoepithelial cells and single secretory cells. Because of their larger size, the myoepithelial cell networks could be separated from other mammary and blood cells by differential centrifugation. Isolated secretory cells were purified by isopycnic centrifugation in 25% bovine serum albumin. The purified myoepithelial and secretory cells were viable, as shown by the incorporation of 32P into distinct macromolecules that were separable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both myoepithelial and secretory cells retained their characteristic morphology after isolation and purification, as shown by light, transmission, and scanning electron microscopies. The isolated myoepithelial cells were unique and, thus, distinguishable from other mammary cells in a number of respects; they 1) contracted in response to the addition of oxytocin, 2) bound [3H]oxytocin specifically, 3) accounted for the content of alkaline phosphatase and [Na+ + K+]ATPase in mammary tissue, and 4) reacted specifically with antiserum prepared against purified myoepithelial cells. The purified secretory cells were unique in possessing glucose-6-phosphate dehydrogenase activity. The different cell markers not only gave independent estimates of the purity of the cell fractions, but they also may be helpful in identifying mammary cells in stages of differentiation and neoplastic transformation.
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PMID:Purification and characterization of mammary myoepithelial and secretory cells from the lactating rat. 624 56

A sensitive and specific radioimmunoassay (RIA) for arginine vasopressin (AVP) has been developed and validated. Synthetic AVP was coupled to bovine serum albumin (BSA) with glutaraldehyde. Antisera against AVP were raised in three rabbits immunized with AVP-BSA complex. After 6 months, at the 16th injection, one of the antisera had a titer high enough to be utilizable for RIA at a final dilution of 1:400,000. The labeling of AVP with 125I Na was performed with the modified chloramine T method, and the purification of iodinated AVP was done with gel filtration chromatography on a Sephadex G-25 fine column (1 X 20 cm) with an elution buffer of 0.01 M acetic acid containing 0.1% BSA. Radioactivities from the Sephadex G-25 were eluted in three peaks. 125I-AVP, which was reactive to the antiserum, was contained in the third peak, and 125I-AVP in the fractions on the down slope of the peak was used for the radioligand in the amount of 1000 cpm. The specific activity of purified 125I-AVP was about 400 muCi/microgram. Diluted antiserum and samples, unlabeled AVP or related peptides were preincubated at 4 degrees C for 24 hr, and then 125I-AVP was added to the mixture and incubated for a further 72 hr. Separation of B and F was done with polyethyleneglycol. The minimal detection limit of AVP, which was 95% of the confidence limit of the mean value of B0, was 0.4 pg/tube. The cross-reactivities with lysine vasopressin, arginine vasotocin, DDAVP and oxytocin were 0.1%, 30%, 1% and 0%, respectively. AVP in plasma was extracted with cold acetone and petroleum ether. The recoveries of synthetic AVP from plasma which was added (2-16 pg) were more than 94%. The intra and inter-assay coefficients of variation determined by plasma of AVP concentration of about 4.8 pg/ml were 8.7% and 11.3%, respectively. The RIA detected AVP of concentration as low as 1 pg/ml following the extraction procedure. AVP immunoreactivity was detected without extraction in urine, and the lyophilized cerebrospinal fluid and acid extract of tissues of the central nervous system, and the reactivities in these samples were demonstrated to be immunologically identical to that of synthetic AVP when diluted serially. The changes of plasma and urinary AVP concentration on water intake, water deprivation and smoking in humans were clearly demonstrated.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[A sensitive and specific radioimmunoassay for arginine vasopressin and its validation]. 647 76

A highly sensitive and specific radioimmunoassay for LRF was applied to the measurement of endogenous LRF in various hypothalamic extracts. Specific antiserum was obtained by injecting LRF conjugated to human serum albumin with glutaraldehyde. Thyrotropin-releasing hormone, lysine vasopressin, oxytocin, noradrenaline, LH, FSH and cortical extracts did not appear to affect the assay, and the maximum cross-reaction observed with the LRF analogs tested was 8.5 p. 100 with LRF 2-10. The best detection limit (0.4 pg/tube) was usually obtained when the labelled LRF had been purified by polyacrylamide gel electrophoresis. Within and between-assay coefficients of variation were 8.0 and 12.6 p. 100, respectively (from B/Bo = 20 to 80 p. 100). Synthetic LRF administered to rams by intravenous injection was readily detectable in the peripheral plasma. However, the direct measurement of plasma endogenous LRF may give misleading results due to non-specific interference by plasma factors. No endogenous LRF could be detected in plasma methanol or acetone extracts obtained from rats and rams in various physiological conditions. The inhibition curves parallel to the synthetic LRF curve were obtained by diluting the crude hypothalamic extracts of rams and rats, and a good correlation (r = 0.997) with the Ramirez-McCann bioassay resulted, indicating that using radioimmunoassay to determine hypothalamic LRF content may be fruitful in studying hypothalamo-pituitary gonad interactions. The LRF content of rat and ovine hypothalami ranged from 2-8 to 20-80 ng of LRF, respectively.
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PMID:Reassessment of LRF radioimmunoassay in the plasma and hypothalamic extracts of rats and rams. 676 Feb 82

The distribution of gonadotropin-releasing hormone (GnRH) was studied in the brain and infundibulum (INF) or median eminence of sheep utilizing a peroxidase-antiperoxidase immunohistochemical method. This procedure utilized a specific antiserum generated against GnRH conjugated to bovine serum albumin. In the rostral INF, the greatest concentration of GnRH positive axons was found in the medial region, mostly in the external layer dorsal to the hypophysial portal plexus. In the intermediate portion of the INF, the hormone was mainly observed in the external layer at the more dorsolateral areas ventral to the tuberoinfundibular sulcus. GnRH was generally located medially in the caudal portion of the INF and dorsomedially in the rostral infundibular stalk. Substantial amounts of reaction product were also noted in the internal layer throughout the entire rostrocaudal extent of the INF. The hormone was localized in axons throughout the brain from the septal and medial preoptic areas to the mammillary bodies. GnRH-positive perikarya were scattered in various regions of the infundibular (arcuate) and for the first time in the ventromedial nuclei of sheep hypothalamus. Preabsorption of the specific antiserum with synthetic GnRH abolished staining in both axons and perikarya, whereas preabsorption with thyrotropin-releasing hormone, oxytocin, arginine-vasopressin, and adrenocorticotrophic hormone did not affect staining intensity.
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PMID:Immunohistochemical localization of gonadotropin-releasing hormone (GnRH) in the brain and infundibulum of the sheep. 701 81


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