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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Synthetic oxytocin and [8-arginine]-vasopressin conjugated to bovine thyroglobulin were used to induce specific antibodies in rabbits. The specificity of the anti-oxytocin serum, and the suitability of the anti-[8-arginine]-vasopressin serum for the detection of [8-lysine]-vasopressin, was evaluated by immunofluorescent studies of the respective hormones bound to Sepharose 4B particles. Oxytocin and [8-lysine]-vasopressin were specifically localized in the paraventricular (PVN) and supraoptic (SON) nuclei of the pig hypothalamus using the immunoperoxidase staining technique. After an examination of serial transverse and sagittal sections stained for either of the hormones we observed that: 1. In the rostral SON, oxytocin and vasopressin containing neurons were uniformly distributed; 2. In the caudal SON, most of the neurons contained oxytocin, but there were still a few 'vasopressin' neurons; 3. In the rostral PVN, the two hormones were evenly spread in neurons close to the third ventricle; 4. In the caudal PVN, the oxytocin and vasopressin containing neurons were differentially distributed, with 'oxytocin' neurons adjacent to the third ventricle, and 'vasopressin' neurons lateral to these and concentrated in the dorso-caudal PVN. In the cells of the PVN, there was evidence that the distribution of oxytocin and vasopressin is similar to the distribution of porcine neurophysin-II and porcine neurophysin-I respectively. This similarity is consistent with the one hormone--one neurophysin concept in the pig.
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PMID:Immunocytochemical study of the hypothalamo-neurohypophysial system. III. Localization of oxytocin- and vasopressin-containing neurons in the pig hypothalamus. 32 54

A radioimmunoassay for oxytocin in cow plasma is described. Antisera were raised in rabbits against synthetic oxytocin coupled to bovine thyroglobulin. Iodinated oxytocin free of unlabelled oxytocin and most likely also free of diiodo-oxytocin was used as radioactive tracer. The tracer showed a high degree of purity, and was stable on storage. It could be used in the assay for 2--3 months. The assay showed very little cross-reactivity with vasopressin. Acetone was used for the extraction of oxytocin from plasma as well as from standards made of synthetic oxytocin in pooled cow plasma. Inhibition curves obtained with plasma collected from cows at parturition were parallel to those obtained with the oxytocin standard preparation. The mean recovery of oxytocin added to cow plasma was 106% (SD = 14). The within-assay coefficient of variation (CV) varied from 5.2 to 10.9%, and the between-assay CV was in the order of 13%. The assay sensitivity was 1 pg (0.5 uU) per tube, corresponding to 3 pg/ml plasma. Around the time of milking the plasma oxytocin profile showed a strong response to the preparation for milking, and a further effect releated to the attachment of the teat cups of the milking machine. Peak concentrations were in the range of 15--50 pg/ml. During parturition there was a peak of oxytocin (65 pg/ml) coinciding with the expulsion phas. After this peak levels decreased but remained measurably elevated until the expulsion of the placenta. The plasma disappearance curve for immunoreactive oxytocin after the infusion of 100 IU oxytocin over a period of 1 h showed two components with apparent half-lives of 7--7 and 25 min, respectively.
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PMID:Oxytocin determination by radioimmunoassay in cattle. I. Method and preliminary physiological data. 49 91

The present paper deals with the development of an immunofluorescence procedure that allows specific localization of vasopressin and oxytocin in the hypothalamo-neurohypophyseal system(hnx) of the rat. Antibodies against arginine vasopressin (AVP), lysine-vasopressin (LVP) and oxytocin were raised by injecting these hormones that were covalently bound to thyroglobulin into rabbits. The vasopressin-immunized rabbits showed periods of diabetes insipidus, while histoloty of the "hns revealed an intact neurosecretory system with signs of increased endogenous hormone synthesis in the supraoptic nucleus and increased release in the neuro-hypophysis of some rabbits. The daily water intake of the oxytocin-immunized rabbits was similar to that of control rabbits. The development of antibodies against vasopressin as measured in the immunofluorescence procedure showed a course that was quite different from the curve of the titer as determined by radioimmunoassay (RIA). Also the specificity of the antibodies used in the immunofluorescence procedure was found to be quite different from their specificity in a RIA system. Potency and specificity of the antibodies have to be studied therefore within the immunofluorescence procedure itself. Using freshly frozen acetone-postfixed hypotalami or pituitaries, no sharp localization of immunofluorescence could be obtained in the HNS. Therefore prefixation was performed. Both, the type and the duration of prefixation revealed quite different results regarding the immunofluorescence in the neurosecretory cell boides in the hypotalamus and of their endings in the neurohypophysis. The best immunofluorescence results were obtained using 6 hours glyoxal-prefixation for the hypothalamus and 24 hours formalin-prefixation for the pituitary. The cross-reaction of the antibodies for oxytocin or vasopressin was tested on synthetic hormones that were bound to CNBR-activated agarose beads and mounted on glass sides. All anti-plasmas showed cross-reaction on beads containing the heterologou- antigen. The plasmas were purified by incubation with beads containing the heterologous hormone until the cross-reacting component had been removed. Using purified antibodies, the distribution of oxytocin and vasopressin cells within the HNS was investigated. More oxytocin containing cells were localized in the rostral part and more vasopressin in the caudal part of both, the supraoptic (SON) and paraventricular nucleus (PVN). Comparable percentages of oxytocin and vasopressin containing cells were found in the SON and PVN. The absolute amount of oxytocin containing cells was 2.5 times more in the SON than in the PVN, which seems to contradict the "classical" view that the PVN predominantly or entirely synthetizes oxytocin. In addition, fluorescence was found using antobodies against vasopressin in the suprachiasmatic nucleus in Wistar rats and heterozygous Brattleboro rats, but not in this nucleus of homozygous Brattleboros.
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PMID:Immunofluorescence of vasopressin and oxytocin in the rat hypothalamo-neurohypophypopseal system. 110 Jul 84

An immunocytochemical investigation was carried out on round and spreading hemocytes of Planorbarius corneus by using 20 antisera to vertebrate bioactive peptides. The immunotests showed the presence of alpha 1-antichymotrypsin-bombesin-, calcitonin-, CCK-8 (INC)-, CCK-39-, gastrin-, glucagon-, Met-enkephalin-, neurotensin-, oxytocin-, somatostatin-, substance P-, VIP-, and vasopressin-immunoreactive molecules in the spreading hemocytes. The round hemocytes were only positive to anti-bombesin, anticalcitonin, anti-CCK-8 (INC), anti-CCK-39, anti-neurotensin, anti-oxytocin, anti-substance P and anti-vasopressin antibodies. No immunostaining was observed with anti-CCK-8 (Peninsula), anti-insulin, anti-prolactin, anti-thyroglobulin and anti-thyroxin (T4) antibodies. As probably in vertebrates, these bioactive peptides may modulate immuno cell function.
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PMID:Immunocytochemical evidence of vertebrate bioactive peptide-like molecules in the immuno cell types of the freshwater snail Planorbarius corneus (L.) (Gastropoda, Pulmonata). 169 11

To induce a good immune response to oxytocin (OT) we developed a two-step technique to conjugate OT to thyroglobulin (TG) using glutaraldehyde. We obtained 30 hybridomas recognizing OT-ovalbumin conjugates and 16 stable lines. Three monoclonal antibodies were selected for further characterization. One of them (O13) was found very specific for OT using three different techniques (enzyme-linked immunosorbent assay, radioimmunoassay and immunohistochemistry); it is directed to the C-terminal tripeptide. The other two probably recognize tyrosine containing epitope(s) also shared by vasopressin and other related nonapeptides.
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PMID:Monoclonal antibodies to oxytocin: production and characterization. 199 53

Antisera were raised in rabbits against Pro-Leu-Gly-NH2 (PLG)-bovine thyroglobulin conjugates. Specificity of the antisera towards oxytocin was evaluated by a radioimmunoassay as well as by immunohistochemical procedures on hypothalamic tissue and hormone bound to Sepharose beads. It was concluded that immunization with PLG can raise antisera that are specific to oxytocin.
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PMID:Immunochemical recognition of oxytocin by antiserum to L-prolyl-leucyl-glycine amide. 285 63

We describe a specific double-antibody radioimmunoassay for measuring arginine vasopressin (AVP) in human plasma. Antisera of high avidity were obtained from rabbits that had been injected with AVP coupled to bovine thyroglobulin. The antibody reacts with both the tripeptide tail and the pentapeptide ring of the molecule, thereby eliminating cross reaction with oxytocin. Synthetic AVP was labeled with 125I by a modification of the Chloramine-T technique. The specific activity of the labeled hormone was 29 MBq/micrograms of AVP, as estimated by self-displacement analysis. The assay involves Sep-Pak C18 extraction of acidified (pH 4) plasma. Recovery of [3H]AVP added to plasma averaged 86.6 (SD 6.1)% (n = 14). Dilution curves for plasma showed linearity of response with concentration. The overall sensitivity was 0.3 ng/L when 2-mL plasma samples were extracted. The intra-assay CV was 7.8% at 4.8 ng/L (n = 12) and the interassay CV was 12.3% (n = 16) and 6.3% (n = 14) at 2.7 and 4.1 ng/L concentrations, respectively.
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PMID:Development and evaluation of a radioimmunoassay for Arg8-vasopressin, after extraction with Sep-Pak C18. 298 81

This report presents characteristics of an antiserum raised in a rabbit immunized with synthetic mesotocin (MT) conjugated to bovine thyroglobulin. Cross-reactivity studies indicate that the antiserum (Kl-II) recognizes the carboxyl-terminal "tail" of MT and isotocin (IT). A homologous, disequilibrium radioimmunoassay (RIA) for MT has been developed that can detect less than 1 pg of peptide. Plasma was extracted with octadecasilyl-silica. Recovery of MT from plasma was correlated with the amount added and averaged 70%. Different volumes of plasma and posterior pituitary extract, when measured in the assay system, yielded inhibition curves that were parallel with standard MT. Immunoreactive MT and AVT of plasma and neural lobe coeluted with synthetic standards after gel filtration. The ED50 of a heterologous, sequential saturation RIA for IT was 17.4 pg, suggesting that the MT antiserum may be useful for measuring the oxytocin-like principle in bony fishes. Immunoreactive MT in plasma of cockerels increased and decreased with iv infusion of hypo- and hyperosmotic saline, respectively. The changes in plasma MT were inversely related to osmolality. Hyperosmotic saline infusion resulted in correlated increases in plasma AVT and osmolality. The data suggest that MT may be released by dilution and/or expansion of extracellular fluid in chickens.
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PMID:An antiserum that recognizes mesotocin and isotocin: development of a homologous radioimmunoassay for plasma mesotocin in chickens (Gallus domesticus). 377 Apr 49

Synthetic oxytocin (OT) conjugated to bovine thyroglobulin by the carbodiimide reaction was injected into rabbits to raise a high titre, specific OT antiserum which was then coupled to microcrystalline cellulose activated by cyanogen bromide. High affinity of the coupled antiserum was defined by Scatchard analysis, Keq = 7.1 X 10(11)1/mol. Cross-reactivity studies revealed little binding of antiserum to analogues of OT. Iodination was performed by the Chloramine T method, giving specific activity of 125I-OT, range 1.1 - 1.7 X 10(3) Ci/mmol. After incubation for 40 hours under disequilibrium conditions, specific and non-specific bindings were 10.6 +/- 2.7% and 0.2 +/- 0.1% (n=15), respectively. Displacement of 50% 125I-OT occurred with 2.9 pg OT/tube. Coefficients of variation of standard OT concentrations (0.03 - 16 pg/tube) were less than 5%. Limit of detection was 2 pg OT/ml plasma. Recovery of synthetic OT added to non-pregnant plasma was 81.8% (n=34) at 20 pg/ml and 97.4% (n=32) at 100 pg/ml. Two patients, 17 and 18 weeks post-partum, had increases in plasma OT from less than 2 pg/ml to 18.3 and 16.0 pg/ml after 6 and 4 minutes breast feeding infants, respectively. We conclude that this solid phase OT radioimmunoassay is quick, relatively sensitive and reliable, and does not require prior extraction of plasma samples.
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PMID:Solid phase radioimmunoassay for direct measurement of human plasma oxytocin. 390 Jan 38

The hypothalamic peptide MIF-1 (Pro-Leu-Gly-NH2) was coupled to thyroglobulin and injected into rabbits. The resulting antiserum reacted with the tetrapeptide Tyr-MIF-1 to a greater extent than with the tripeptide MIF-1, presumably because of a better conformation for antibody binding. By radioimmunoassay (RIA), immunoreactive MIF-1/Tyr-MIF-1-like material was found in the pineal gland of each of the 100 rats examined. The tendencies for slightly higher levels in pineals obtained from rats kept in constant darkness for two weeks, from rats in a normal light cycle decapitated at noon, or from rats which had been hypophysectomized were not statistically significant. Gel filtration of pineal extracts on a column of Sephadex G-10 revealed that by RIA one immunoreactive peak eluted near MIF-1 and oxytocin, and another peak near Tyr-MIF-1. The results suggest the presence in pineal tissue of an MIF-1-like material as well as a novel peptide containing Tyr-Pro-Leu-Gly-NH2 or a closely related structure for which oxytocin is unlikely to be the precursor.
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PMID:Radioimmunoassay of MIF-1/Tyr-MIF-1-like material in rat pineal. 611 Oct 86


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