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 method for the isolation and localization of proteins and peptides from histological sections of rat and human brain by immunoblotting is described. For validation, the well-characterized protein neurophysin was electrophoretically transferred from formaldehyde-fixed or fresh tissue sections onto a nitrocellulose membrane. Neurophysin on the nitrocellulose membrane was detected by a specific antibody reaction. The antibody against neurophysin was visualized either by using secondary antibodies, conjugated with peroxidase or by protein A gold, followed by enhancement with silver. With this simple and fast method, neurophysin (or other proteins and peptides) can be identified on nitrocellulose membranes in areas that correspond to anatomically defined regions. Since the procedure combines the advantages of precise regional localization of polypeptides with the specificity of antibody-antigen reactions, the method may prove useful for rapid screening of the distribution of peptides or proteins in (brain) tissue.
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PMID:Direct immunoblotting from histological sections of brain onto nitrocellulose: evaluation with the protein neurophysin. 228 62

Previously (Van Driessche et al. 1987) we showed that small inward (mucosa towards serosa) oriented short-circuit currents (Isc) were recorded through the toad urinary bladder when the mucosal side was exposed to Ca2+ free solutions containing K+, Na+ (+ amiloride), Cs+ or Rb+ as main cation. This current component is inhibitable by micromolar concentrations of mucosal La3+ and divalent cations (Ca2+, Cd2+) and is considerably elevated by oxytocin (0.1 U/ml). The present study demonstrates that the addition of 50 nmol/l Ag+ to the mucosal medium during oxytocin treatment caused an additional large increase of the La3+-sensitive Isc component. The power density spectrum of the fluctuation in current contained a Lorentzian component which was enhanced by oxytocin treatment. The Lorentzian component disappeared as a consequence of the administration of mucosal Ag+. In experiments with Ca2+, Ba2+ or Mg2+ as principal mucosal cation, the La3+-sensitive Isc component was negligible under control conditions and during oxytocin treatment. Mucosal Ag+ (40 nmol/l) elicited a large inward oriented current which was blockable by the calcium channel blockers, La3+ and Cd2+. Also the organic calcium entry blockers, nicardipine and verapamil (10 mumol/l) depressed the inward current considerably. Noise analysis of the currents carried by divalent cations showed a La3+-sensitive noise component. Oxytocin-Ag+ activated currents could not be recorded in the absence of the divalent cations or small inorganic cations, e.g. with solutions which contained N-methyl D-glucamine (NMDG) as main mucosal cation.
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PMID:Ca2+ channels in the apical membrane of the toad urinary bladder. 244 54

1. Na+ as well as Li+ move across the apical membrane through amiloride-sensitive ionic channels. 2. K+ movements across the apical membrane occur through Ba2+- and Cs+-sensitive channels which do not allow the passage of Na+ or Li+. 3. A third pathway in the apical membrane is permeable for Na+, K+, Cs+, Rb+, NH+4 and Ti+. The currents carried by these monovalent cations are blocked by Ca2+ and divalent cations as well as La3+. 4. In the urinary bladder, the Ca2+-sensitive currents are stimulated by oxytocin, activators of cytosolic cAMP and cAMP analogues. Also the oxytocin activated currents are blocked by divalent cations and La3+. 5. Nanomolar concentrations of mucosal Ag+ activate the third channel and open the pathway for movements of Ca2+, Ba2+ and Mg2+, which are known to permeate through Ca2+ channels in excitable tissues.
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PMID:Cation-selective channels in amphibian epithelia: electrophysiological properties and activation. 246 Feb 85

Some features of oxytocin stimulation of a cation-selective channel of the apical membrane of amphibian tight epithelia were examined in an attempt to understand the channel's role in the regulation of epithelial transport. We first examined the ability of the channel to pass alkaline-earth cations. We found that oxytocin can stimulate the movement of alkaline-earth ions through the channel. This stimulation became greatly enhanced by treatment with Ag+. The stimulation of alkaline-earth movements is discussed together with recently reported experiments which suggest that the channel may be involved in K+ secretion. In addition we carried out comparative studies of the effects of oxytocin on the channel in a variety of epithelia obtained from different amphibians to examine whether the stimulation of ionic currents through the channel and the enhancement of hydrosmotic permeability caused by the hormone are linked. The results of our experiments showed that oxytocin activates the channel in the urinary bladders of Bufo marinus, and Rana catesbeiana as well as in the skin of B. marinus. It is well known that in all these tissues the hormone increases water permeability of the apical membrane. On the other hand, in skins of Rana catesbeiana, Rana pipiens, and Rana temporaria, where oxytocin does not have a hydrosmotic effect, the hormone did not increase the currents through the cation-selective channel.
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PMID:Role of an apical cation-selective channel in function of tight epithelia. 247 42

We investigated whether a sustained increase in oxytocin secretion, with or without enhanced electrical activity of the cell-bodies of oxytocin neurones, leads to a rapid increase in oxytocin mRNA content in these neurones. To stimulate oxytocin release, naloxone (2.5 mg/kg i.v. twice, 30 min apart) was given to urethane-anaesthetized female rats after intracerebroventricular (i.c.v.) morphine or vehicle infusion for 5 days; in the latter, naloxone acts on the neurohypophysis to increase oxytocin release without affecting the electrical activity of oxytocin neurone cell-bodies, but in the former, naloxone acts both on the neucohypophysis and on the cell-bodies to excite them electrically. Oxytocin content in peripheral plasma was measured intermittently by radioimmunoassay for 4 h after i.v. naloxone or vehicle, then the brain was removed and cryostat sections were cut through the supraoptic nucleus (SON). Oxytocin mRNA content in individual neurones (25-50 per rat) was measured semiquantitatively by in situ hybridisation histochemistry, using a tritiated synthetic cDNA 25-mer oligonucleotide probe, autoradiographical visualisation, and computer-assisted image-analysis to measure silver grain density. Nalaxone increased oxytocin content in plasma 7-fold for at least 40 min in i.c.v. vehicle-infused rats, and 40-fold for at least 40 min in i.c.v. morphine-infused rats. Naloxone had no significant effect on the oxytocin mRNA content in labelled cells in the SON, and no effect on the proportion of labelled cells, in either the i.c.v. morphine- or i.c.v. vehicle-infused rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Does acute, intense stimulation of oxytocin neurones in the supraoptic nucleus increase their content of oxytocin mRNA? 274 58

In order to examine the morphological substrates for neuronal connections between cells of the hypothalamic suprachiasmatic nucleus (SCN) that contain immunoreactivity for different neurotransmitters, a double ultrastructural immunocytochemical analysis was used. For double immunostaining, the first neuroactive substance antigen was labeled with gold-substituted silver-intensified peroxidase (GSSP), which results in a granular gold deposit of high electron and light opacity. The second antigen was labeled with peroxidase and a diaminobenzidine chromagen. The GSSP reaction product greatly increased the visibility of immunoreactive structures, with both light and electron microscopy. Intensification with the GSSP method worked at all depths of thick tissue sections as determined with analysis of immunostained sections cut perpendicular to their flat surface, and with analysis of thick 80-micron sections of brain tissue into which horseradish peroxidase (HRP) has been microinjected. On a nitrocellulose dot-blot comparison of different substrates for HRP, the GSSP intensification compared favorably with tetramethylbenzidine, but unlike tetramethylbenzidine, the GSSP was stable in a wide range of buffers. In addition to diaminobenzidine, the GSSP reaction was used to intensify and stabilize both the Hanker-Yates reagent and tetramethylbenzidine on the nitrocellulose model system. Through the use of the GSSP reaction, five new synaptic relationships in the suprachiasmatic nucleus were revealed. By increasing the sensitivity of the peroxidase method by silver-gold intensification, immunoreaction product could be found in dendrites at a greater distance from the perikaryon than in nonintensified material. Because of this greater sensitivity, the neuroactive substance contained in the cell of origin of a dendrite could sometimes be identified. Boutons immunoreactive for vasopressin-associated neurophysin were found to make synaptic contact with postsynaptic dendrites that also contained vasopressin-neurophysin immunoreactivity. Similarly, boutons containing gastrin-releasing peptide immunoreactivity made synaptic contact with cells also exhibiting gastrin-releasing peptide immunoreactivity. Neurons stained with GSSP reaction product could be easily discriminated from those containing only HRP-precipitated diaminobenzidine, allowing the simultaneous use of these two markers in the same 30-micron tissue section and subsequently in ultrathin sections for electron microscopy.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Synaptic relationships between neurons containing vasopressin, gastrin-releasing peptide, vasoactive intestinal polypeptide, and glutamate decarboxylase immunoreactivity in the suprachiasmatic nucleus: dual ultrastructural immunocytochemistry with gold-substituted silver peroxidase. 287 14

In situ hybridization (ISH) using a 25 mer tritiated oligonucleotide probe has been performed to study at the electron microscopic level the subcellular localization of the oxytocin mRNA in the rat hypothalamic magnocellular neurons. After high resolution radioautography, silver grains appeared to be localized over the cytoplasm of some magnocellular neurons of the supra-optic nucleus and frequently overlapped the ergastoplasmic "cisternae" of the Nissl bodies. These results demonstrate the possible application of ISH at a subcellular level using high resolution radioautography and a tritiated probe.
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PMID:[Ultrastructural localization of mRNA coding for oxytocin by in situ hybridization. Study by high resolution autoradiography using a tritiated oligonucleotide probe]. 314 10

Binding of the muscarinic cholinergic receptor probe [3H]quinuclidinylbenzilate ([3H]QNB) and the putative nicotinic receptor probe [125I]alpha-bungarotoxin ([125I]alpha BTX) to vasopressin (VP) and oxytocin (OT) neuroendocrine cells was investigated with a combination of quantitative receptor binding, autoradiography and immunocytochemistry. A single high-affinity site was labelled by [3H]QNB in the hypothalamus and pituitary (KD = 0.76-1.44 X 10(-10) M) with a mean hypothalamic density of 213 fmol/mg protein compared with only 56 fmol/mg protein in the pituitary. Analysis of autoradiographic silver grains from [3H]QNB binding revealed a relative absence of binding associated with magnocellular VP and OT cell groups in the hypothalamus. The median eminence and neural lobe of the pituitary contained low levels of [3H] QNB binding, which, however, were the highest within the hypothalamo-neurohypophysial system. The ligand [125I]alpha BTX binds with both a high and low affinity to sites within the hypothalamus and pituitary (high-affinity KD = 0.77-1.03 X 10(-10) M). In the hypothalamus the density of high-affinity binding sites (25 fmol/mg protein) is approximately 2.5 times greater than in the pituitary. In contrast to [3H]QNB, high-affinity binding of [125I]alpha BTX was found to be highly concentrated within the supraoptic nucleus, nucleus circularis, and the magnocellular areas of the paraventricular nucleus. Autoradiographic silver grains were distributed over both VP and OT immunoreactive neurons and processes. Binding within the neural lobe was very low. These data suggest that the cholinergic regulation of VP and OT release may occur via nicotinic cholinergic receptors at the level of the magnocellular cell bodies and predominantly via muscarinic cholinergic receptors within the neural lobe.
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PMID:Differential distribution of muscarinic cholinergic and putative nicotinic cholinergic receptors within the hypothalamo-neurohypophysial system of the rat. 382 79

Using radioautography and immunocytochemistry, we investigated differences in 3H-cytidine incorporation into RNA in vasopressin or neurophysin-positive neurons in the rat hypothalamus following adrenalectomy. Control animals and those that had been bilaterally adrenalectomized for 2 weeks received 0.3 mCi 3H-cytidine subcutaneously and were decapitated 1 h following injection. Brains were prepared for combined radioautography and immunocytochemistry. Incorporation was estimated by counting silver grains over immunoreactive neurons. The neurons of the paraventricular nucleus (PVN) showed a consistent and significant increase in the amount of incorporation of label 2 weeks after bilateral adrenalectomy. There was no change in incorporation in neurons of either the supraoptic or suprachiasmatic nuclei. These findings suggest that the vasopressin PVN neurons, some of which project to the zona externa of the median eminence, are activated under conditions of adrenalectomy.
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PMID:Effects of adrenalectomy on the incorporation of 3H-cytidine in neurophysin and vasopressin-containing neurons of the rat hypothalamus. 615 41

The magnocellular and paravocellular regions of the rat hypothalamic paraventricular nucleus (PVN) were examined in several hundred brains. Converging qualitative and quantitative anatomical methods, including Golgi impregnations, Nissl stains, silver stains, and immunocytochemistry were used to study the intrinsic organization of the PVN with light, scanning, and transmission electron microscopy. A computer-assisted quantitative analysis of dendritic branching patterns was used to examine total dendritic length, center of mass, orientation of dendritic tree, and several other parameters of dendritic organization and revealed statistically significant differences between cells in the lateral and posterolateral magnocellular and medial parvocellular areas of PVN. Electron microscopy, Golgi impregnation, and neurophysin immunohistochemistry showed that dendrites of posterolateral cells were generally oriented perpendicular to the third ventricle; dendrites of cells in the lateral PVN usually projected medially from the perikaryon. Cells in the medial zone of PVN had dendritic trees which often paralleled the third ventricle. Large numbers of axons entered and left PVN ventrally near the midline and laterally in the area of the posterolateral PVN; axons generally were oriented parallel to the mean major axis of dendritic trees in these areas. Ultrastructural examination of serial thin sections showed a peculiar astroglia multiple lamellar isolation of axodendritic synaptic contacts. Intrinsic axons commonly arose from parvocellular but not from magnocellular neurons and contacted dendrites of both medial parvocellular and more lateral magnocellular neurons. Synapses were found on shafts and spines of dendrites, on perikarya and somatic appendages, and invaginated into the soma. Both dendrites axons with large neurosecretory vesicles and immunostained with neurophysin antiserum were found postsynaptic to other axons. Presynaptic neurosecretory axons were not found within the PVN. A semiquantitative analysis of catecholamine axons identified with the glyoxylic acid method and fibers immunoreactive with ACTH and Substance P antisera indicated that the parvocellular region of PVN received ggreater innervation than the lateral magnocellular area; similarly, a reater density of stained fibers was found in the medial parvocellular PVN region with Golgi impregnations and silver stains. With a stereological analysis of 1-micrometer plastic sections, the parvocellular area had a significantly greater neuropil to cell volume ration, with cells accounting for 48 +/- 9% in the lateral magnocellular zone, but only for 26 +/- 7% in the parvocellular area. A quantitative analysis of vasculature from thin sections showed that the PVN had 3.3 times more blood vessels, and 3.6 times more lumen perimeter than a control area ventrolateral to PVN; an interesting finding here was that the medial parvocellular PVN had a high degree of vascularity, not significantly different from the lateral magnocellular zone...
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PMID:The magnocellular and parvocellular paraventricular nucleus of rat: intrinsic organization. 709 31


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