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 isolated rat hindquarter preparation perfused at constant flow was used to determine resistance and capacitance responses from pressure and weight recordings. In response to noradrenaline at low concentrations, the capacitance effect was greater than the relative increase in total vascular resistance. 8-L-Arginine vasopressin showed capacitance responses only when the resistance vessel constriction was pronounced. Oxytocin and two synthetic analogues, 2-phenylalanine-8-ornithine vasopressin (Phe-Orn-VP) and 2-phenylalanine-8-ornithine oxytocin, showed varying potency for resistance vessel constriction but hardly any capacitance responses. However, when Phe-Orn-VP induced a small increase in total vascular resistance, a marked increase in post-capillary resistance was observed. The results are discussed in relation to a study in which the effects of vasopressin analogues were studied with intravital microscopy (Altura 1973).
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PMID:Effects of noradrenaline and vasopressin analogues on resistance and capacitance vessels in the rat hindquarter preparation. 235 60

The ligamentum infundibulo-cornuale (LIC) in the pig runs along the anterolateral side of the tubal isthmus, connecting the uterotubal junction and the edge of the infundibulum and has a comparatively well-developed muscular component running under the mesothelium. The well-vascularized smooth muscle cells held close cell-to-cell contacts and received innervation by adrenergic and cholinergic-like nerve terminals. Isolated LIC preparations, collected during oestrus showed a rhythmic spontaneous motility in vitro, the frequency and the relative amplitude of the contractions being highest during the preovulatory period. In vitro, noradrenaline and adrenaline elicited contractile (alpha) and relaxatory (beta) responses, while isoprenaline induced only beta-responses, as demonstrated by pretreatment with selective blockers. Oxytocin, PGF2 alpha and PGE2 always increased the muscular activity of the LIC. Indomethacin inhibited, in a concentration-dependent and reversible manner, the spontaneous motility of the porcine LIC, which could be fully restored by PGF2 alpha, indicating an endogenous local synthesis of prostaglandins in the tissue. The present results suggest that, in the pig, the LIC consists of a well-arranged, richly innervated bulk of smooth muscle which shows rhythmic spontaneous activity at the time of ovulation that could assist ova pick-up.
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PMID:The ligamentum infundibulo-cornuale in the pig: morphological and physiological studies of the smooth muscle component. 236 2

The direct action of biologically active substances on the smooth muscle cells tone was studied in isolated segments of the cow diencephalic arteries. The serotonin, histamine, vasopressin, potassium ions were found to induce a dose-dependent increase of the smooth muscles tone. Weak responses to oxytocin and noradrenaline were revealed.
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PMID:[Effect of various biologically active substances on the tonus of smooth muscle cells of the arteries of the diencephalon]. 242 95

Effects of oxytocin (OT) on the adrenal chromaffin tissue of male rats were examined by coupled morphometric and biochemical techniques. Synthetic OT was administered in doses of 0.14 and 0.25 IU/100 g/d during 7 or 10 consecutive days and the effects were followed 1, 24, 72 and 168 hours after the last injection. The function and structure of chromaffin cells were affected by the higher dose of OT only. They caused divergent responses on their amine contents. Adrenaline, noradrenaline and dopamine contents were increased, while serotonin content was decreased. These changes were different in duration and time of incidence. Stereological analysis showed an enhanced number of chromaffin cells and an increase in their total volume. The parallelism between the changes in chromaffin cell number and the catecholamine content strongly suggests a mitogenic effect of the applied OT.
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PMID:The response of rat adrenal medulla to oxytocin. 248 21

The substances stimulating the release of immunoreactive corticotropin-releasing factor from cultured human placental cells were investigated. Monolayer primary cultures of trophoblast cells from pregnant women at term were used. The immunoreactive corticotropin-releasing factor released in the culture medium eluted from high-performance liquid chromatography with the same retention time as human corticotropin-releasing factor. Norepinephrine and acetylcholine increased immunoreactive corticotropin-releasing factor release into the culture medium in a dose-related manner. Epinephrine was partially active, whereas dopamine and serotonin did not induce significant changes of immunoreactive corticotropin-releasing factor release from placental cultures. Angiotensin II, interleukin-1, oxytocin, and arginine-vasopressin also increased placental immunoreactive corticotropin-releasing factor release in a dose-related manner, whereas other peptides (vasoactive intestinal peptide, substance P, somatostatin, atrial natriuretic factor, interleukin-2) were ineffective. These results showed that several neurotransmitters and peptides stimulate the release of immunoreactive corticotropin-releasing factor from placental cells, suggesting their possible involvement in the physiologic regulation of placental immunoreactive corticotropin-releasing factor release during pregnancy and parturition.
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PMID:Neurotransmitters and peptides modulate the release of immunoreactive corticotropin-releasing factor from cultured human placental cells. 256 97

A review of current advances in anatomy, physiology and pharmacology of vasoactive intestinal polypeptide (VIP) is presented. VIP is a basic 28-aminoacid peptide of molecular weight 3300. Nerves immunoreactive to VIP are in the heart, lung, digestive and genitourinary tract, eye, skin, ovaries and thyroid gland. In the central nervous system VIP-ergic neurons are found primarily in telencephalic areas. Here, VIP provokes the excitation, vasodilatation and together with noradrenaline participates in the regulation of cortical energy metabolism. VIP-ergic neurons are mainly present in afferent pathways of the spinal cord with higher density in the sacral segments. Anatomic distribution of VIP-ergic neurons suggests involvement in pain transmission and integration of the sacral autonomic reflex pathways. The biologic effects of VIP in periphery are the vasodilatation, relaxation of smooth muscle and influence on exocrine glands secretion. In the endocrine system VIP stimulates the secretion of different hormones (prolaction, growth hormone, oxytocin, vasopressin, ovarial and thyroid hormones). VIP-ergic innervation is changed in some organs during the diseases of those organs. Practical exploatation of this knowledge is limited at present because effective, non-polypeptide agonists and antagonists are not available yet.
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PMID:[Vasoactive intestinal polypeptide: a potential neurotransmitter]. 257 79

Several extracts of Santolina chamaecyparissus ssp. squarrosa antagonized in a concentration-dependent way the contractions of rat duodenum, guinea-pig ileum, rat vas deferens and rat uterus as induced by acetylcholine, histamine, noradrenaline, oxytocin and serotonin. Polar extracts were less active than apolar extracts, and it was necessary to assay the former at higher concentrations. Only the lyophilized aqueous extract produced a slight hypotensive effect when given intravenously at 150 mg/kg to urethananesthetized rats.
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PMID:Inhibitory effects of Santolina chamaecyparissus extracts against spasmogen agonists. 261 13

The presence of neurohypophyseal nonapeptides in the adrenal gland of nonmammalian vertebrates and the possible action of these regulatory peptides on corticosteroid secretion have never been investigated. We have applied the indirect immunofluorescence technique to examine whether vasotocin (AVT) and/or mesotocin (MT) are located in frog adrenal (interrenal) tissue. Using antisera against AVT and tyrosine hydroxylase, we found that all chromaffin cells contain an AVT-like peptide. Labeling of consecutive sections with phenylethanolamine-N-methyltransferase or AVT antibodies showed that both noradrenaline- and adrenaline-storing cells contain AVT-like immunoreactivity. In contrast no labeling of frog adrenal slices was observed using a MT antiserum. At the ultrastructural level, the immunogold technique revealed that the AVT-immunoreactive peptide is sequestered in chromaffin granules with varying electron densities. Filtration of frog adrenal tissue extracts on Sep-Pak C-18 cartridges showed that the elution profile of the AVT-like peptide was similar to that of synthetic AVT. The apparent concentration of AVT in the adrenal was 2.7 ng/g tissue. Since chromaffin cells represent approximately one third of all interrenal cells, the actual concentration of AVT in chromaffin tissue was about 8 ng/g tissue. The role of AVT in the regulation of frog adrenal steroidogenesis was studied in vitro using perifused frog interrenal slices. Graded doses of AVT (10(-10)-10(-7) M) induced a dose-dependent stimulation of both corticosterone and aldosterone secretion. The other neurohypophyseal peptides (vasopressin, oxytocin, and MT) were also able to enhance corticosteroid secretion, but AVT was by far the most potent stimulator of steroidogenesis. Prolonged administration (4 h) of AVT induced a rapid increase in corticosterone and aldosterone output, followed by a gradual decline of corticosteroid secretion. These results show that an AVT-like peptide is stored in chromaffin granules of frog adrenal gland. Our data also indicate that synthetic AVT is a potent stimulator of corticosteroid secretion by frog interrenal cells. Since in amphibians adrenocortical and chromaffin cells are intimately intermingled, these results suggest that AVT produced by chromaffin cells may regulate corticosteroid release locally, through a cell to cell mode of communication.
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PMID:Identification of vasotocin-like immunoreactivity in chromaffin cells of the frog adrenal gland: effect of vasotocin on corticosteroid secretion. 267 89

This study was designed to examine the effects of psychological stress and oxytocin treatment (5.8 or 11.6 IU/kg) on noradrenaline, dopamine and serotonin levels in the hypothalamus, hippocampus and brainstem. Results indicated that repeated exposure to the novelty stressor resulted in amine levels which did not significantly differ from those of control levels. In contrast, oxytocin treatment produced a significant elevation in serotonin levels in each of the three brain regions examined, while the effects for dopamine were confined to the hypothalamus. Furthermore, when oxytocin was administered immediately prior to unpredictable exposure to the novelty stressor, a significant increase in levels of noradrenaline in the hypothalamus and serotonin in the hippocampus and brainstem were observed. These results suggest that oxytocin may play an important role in modulating monoaminergic activity which is also apparent when the animal is exposed to a psychological stressor.
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PMID:Influence of exogenously administered oxytocin on central noradrenaline, dopamine and serotonin levels following psychological stress in nulliparous female rats (Rattus norvegicus). 274 63

The contractile responses to various endogenous vasoactive agents were investigated in isolated human uteroplacental arteries from normotensive (NT) patients and patients with pre-eclampsia (PE) undergoing caesarian section. Tissue samples were obtained from the uterine incision and from macroscopically normal cotyledons. Vascular ring preparations of intramyometrial and stem villous arteries (length 1.0-1.3 mm, outer diameter 400-600 microns) were dissected and mounted in organ baths and isometric tension was recorded. Concentration-response relationships for vasopressin (VP), oxytocin (OX), angiotensin II (Ang II), noradrenaline (NA), 5-hydroxytryptamine (5-HT), prostaglandin F2 alpha (PGF2 alpha) and prostaglandin E2 (PGE2) were assessed. For each compound, the mean maximum contractile effect (Emax) and the drug concentration producing half-maximal response (EC50) were determined. In intramyometrial arteries from NT and PE patients, VP, Ang II, NA, 5-HT and PGF2 alpha induced contraction while OX and PGE2 produced weak or no responses. Preparations from PE patients showed higher Emax values, while no differences in EC50 were found between the two groups. In fetal stem villous arteries, Ang II, 5-HT, PGF2 alpha and PGE2 induced contractions, while VP, NA and OX produced weak responses. No differences in Emax or EC50 values were found between the fetal vessels of PE and NT patients. No qualitative differences were demonstrated in response to the agents tested between the vessels (fetal and maternal) from NT women at term and PE patients. However, the results may reflect quantitative differences, suggesting increased contractility of maternal uteroplacental arteries from women with PE.
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PMID:Effect of endogenous vasoconstrictors on maternal intramyometrial and fetal stem villous arteries in pre-eclampsia. 276 Apr 57


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