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)

1. A technique for perfusion of skin has been used to investigate a possible neurochemical basis for the different patterns of sweating in domestic animals. Evaporative water loss was measured from excised trunk skin, ears or tails perfused with a nutrient Krebs solution, to which drugs were added as required. Perfused skin was observed to sweat in response to administration of sudorific drugs, and some features of the patterns of sweating were similar to those which could be induced by heating or by drugs in conscious animals. 2. In sheep and goat skin, injections of adrenaline, and to a lesser extent of noradrenaline, elicited brief sweat discharges but these were not sustained when the drugs were infused during 10-20 min. Injections of isoprenaline, carbachol, 5-HT, bradykinin, oxytocin and histamine were all ineffective. 3. Injections of adrenaline into cattle skin evoked longer-lasting sweat discharges, and infusions of adrenaline elicited continuous discharges. Injections of noradrenaline and sometimes of bradykinin caused only brief sweat discharges; other drugs were ineffective. 4. In horse and donkey skin, injections or infusions of noradrenaline, oxytocin and bradykinin elicited brief discharges of sweat. Infusions of isoprenaline caused a continuous and profuse outflow of sweat. Infusions of adrenaline also caused a continuous discharge which was usually biphasic in its onset. Other drugs were ineffective. 5. Assuming that the brief sweat discharges are due to myoepithelial contractions and the continuous discharges to sustained increases in secretion, equine sweat glands seem to have a alpha-adrenergically controlled myoepithelium and a beta-adrenergically controlled secretory mechanism. Sheep and goats may have a similar alpha-adrenergic control of the sweat gland myoepithelium but only a feeble sweat secretory mechanism. In cattle, an alpha-adrenergic mechanism appears to control sweat secretion, but the control of the myoepithelium is uncertain.
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PMID:Sweat gland function in isolated perfused skin. 117 53

The importance of sympathetic innervation changed significantly during sexual maturation and in the course of the oestrous cycle in females. Basal secretion of progesterone is partly dependent on constant beta-adrenergic stimulation since local infusion of propranolol (beta-blocker) into the ovary decreased progesterone secretion by 20-30% of pre-treatment value. Noradrenaline given into the abdominal aorta in the moderate doses affected very quickly and dramatically the secretory function of the corpus luteum during the luteal phase in cattle and also in other species. Thus short-lasting mobilization stress protects and even supports corpus luteum function. This effect is exerted through the stimulation of beta-adrenoceptors which then activates specific intracellular enzymes. Additionally noradrenaline acts upon vascular alpha-receptors and increase ovarian blood flow allowing utilization of serum-derived lipoprotein as a source of cholesterol for steroidogenesis. The highest amount of specific beta-receptors in luteal membranes was found in the newly-formed corpus luteum which does appear to require noradrenergic support especially at that stage of its development. The mechanism of noradrenaline influence upon luteal cells resulting concomitant progesterone and ovarian oxytocin secretion is, however, obscure. It is suggested that intracellular second messengers (cAMP, Ca2+) involved in noradrenaline action can simultaneously affect the secretion of both these hormones and this indicates some functional relationship between them. The presented results are focused mainly upon cattle due to the importance of this species among other domestic animals. Nevertheless for comparison data from other species are also quoted.
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PMID:Role of the noradrenergic system in the secretory function of the corpus luteum. 134 65

The vasoconstrictor effect of the peptides neuropeptide Y (NPY), endothelin (ENDO), vasopressin (VPR) and oxytocin (OXY) (10(-11)-10(-7) M) was compared in the isolated basilar (BAS) and mesenteric (MES) arteries of rat. The contractile activity of these peptides was compared to that of three nonpeptidergic constrictors: noradrenaline (NA), serotonin (5-hydroxytryptamine, 5-HT) and prostaglandin F2 alpha (PGF2 alpha) (10(-8)-10(-4) M). As regards EC50 values, PGF2 alpha was equally potent in both vessels studied, 5-HT was more potent in BAS and NA was without contractile effect in BAS. Pronounced regional differences were found for the peptides studied. BAS was more sensitive in EC50 values to the peptides in the order ENDO > or = VRP > OXY > NPY. In MES, OXY and NPY caused no and VPR caused weak contraction, whereas the effect of ENDO was pronounced, with a similar EC50 value as in BAS. In conclusion, marked regional differences were found in response to contractile agents in the vascular beds studied. Peptidergic constrictor mechanisms might be of large importance in the regulation of cerebral blood flow during physiological or pathophysiological conditions.
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PMID:Regional differences in the contractile activity of neuropeptide Y, endothelin, oxytocin and vasopressin: comparison with non-peptidergic constrictors. An in vitro study in the basilar and mesenteric arteries of the rat. 136 91

Experiments on isolated strips of the non-pregnant rabbit and rat uterus showed the ability of dopamine, noradrenaline, serotonin, acetylcholine, prostaglandin F2 alpha, oxytocin to increase the uterine strips contractile activity. On the other hand, GABA, GABAB receptors agonist phenibut and diazepam inhibit the stimulating effects of the above mentioned substances, thus showing the properties of physiological antagonists of these neuromediators, prostaglandin and oxytocin.
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PMID:[Action of GABA-positive preparations on uterus-stimulating effects of activating neuromediators, prostaglandin F2 alpha and oxytocin]. 139 97

The neurohypophyseal peptides arginine vasotocin, oxytocin and arginine vasopressin contracted guinea pig, rat, canine and human prostates with potencies and efficacies that were comparable to those of noradrenaline and methacholine. All three neuropeptides raised prostatic tone and elicited contractions at 10(-9) or 10(-8) M, with an order of efficacy: arginine vasotocin greater than oxytocin greater than arginine vasopressin. The findings suggest a physiological role for these peptides in prostatic smooth muscle contraction and possibly also in other aspects of male reproductive function.
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PMID:Contractile activity of vasotocin, oxytocin, and vasopressin on mammalian prostate. 139 15

1. The adrenergic neurone blocking agents, guanethidine and bretylium, have been tested for inhibitory activity against the actions of some relaxant drugs (BRL 38227, noradrenaline, sodium nitroprusside, theophylline) in vascular, intestinal and uterine smooth muscle. 2. In guinea-pig isolated taenia caeci pre-contracted with KCl (25 mM), BRL 38227 (0.1-10 microM) and noradrenaline (10 nM-100 microM) each caused concentration-dependent relaxation. Guanethidine and bretylium (50 microM) each antagonized the relaxation to BRL 38227 but not that to noradrenaline. At high concentration (500 microM), the adrenergic neurone blocking agents antagonized the action of BRL 38227 and, to some extent, that of noradrenaline. 3. In rat isolated aorta pre-contracted with noradrenaline (300 nM), BRL 38227 (0.0125-3.2 microM) and sodium nitroprusside (0.3-100 nM) each produced concentration-dependent smooth muscle relaxation. Guanethidine and bretylium (5-500 microM) each antagonized the action of BRL 38227 without antagonizing that of sodium nitroprusside. 4. Rats were pretreated with 17-beta oestradiol benzoate. Tension waves were then induced from segments of isolated, oestrogen-dominated uterus by transmural electrical stimulation or by oxytocin (0.2 nM). These tension waves were inhibited by BRL 38227 (0.025-3.2 microM) or theophylline (0.05-0.8 mM) in a concentration-dependent manner. Guanethidine (50 microM) antagonized the action of BRL 38227 in both the electrically- and oxytocin-driven tissues. In the electrically-driven tissues, guanethidine (50 microM) did not antagonize the inhibition to theophylline. 5. In KCl (25 mM)-treated guinea-pig taenia caeci, guanethidine (50 microM) inhibited the efflux of 86Rb+ evoked by BRL 38227 (10 microM) but not that evoked by noradrenaline (10 microM). In contrast, apamin(100 nM) reduced the efflux of 86Rb+ which was promoted by noradrenaline, but did not affect efflux induced by BRL 38227.6. It is concluded that the adrenergic neurone blocking agents, guanethidine and bretylium (each at 50 microM), selectively inhibit the relaxant action of BRL 38227 in vascular, intestinal and uterine smooth muscle. If this inhibition reflects direct blockade of the K+-channel (KKCO) which is opened by BRL 38227, then the adrenergic neurone blocking agents act as inhibitors selective for KKCO as opposed to the small, apamin-sensitive (SKCa) and large (BKca) conductance, Ca2"-dependent K+-channels.
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PMID:Inhibition by adrenergic neurone blocking agents of the relaxation induced by BRL 38227 in vascular, intestinal and uterine smooth muscle. 142 81

Activation of certain neurosecretory systems of the mammalian hypothalamus induces remodelling of the conformation of their neurons and glial cells. During stimulation of the hypothalamo-neurohypophysial system, astrocytic coverage of oxytocinergic somata and dendrites diminishes and their surfaces become extensively juxtaposed. In the neurohypophysis and median eminence, stimulation evokes a retraction of glial processes and an increase in the contact area between neurosecretory terminals and the perivascular space. These changes are reversible and glial coverage returns to normal upon cessation of stimulation. Neuronal-astrocytic rearrangements also occur in the arcuate nucleus in response to changes in sex steroid levels. The significance of such modifications is a matter of speculation. In the hypothalamic nuclei they may permit synaptic remodelling that takes place concurrently; in the neurohaemal structures they may facilitate neuropeptide release. We know little about the cellular mechanisms involved but glia and neurons of these systems express certain molecules implicated in cell-cell interactions in the developing central nervous system, such as the polysialylated isoform of the neural cell adhesion molecule; this may allow them to manifest their capacity for morphological plasticity in adulthood. The factors inducing the changes vary in the different structures: while oxytocin, in synergy with steroids, appears essential to the induction of the changes in the oxytocinergic system, oestrogen alone is critical in the arcuate nucleus; in the neurohypophysis noradrenaline appears important.
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PMID:Neuronal-glial and synaptic remodelling in the adult hypothalamus in response to physiological stimuli. 142 25

The reaction of secretory epithelium and myoepithelial cells in the alveoli to hand milking and i.v. injection of oxytocin and catecholamines was studied in lactating goats. The reaction of secretory cells was assessed by changes in the transepithelial (blood-milk) potential difference (PD), and the contractile reaction of myoepithelial cells by the growth of intramammary pressure (IP). The initial value of PD was 24.6 +/- 0.6 mV, that of IP 3.32 +/- 0.08 kPa (24.9 +/- 0.6 mmHg). Milking and oxytocin administration caused a rise in PD and an increase in IP. After noradrenaline and adrenaline injections two-phase PD changes and a short-term rise in IP were recorded. Isoproterenol, a beta-agonist, caused a rise in PD but did not affect IP. Phenylephrine, an alpha-agonist, caused two-phase and one-phase changes in PD. Simultaneously, a rise in IP was recorded. The results show that the reaction of the mammary gland to the substances administered is complex. Myoepithelial and secretory cells respond differently to short-term rises in the level of mediators and hormones in the blood.
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PMID:Transepithelial potential difference in the goat mammary gland and its change during hand milking, and administration of oxytocin and catecholamines. 145 32

More than 20 years following the recognition of a possible role for eicosanoids in ovarian function a physiological role for prostaglandins and/or leukotrienes in human ovulation, corpus luteum function and tubal motility remains to be demonstrated. With respect to ovarian function, the well-characterized preovulatory rise in eicosanoid production in animal species and humans, in conjunction with the large body of experimental evidence employing inhibitors of prostaglandin synthesis and replacement of individual prostaglandins, has provided strong evidence for a role in follicular rupture independent of other LH-mediated ovulatory events. The possible mechanism of prostaglandin-induced follicle rupture may involve stimulation of proteolytic activity via substances such as plasmin and PA; however, this is controversial. A role for prostaglandins in ovarian luteal function is well established in laboratory animals and large ruminant species, where PGF2 alpha derived from the uterus has been demonstrated to be the luteolytic factor. In humans, luteal function may be influenced by local intraovarian eicosanoid production, which has been suggested to involve the paracrine interaction of local ovarian hormones such as oxytocin, noradrenaline, insulin and IGFs, to name but a few. Several lines of evidence have also implicated prostaglandins as an aetiological factor in ovarian pathological states such as seen in the OHSS. However, the bulk of clinical experimental evidence to date has failed to support this contention. Prostaglandin production has likewise been well characterized in the fallopian tube in both humans and animal species. Whereas a role for prostaglandins in tubal transport has been demonstrated with animal species such as the rabbit, several studies have failed to define a similar function in humans. More recently, direct injections of prostaglandin analogues into the fallopian tube and the corpus luteum have been shown to be efficacious as a treatment for ectopic pregnancy. Whether the primary mechanism of action involves effects on tubal musculature or corpus luteum function, or is simply a local vascular effect, remains to be demonstrated. Therefore, although the physiological role for eicosanoids in ovarian and tubal function remains unclear, particularly in the human, an increasing body of recent evidence has suggested an important paracrine function for this class of cellular mediators whose interaction with other more recently characterized local ovarian factors has only begun to be recognized.
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PMID:Prostaglandins in the ovary and fallopian tube. 147 96

Microdialysis sampling was used to measure the release of oxytocin (OXY) and monoamine and amino acid transmitters from the region of the medial preoptic area (MPOA) and the bed nucleus of the stria terminalis (BNST) during parturition and suckling in sheep. Results showed that OXY and gamma-aminobutyric acid release increased in both the MPOA and BNST during parturition and suckling. Noradrenaline (NA) release increased in both structures during parturition but not during suckling. Dopamine (DA) release increased in the MPOA and decreased in the BNST during both parturition and suckling. Aspartate release increased in the MPOA during parturition, and the BNST during suckling, and glutamate release increased in the MPOA and BNST at parturition and only in the BNST during suckling. No changes in the release of serotonin or taurine occurred in these structures during parturition or suckling. In a further experiment on 6 estrogen-primed sheep, OXY (10 micrograms/ml) was infused into the MPOA via bilaterally placed microdialysis probes. This treatment inhibited rejection behavior towards lambs, but did not activate positive maternal responses. These OXY infusions also stimulated release of NA. These results show that complex patterns of neurochemical release occur in two closely related areas of the brain, the BNST and MPOA, during parturition when maternal behavior is stimulated. However, while these patterns of release are similar in the two structures, particularly at birth when maternal behavior is stimulated, they are not identical during labor contractions and suckling. The release of oxytocin within the MPOA during parturition may be important for stimulating a reduction in aggression towards lambs, although this action might be mediated via the effect of OXY on NA release.
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PMID:Oxytocin, amino acid and monoamine release in the region of the medial preoptic area and bed nucleus of the stria terminalis of the sheep during parturition and suckling. 154 Aug 26


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