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

We studied trophic effects of angiotensin II, vasopressin, cholecystokinin, and oxytocin on explanted ventral spinal cord cultures from 13- and 14-day-old rat embryos. There was a significant neurite promoting effect of the spinal cord cultures by using angiotensin II, vasopressin, and cholecystokinin. Cholecystokinin had the most potent effect at any concentrations. The minimum effective concentration was 10(-8) M in angiotensin II and vasopressin and 10(-12) M in cholecystokinin, respectively. The effect of angiotensin II and vasopressin was dependent on concentrations. However, the rate and grade of neurite appearance did not correlate with the concentrations of cholecystokinin. Oxytocin had no neurotrophic effect at any concentrations. Our results demonstrated that angiotensin II, vasopressin and cholecystokinin have neurotrophic effects on the ventral spinal cord in cultures, and may be candidates for therapeutic trials of amyotrophic lateral sclerosis.
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PMID:Trophic effect of angiotensin II, vasopressin and other peptides on the cultured ventral spinal cord of rat embryo. 188 May 32

Two days before ovulation ovarian follicles of sows were implanted with microdialysis systems (MDS) which function like artificial capillaries with exteriorized inlets and outlets. Steroid hormones and paracrine acting factors such as oxytocin (OXT) and angiotensin II (AII) diffuse from ovarian tissue into the fluid, which is pumped through the MDS and collected in fractions. This allows determination of dynamic changes of estradiol (E2), progesterone (P), OXT, and AII secretion during the pre-, peri-, and postovulatory periods in freely moving sows. More than 80% of such implanted follicles ovulate and form competent corpora lutea (CL) allowing continuation of experimentation during the early luteal phase. Follicular E2 release increases before ovulation and decreases with increasing blood LH concentrations. Twenty to 30 h after beginning of the preovulatory LH surge P secretion increases gradually. Both peptides OXT and AII are released episodically by the preovulatory follicle. During the time of decreased E2 and not yet increased P secretion, i.e. during the periovulatory period, mean AII secretion was highest in comparison to the late follicular and early luteal phase. E2 remains measurable during the early luteal phase. OXT and AII were also topically applied into the follicular wall and after ovulation into the CL. AII had no effect on steroidogenesis of both structures. Although OXT was ineffective in the follicle, in young CL it stimulated P secretion. These results indicate that the MDS can be used to study late follicular and early luteal steroid and peptide secretion. The function of OXT and AII in the follicle remains obscure, whereas OXT has a luteotropic effect in young porcine CL.
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PMID:Determination of secretion rates of estradiol, progesterone, oxytocin, and angiotensin II from tertiary follicles and freshly formed corpora lutea in freely moving sows. 195 14

A survey is given on the regulation of the formation of corticoliberin and of pro-opiomelanocortin and of ACTH, respectively, and on the significance of these compounds. The formation of pro-opiomelanocortin is furthered by corticoliberin, vasopressin, oxytocin and angiotensin II. Receptors for the binding of corticoliberin appear in numerous parts of the central nervous system. In various diseases the content of corticoliberin in the plasma and in certain tissues is changed. The inhibition of the ACTH secretion by glucocorticosteroids takes place via a decrease of the formation of corticoliberin and by a reduction of the equipment of the corticotrophic cells with receptors for its binding. The secretion of corticoliberin and of ACTH, respectively, is increased by loads, by hypoglycaemia, by blood losses, by hypoxia and by infections. In the glucocorticosteroid receptors there are 2 types with different affinity to cortisol and corticosterone.
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PMID:[Current findings in the regulation of formation of corticoliberin, pro-opiomelanocortin and ACTH as well as the efficacy of these compounds]. 196 5

1. Effects of atrial natriuretic peptide (ANP) on tension development, particulate guanylate cyclase activity and guanosine 3':5'-cyclic monophosphate (cyclic GMP) concentrations of uteri from oestrogen-treated, progesterone-treated, ovariectomized and pregnant rats were determined in vitro. 2. ANP inhibited the tension development by myometrial tissues from oestrogen-treated virgin rats and the sterile horn of 10 to 14 day pregnant rats but not of the uterus from pregnant and progesterone-treated rats. 3. Inhibition of cyclo-oxygenase and lipoxygenase activities did not restore the tocolytic activity of ANP on gravid uterus. ANP exerted a tocolytic effect on nongravid uterus submaximally stimulated by prostaglandin F2 alpha (PGF2 alpha), oxytocin, vasopressin, angiotensin II or 5-hydroxytryptamine (5-HT). 4. Ovariectomy decreased the tocolytic effects of ANP, which could be restored by oestrogen treatment. 5. The refractoriness to the tocolytic effect of ANP in pregnant rats was not accompanied by a decrease in its relaxant effects on isolated aortic strips. 6. Tocolytic effects of isoprenaline, isobutylmethyl xanthine and hydroxylamine were not influenced by pregnancy or progesterone treatment. Up to a concentration of 3 mM, sodium nitroprusside did not affect myometrial tension development. 7. Pregnancy and progesterone treatment markedly inhibited ANP-induced increases in myometrial particulate guanylate cyclase activity and cyclic GMP concentrations but did not influence the effects of ANP on aortic cyclic GMP concentrations. 8. It is concluded that exposure of the myometrium to circulating and placentally-produced progesterone is responsible for the pregnancy-induced decrease in the effects of ANP on myometrial particulate guanylate cyclase activity and cyclic GMP concentrations and in turn on myometrial tension development.
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PMID:Refractoriness of the gravid rat uterus to tocolytic and biochemical effects of atrial natriuretic peptide. 197 61

The effect of systemic angiotensin II (ANG II) administration on the posterior pituitary function was investigated in normal men. In addition, the role of endogenous opioids in the control of arginine vasopressin (AVP) and/or oxytocin (OT) responses to ANG II was evaluated with the administration of the opioid antagonist naloxone. ANG II (i.v. infusion for 60 min of successively increasing doses of 4, 8 and 16 ng/kg min; each dose for 20 min) was given to 7 normal men, alone or together with naloxone (10 or 20 mg injected i.v. just before ANG II infusion). In all subjects, control experiments with naloxone (10 or 20 mg) alone were also performed. ANG II induced a significant increase in plasma concentrations of AVP and OT. The AVP and OT responses to ANG II had a similar magnitude and followed a similar pattern. The mean peak levels of both hormones were reached at 60 min after the beginning of ANG II infusion. The administration of 10 or 20 mg naloxone alone did not modify the circulating concentrations of AVP and OT. The pretreatment with naloxone significantly increased both ANG II-induced AVP and OT increases twofold, without changing the time course and the secretory pattern of the hormonal responses. These data demonstrate that systemic administration of ANG II in man induces similar simultaneous increments in plasma levels of both AVP and OT. Furthermore, these data suggest the involvement of a naloxone-sensitive opioid mechanism in the regulation of both AVP and OT responses to ANG II in man.
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PMID:Naloxone increases the angiotensin II stimulated rise of arginine vasopressin and oxytocin secretion in man. 204 83

1. The crude aqueous/alcoholic extract (CE) of Mandevilla illustris (Apocynaceae) rhizomes was analysed against contractile response elicited by bradykinin (BK), lysyl-bradykinin (L-BK), oxytocin(Ot), acetylcholine (Ach), angiotensin II (AII) and barium chloride (BaCl2) in the isolated uterus of the rat. 2. The CE of this plant (0.5-2.0 mg/ml) caused a parallel and concentration-related rightward displacement of BK and L-BK contractile responses. Schild plot revealed a linear relationship (r close to one) and yielded nominal PA2 values of 3.6 and 3.2 respectively, but the slopes were significantly different from unity. 3. However, the anti-BK action of the CE of M. illustris was not selective to kinin action, since in the same range concentration the CE also affected uterine contractile responses induced by Ot, Ach, AII and BaCl2.
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PMID:Antagonism of kinin-induced contraction of isolated rat uterus by the crude hydroalcoholic extract from Mandevilla illustris. 205 Feb 94

Microinjection of arginine vasopressin into the lateral septum and bed nucleus of the stria terminalis of male hamsters stimulates intense flank marking and flank gland grooming, while microinjections of vasopressin in sites immediately adjacent to these areas or in the lateral ventricle are ineffective. Microinjections of oxytocin, angiotensin II and the behaviorally active C-terminal fragment of vasopressin, metabolite neuropeptide, by comparison, do not stimulate flank marking. Effective sites for vasopressin injection are clearly superimposable upon autoradiographically defined sites of high V1-receptor density. Furthermore, vasopressin-sensitive neurons in the lateral septum and bed nucleus of the stria terminalis are necessary for the expression of naturally elicited flank marking since the microinjection of a V1-receptor antagonist into these sites was able to temporarily block flank marking triggered by odors from conspecifics.
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PMID:Vasopressin in the septal area of the golden hamster controls scent marking and grooming. 208 69

Increasing evidence indirectly suggests a role for oxytocinergic neurons in the control of ingestive behaviors. The present study was aimed at directly investigating a possible effect of oxytocin on food and water intake in rats. Oxytocin, whether administered intracerebroventricularly (ICV) (1-10 micrograms/rat) or intraperitoneally (IP) (375-3,000 micrograms/kg) dose dependently inhibited food intake in freely feeding animals; in schedule-fed animals fasting for 21 h, oxytocin not only reduced food intake but also reduced the time spent eating and increased the latency to first meal. On the other hand, oxytocin antagonist d(CH2)5Tyr(Me)-[Orn8]-vasotocin, ICV injected at the dose of 10 micrograms/rat, increased food intake and time spent eating and reduced the latency to first meal; moreover, it completely prevented the effect of oxytocin. Water intake was studied both in freely drinking animals and in three different models of thirst (water deprivation, hypertonic saline administration, angiotensin II injection). In all cases, oxytocin dose dependently inhibited water intake, in a dose range of 0.1-10 micrograms/rat (ICV) or 93-750 micrograms/kg (IP). In the water deprivation model, ICV pretreatment with d(CH2)5Tyr(Me)-[Orn8]-vasotocin completely prevented the antidipsogenic effect of oxytocin. In conclusion, these data show that oxytocin directly inhibits food and water intake in rats, the effect being specifically mediated by brain oxytocin receptors. This may support the idea that the brain oxytocinergic system plays an important role in the regulation of ingestive behaviors.
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PMID:Oxytocin inhibits food and fluid intake in rats. 208 13

We investigated effects of various agents on proliferation, intracellular pH (pHi), and intracellular calcium [( Ca2+]i) of rat mesangial cells (MCs) in early passages (2-5). Serum-starved MCs incubated in HCO3- were exposed to one of the following: fetal calf serum (FCS), serotonin, angiotensin II (ANG II), arginine vasopressin (AVP), bombesin (Bom), bradykinin (BK), epidermal growth factor (EGF), epinephrine (Epi), interleukin 1 (IL-1), norepinephrine (NE), neuropeptide Y, oxytocin, substance P (SP), platelet-derived growth factor, or 12-O-tetradecanoylphorbol-13-acetate (TPA). We assessed DNA synthesis from [3H]thymidine uptake during exposure to test agent. All agents except ANG II, NE, Bom, and SP were mitogenic. When MCs were incubated in a HCO3(-) -free N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered medium, maximal mitogenic responses to FCS, AVP, and EGF were 41, 44, and 55% (P less than 0.01) lower, respectively, than those in presence of HCO3-. In absence of HCO3-, agents other than BK and IL-1 produced a biphasic pHi response characterized by a transient acidification followed by a prolonged alkalinization that was both Na(+)-dependent and amiloride-sensitive. In presence of HCO3-, agents produced only a small and gradual acidification, except for IL-1 and Epi. Addition of all agonists except IL-1, EGF, and TPA produced significant transient increases in [Ca2+]i, the magnitudes of which were similar in HCO3- and non-HCO3- buffers. These results demonstrate that, in presence of HCO3-, agents (i.e., NE and ANG II) can produce typical [Ca2+]i transients and still not cause MC proliferation. Conversely, an agent may cause proliferation without eliciting a short-term change in either [Ca2+]i or pHi (i.e., IL-1), a change in [Ca2+]i but not pHi (i.e., Epi), or a change in pHi but not [Ca2+]i (i.e., TPA). Thus, at least for MCs, proliferation in HCO3- can be dissociated from early agonist-induced changes in pHi and [Ca2+]i.
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PMID:Effects of mitogens and other agents on rat mesangial cell proliferation, pH, and Ca2+. 211 98

The ability of a number of drugs and neuropeptides to stimulate phosphoinositide metabolism in cultured bovine adrenal medullary cells has been assessed. Low concentrations (10 nM) of angiotensin II, bradykinin, histamine, arginine-vasopressin, and bombesin, and high (10 microM) concentrations of oxytocin, prostaglandins E1, and E2, beta-endorphin, and neurotensin stimulated significant accumulation of [3H]inositol phosphates in adrenal medullary cells preloaded with [3H)]inositol. Bradykinin stimulated a significant response at concentration as low as 10pM, with an EC50 of approximately 0.5 nM. The response was markedly inhibited by the bradykinin B2 antagonist [Thi5,8,D-Phe7] bradykinin but not the B1 antagonist [Des-Arg9,Leu8] bradykinin. Higher concentrations of bombesin and neurotensin were required to elicit a response (10 nM and 10 microM respectively). The bombesin response was sensitive to inhibition by the bombesin antagonist [D-Arg1,D-Pro2,D-Trp7,9Leu11]-substance P. In contrast, the neurotensin response was not reduced by the NT1 antagonist [D-Trp11]-neurotensin. These results indicate there are a number of agents that can stimulate phosphatidylinositide hydrolysis in the adrenal medullary cells by acting on different classes of receptors. Such a range of diverse agonists that stimulate inositol phosphate formation will facilitate further analysis of the phosphatidylinositide breakdown in chromaffin cell function.
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PMID:Receptor stimulated formation of inositol phosphates in cultures of bovine adrenal medullary cells: the effects of bradykinin, bombesin and neurotensin. 217 99


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