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)

Endogenous opioid peptides inhibit secretion of oxytocin during dehydration, hemorrhage and parturition and attenuate release of vasopressin by tail electroshock. Diverse agents were used to stimulate the hypothalamo-neurohypophysial system to investigate the hypothesis that if oxytocin (or vasopressin) release were inhibited by opioid peptides regardless of the stimulus, the site of opiate action may be in the final common pathway (i.e. the magnocellular neuron) or on pituicytes in the neural lobe. Using male Sprague-Dawley rats, we therefore investigated the effect of an opiate receptor antagonist, naloxone (5 mg/kg s.c.), on the plasma concentrations of oxytocin and vasopressin elevated by various pharmacologic stimuli, including histamine (10 mg/kg i.p.), nicotine (0.15 or 1.5 mg/kg i.p.), isoproterenol (30 or 120 micrograms/kg i.m.) and increased [NaCl] in cerebrospinal fluid (CSF; 10 microliter artificial CSF containing 1 M NaCl i.v.t.). Control animals received saline (0.85%) or artificial CSF (containing 0.16 M NaCl). Animals were decapitated 60 s (increases[NaCl] in CSF) or 10 min after the stimulus or vehicle. Vasopressin and oxytocin were extracted from plasma and quantified by RIA. The concentrations of oxytocin and vasopressin in plasma were elevated (p less than 0.05) by histamine, isoproterenol (30 and 120 micrograms/kg), increases[NaCl] in CSF, and nicotine at the higher (1.5 mg/kg) but not lower (0.15 mg/kg) dose. Naloxone increased further (p less than 0.05) the concentration of oxytocin in plasma after histamine, nicotine (0.15 and 1.5 mg/kg), isoproterenol (30 and 120 micrograms/kg) and increases[NaCl] in CSF. Naloxone also increased (p less than 0.05) oxytocin concentration in controls receiving CSF or saline.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Naloxone effects on plasma vasopressin and oxytocin concentrations elevated by histamine, nicotine, isoproterenol and an acute increase in [NaCl] in cerebrospinal fluid. 379 91

We studied the concentration of neurophysin I (hNPI) and II (hNPII), the hypothalamo-pituitary carriers of vasopressin and oxytocin, in CSF of depressed and schizophrenic patients and age matched controls. Mean hNPI values were lower and mean hNPII values greater in schizophrenics than in controls. Lower hNPI values were observed in unipolar patients than in controls. In bipolar patients however, higher hNPI values were present. Significantly higher hNPII values were observed in bipolar patients than in controls; no difference was present between unipolars and controls. A positive correlation was observed with age in controls and bipolars for hNPII. These data emphasize the interest of studying the neurohypophysal function in affective illness and in schizophrenia.
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PMID:Cerebrospinal fluid neurophysins in affective illness and in schizophrenia. 648 3

The content of vasopressin (AVP) and oxytocin (OXT) in the septum, hippocampus, hypothalamus and cortex was determined at 5 min and 24 hr after peripheral (intraperitoneal) administration of histamine (20.0 mg/kg) and pentylenetetrazol (45.0 mg/kg) and in the cerebrospinal fluid at 24 hr after pentylenetetrazol treatment. At 5 min after administration of histamine the AVP content in the septum was increased whereas the OXT level in the various areas was not changed. At 24 hr, neurohypophyseal peptide contents were unaffected in the brain regions analyzed. Pentylenetetrazol did not alter AVP content at 5 min after its administration, however, the OXT level in the septum and the cortex was diminished. At 24 hr after administration of pentylenetetrazol a decreased AVP content in the hippocampus and in the cortex was observed. In contrast, OXT content in the cortex was increased at this time. AVP and OXT levels in CSF were not changed at 24 hr following pentylenetetrazol treatment. The present results suggest that the levels of neurohypophyseal hormones can be differentially altered in particular brain regions at short- (5 min) and long- (24 hr) term intervals after treatment with histamine or pentylenetetrazol. Long-term changes in AVP and OXT levels after pentylenetetrazol may be implicated in the amnesic properties of this convulsive drug. Furthermore, the present findings point to a possible relationship with previously reported pentylenetetrazol-induced changes in peptide levels in the CSF.
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PMID:Vasopressin and oxytocin content in cerebrospinal fluid and in various brain areas after administration of histamine and pentylenetetrazol. 664 96

The neuropil located ventral to the SON was investigated by the use of immunoperoxidase staining for neurophysins, oxytocin and vasopressin, and electron microscopy. The study was performed in six groups of rats: 1) control; 2) infusion of isotonic saline into the CSF; 3) infusion of hypertonic saline into the CSF; 4) drinking hypertonic saline for 4 days; 5) same as group 4 but injection of colchicine into the CSF on second day of dehydration; 6) salt loading for 3 months. In the control rats the ventral neuropil contained a few immunoreactive processes, the general morphology of which was completely different from that of the neurosecretory axons emerging from the SON at its dorsal aspect. In rats of groups 3 to 6 the ventral processes (VP) became loaded with neurosecretory granules, whereas the perikarya and axons were depleted. Based on their general morphology and reactivity pattern it is suggested that the VP are dendrites. Most of these "dendrites" were embedded in a glial cushion formed by the processes of a particular type of marginal glia. Some of these "dendrites" enveloped an arteriole penetrating the optic tract. All VP were rich in synaptic contacts. The possibility that the VP of neurosecretory cells may be functionally related to the subarachnoid CSF and the arteriolar blood flow is discussed.
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PMID:Immunocytochemistry and ultrastructure of the neuropil located ventral to the rat supraoptic nucleus. 671 4

Histamine administered intraperitoneally increased, in a dose-dependent manner, AVP, OXT and PRL levels in plasma of rats, whereas alpha-MSH levels were not affected. Levels of AVP in plasma after histamine 20.0 mg/kg treatment were approximately 100-fold higher than those of controls, while OXT and PRL levels were approximately 7-fold higher after this treatment. CSF content of AVP, OXT, PRL and alpha-MSH was not influenced by histamine, indicating that a stimulated release of hormones from the pituitary into the blood is not accompanied by a concomitant increase of secretion of these hormones into the CSF. Convulsions induced by pentylenetetrazol were accompanied by a temporary increase in AVP levels and by strongly and consistently elevated OXT levels in plasma. PRL and alpha-MSH plasma levels were affected in a biphasic manner. A convulsion type 1 induced elevated PRL levels and diminished alpha-MSH levels, while a convulsion type 2 had no effect on plasma PRL concentration, but increased the concentration of alpha-MSH. Only the level of OXT in CSF was increased after a pentylenetetrazol-induced convulsion type 1. The present data suggest that histamine affects the release of AVP, while pentylenetetrazol might act more specifically on the OXT-releasing system. Furthermore, a possible relationship between the pentylenetetrazol-induced increase of OXT levels in the CSF and amnesia is suggested.
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PMID:Hypophyseal hormone levels in blood and cerebrospinal fluid in response to histamine and pentylenetetrazol. 715 99

Neural connections linking the four magnocellular nuclei, i.e., the paired supraoptic (SON) and paraventricular (PVN) nuclei, may contribute to the simultaneous and parallel changes in firing patterns of oxytocinergic neurons during reflex milk ejection. To investigate these neural connections in the absence of suckling, intranuclear release of oxytocin (OT) was stimulated by microdialysis of hypertonic CSF containing 1 M NaCl (HS-CSF) into the right SON area and glucose metabolism of both SONs and PVNs and the neural lobe of virgin and lactating (10-12 day) rats was mapped by the autoradiographic [14C]deoxyglucose (DG) method. OT in the microdialysates and in plasma, obtained before and after 80-90 min of dialysis with CSF or HS-CSF, was quantified by RIA. In both virgin and lactating rats, microdialysis of HS-CSF unilaterally into the SON area significantly (p < 0.05) increased release of OT in the nucleus and into plasma, which was associated with enhanced (p < 0.05) metabolic activity in the ipsilateral and contralateral SON and the neural lobe but not in either PVN. Compared with virgins, lactating rats were less active, had lower (p < 0.05) glucose utilization in the hypothalamo-neurohypophysial system, and less (p < 0.05) OT in plasma during microdialysis of HS-CSF into the SON area. The osmotic stimulus did not activate neural structures (suprachiasmatic and medial amygdaloid nuclei) near the SON in either hemisphere. Thus, neural connections or, less likely, transport of OT via the subarachnoid space, may function to recruit activation of cells in the contralateral SON following hypertonic stimulation of cells in the other SON.
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PMID:Crosstalk in the magnocellular system during osmotic stimulation of one supraoptic nucleus. 819 18

The central nucleus of the amygdala (CEA) is considered to play a major role in the expression of behavioral, autonomic, and neuroendocrine components of the stress response. The present study was designed to examine possible modulating effects of the neuropeptides arginine-8-vasopressin (AVP) and oxytocin (OXT) on functioning of the CEA in male Wistar rats. Heart rate, neuroendocrine parameters, and behavioral activity were repeatedly measured before, during, and after local administration of several doses of AVP and OXT under stress-free resting conditions. In comparison with control artificial-CSF infusion, AVP infusion in the lowest dose (20 pg) caused in a part of the animals a long-lasting decrease in heart rate, i.e., bradycardia, without affecting behavioral activity. In contrast, local infusion with high doses of AVP and OXT (2 ng) induced a transient cardioacceleration concomitant with an increase in behavioral activity. Moreover, these latter effects of AVP could effectively be blocked by pretreatment with a selective OXT receptor antagonist. These findings suggest that higher doses of AVP are effective via agonistic action on OXT receptors in the CEA. A strong correlation existed between the magnitudes of the tachycardiac response and behavioral activation. Thus, heart rate increase by OXT receptor stimulation is possibly due to somatic-autonomic coupling rather than genuine autonomic activation. Additionally, plasma corticosterone, but not epinephrine and norepinephrine, concentrations were elevated in response to AVP and OXT infusions. In conclusion, these results suggest that vasopressinergic influences on CEA function involve two receptor mechanisms possibly related to differential output systems.
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PMID:Cardiac, neuroendocrine, and behavioral effects of central amygdaloid vasopressinergic and oxytocinergic mechanisms under stress-free conditions in rats. 822 Nov 55

Tetrodotoxin (TTX) was used to (1) distinguish between axonal and dendritic/somatic release of vasopressin (VP) and oxytocin (OT) within the supraoptic nucleus (SON) and (2) to determine whether neuronal inputs trigger intranuclear peptide release in the response to osmotic stimulation. Microdialysis was used to administer TTX (10(-6) M or 10(-4)M) bilaterally into the SON with simultaneous monitoring of central and peripheral peptide release and mean arterial pressure in urethane-anesthetized male rats. Osmotic stimuli were given via the microdialysis probe (1 M NaCl-artificial CSF) or injected intraperitoneally (3.5 M NaCl; 600 mu l/100 g b.w.) SON perfusion with TTX did not alter basal intranuclear VP or OT release or the intranuclear peptide response to direct NaCl stimulation of the SON. However, TTX treatment abolished the effect of peripheral osmotic stimulation on central peptide release. Basal plasma peptide levels were significantly reduced by TTX, e.g. decreases of 94.8 and 75.8% for VP and OT, respectively. TTX also blocked the peripheral endocrine and cardiovascular responses to both modes of osmotic stimulation. The TTX insensitivity of directly stimulated intranuclear release suggests nonsynaptic peptide release from dendrites and/or cell bodies. The ability of TTX to abolish the central peptide response to systemic osmotic stimulation demonstrates that intranuclear release is a part of a cascade produced by osmotic activation of multisynaptic pathways.
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PMID:Effects of tetrodotoxin on osmotically stimulated central and peripheral vasopressin and oxytocin release. 875 Dec 88

Intracerebroventricular (i.c.v.) administration of the kappa-opiate receptor agonist U 69.593 induces a rapid and short lasting suppression of oxytocin (OXT) levels in plasma of water deprived rats, whereas only a tendency towards a suppression of vasopressin (AVP) levels in plasma is observed. No change in neurohypophyseal hormone levels in CSF occurs following i.c.v. administration of U 69.593 at the various times points studied. It is concluded that, upon i.c.v. administration, the suppressive influence of U 69.593 is much weaker than that of the dynorphins and that neurophypophyseal hormone levels in CSF behave differently from those in the peripheral circulation.
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PMID:Effect of central administration of the kappa-opiate receptor agonist U 69.593 on neurohypophyseal hormone levels in blood and cerebrospinal fluid. 892 7

This review considers the potential reduction of embryo mortality in vitro and in vivo in ruminants. Data on cytokines provided by different fields of reproductive immunology and biology were collated. Because of the crucial importance of the local interactions between the embryo and its dam, the expression of growth-factor and cytokine genes was analysed in the embryo proper, trophoblast, oviduct and endometrium by reverse transcriptase polymerase chain reaction in sheep and in cattle during the pre- and periimplantation periods. Many deleterious cytokines, such as tumour necrosis factor-alpha, interferon-gamma (IFN-gamma), interleukin-2 (IL-2), and beneficial cytokines, such as transforming growth factor-beta, leukaemia inhibiting factor, colony-stimulating factor-1 (CSF-1), granulocyte-macrophage CSF, IL-1, IL-3, IL-4, IL-6, IL-10 and IFN-tau appeared to be involved in embryo survival in ruminants and other species. Their administration is efficient in a murine experimental model (CBA/J x DBA/2) of embryonic and fetal mortality. For instance, recombinant ovine IFN-tau (roIFN-tau) injected at the moment of implantation drastically reduces embryonic mortality in this model. In ruminants, roIFN-tau and recombinant bovine IFN-tau are very efficient in maintaining progesterone luteal secretion in cyclic animals. The involvement of IFN-tau in the mechanisms of maternal pregnancy recognition are particularly detailed in relation to inhibition of 13,14 dihydro-15-keto-prostaglandin F2 alpha (PGFM) pulses and oxytocin uterine receptivity. A synthetic model of the anti-luteolytic effects of IFN-tau on the endometrial cell is proposed. Finally, the particular potential of serum pregnancy-specific proteins (PSPs: PSPB, PSP60, pregnancy-associated glycoprotein) for monitoring embryo survival, with examples given for cattle and sheep is underlined.
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PMID:Recent developments and potentialities for reducing embryo mortality in ruminants: the role of IFN-tau and other cytokines in early pregnancy. 926 83


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