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)

In the developing and adult human paraventricular (PVN) and supraoptic (SON) nucleus, a large proportion of neurons contains the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH). In the present study we investigated the possible colocalization of TH with oxytocin (OXT) or vasopressin (VP) in the adult and neonatal PVN and SON. Adjacent paraffin sections were incubated simultaneously with two antibodies: a polyclonal against TH and a monoclonal against OXT or VP and stained with a double peroxidase-antiperoxidase/alkaline phosphatase method. We observed that TH-immunoreactive(IR) perikarya in the human PVN and SON were also positive for OXT or VP. A clear difference between the neonates and adult cases of our sample was observed in the proportion of TH-IR neurons that colocalize OXT or VP. In the neonates the majority of the TH-IR perikarya was also stained for VP, while only few TH-IR neurons were also positive for OXT. The opposite was observed in the adults, where the majority of the double-stained TH-IR neurons colocalizes OXT while only few TH-IR perikarya appear to contain VP. Our study establishes the colocalization of TH with OXT or VP in the adult and neonatal PVN and SON and indicates that antemortem factors such as perinatal hypoxia might increase TH-immunoreactivity of the VP neurons in man.
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PMID:Colocalization of tyrosine hydroxylase with oxytocin or vasopressin in neurons of the human paraventricular and supraoptic nucleus. 769 71

The distribution of central nerve fibers in the rat pineal complex was studied by means of fluorescence- and immunohistochemistry and electron microscopy. At 7 days after bilateral superior cervical ganglionectomy (SCG-X), blue-green fluorescent (catecholaminergic) fibers and tyrosine hydroxylase- and serotonin-immunoreactive fibers originating from the brainstem were detected in the deep pineal and the pineal stalk. These fibers were not observed in the superficial pineal. In some animals, a few oxytocin-immunopositive fibers were found in the proximal portion of the superficial pineal. The nerve fibers were submicroscopically counted in transverse sections at 6 levels with an interval of about 200 microns each in the pineal stalk. The number of nerve fibers showed 3 peaks, at the proximal-most, the intermediate and the distal-most levels. On the other hand, various types of synapses, axo-dendritic, axo-axonic and axo-pinealocytic, and many free terminals, were observed in the stalk. In these synapses, the majority of presynaptic swellings contained only clear vesicles, but some of them possessed aminergic (5-hydroxydopamine- or 5,6-dihidroxytriptamine-positive) vesicles or elementary granules. The reduction in the number of nerve fibers was most conspicuous in the distal-most level after the SCG-X. Based on these results, it is supposed that the proximal peak is formed by the central fibers going further to the stalk and turning back to the brain, the intermediate peak is formed by the terminal arborizations of the central fibers, and the distal peak shows penetration of the sympathetic fibers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Nerve fibers originating from the brain in the rat pineal complex. 769 5

Vaginocervical stimulation, that occurs during mating or with the birth of pups, is believed to induce specific sexual and maternal behaviours in the rat as well as stimulating a number of neuroendocrine responses including the secretion of oxytocin, prolactin and luteinizing hormone. Since the medial preoptic area has been implicated in the induction of maternal behaviour, the expression of the immediate-early gene product Fos was compared between non-pregnant, late pregnant and parturient rats. Although no difference was detected in the number of Fos-positive neuronal profiles in the preoptic area of non-pregnant and late-pregnant rats, a large increase was observed in the medial preoptic nucleus and the anteroventral periventricular region, as well as in the hypothalamic supraoptic nucleus, of parturient rats. Double labelling for Fos and tyrosine hydroxylase immunoreactivity in the brainstem of parturient rats showed the activation of catecholaminergic neurons in both the nucleus of the tractus solitarius and in the ventrolateral medulla that may form part of the afferent pathway from the uterus and cervix to the preoptic area and hypothalamus.
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PMID:Fos expression within regions of the preoptic area, hypothalamus and brainstem during pregnancy and parturition. 771 54

To identify brain neurons that participate in the acute phase response, rat brains were examined immunocytochemically for Fos protein following the intravenous administration of bacterial endotoxin (lipopolysaccharide, LPS). Two to three hours after the injection of LPS, 150 micrograms/kg body weight, to adult male Long-Evans rats, a consistent anatomic pattern of Fos immunostained cell nuclei is seen. In the brain stem, prominant Fos immunostaining is induced in tyrosine hydroxylase immunoreactive neurons of the caudal ventral-lateral medulla (the A1 cell group), in both tyrosine hydroxylase positive and negative neurons of nu. tractus solitarius, in the parabrachial nu., and in a few neurons of the locus ceruleus. In the hypothalamus, endotoxin induces Fos expression in magnocellular neurons of the paraventricular and supraoptic nuclei and internuclear cell groups. A higher percentage of oxytocin-immunoreactive cells is double labeled for Fos nuclear immunostaining than vasopressin-immunoreactive cells. A minority of somatostatin immunoreactive periventricular hypothalamic neurons are Fos positive. Other hypothalamic nuclei that contain endotoxin-induced Fos nuclear immunostaining include the parvocellular neurons of the paraventricular nu., the dorsomedial and arcuate nuclei, the lateral hypothalamus, the dorsal hypothalamic area (zona incerta), and the median nucleus of the preoptic area. LPS induces numerous Fos-positive neurons in regions known to respond to a variety of stressful stimuli; these regions include the preoptic area, bed nucleus of the stria terminalis, lateral septum, and the central and medial nuclei of the amygdala. Moreover, Fos nuclear immunostaining is seen in neurons of circumventricular organs: the organum vasculosum of the lamina terminalis, the subfornical organ, and the area postrema. The maximum intensity of Fos nuclear immunostaining occurs 2-3 h after endotoxin administration and declines thereafter. It is attenuated by pretreatment with indomethacin, 25 mg/kg body weight Sc, or dexamethasone, 1 mg/kg IP. These observations are consistent with the participation of a variety of brain neuronal systems in the acute phase response and elucidate the functional neuroanatomy of that response at the cellular level.
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PMID:Anatomic patterns of Fos immunostaining in rat brain following systemic endotoxin administration. 771 98

Fos and other immediate early gene products are used as markers for neuronal activity. We identified Fos immunocytochemically after KCI-induced depolarization of cultured hypothalamic neurons. Five-day cultures were treated for 1 h with 50 mM KCI or media and fixed at 0, 0.5, 1, 2, and 4 h posttreatment. Sequential immunocytochemistry was performed to identify Fos immunoreactivity in tyrosine hydroxylase (TH)-immunoreactive (-ir) or oxytocin (OT)-ir neurons. Activated neurons [brown cells (TH-ir or OT-ir) with purple nuclei (Fos-ir)] were counted microscopically. KCI treatment resulted in an increased percentage of Fos-ir TH-ir and OT-ir neurons over control levels over the time course examined. Fos-ir peaked in TH-ir neurons at 0.5 to 1 h posttreatment, with levels returning to baseline at 4 h. Fos-ir in OT-ir neurons peaked at 2 h, and remained elevated at 4 h, showing prolonged activation. These results demonstrate that KCI-induced depolarization of cultured hypothalamic neurons increases Fos with a different time course in TH-ir vs. OT-ir neurons.
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PMID:Fos activation in cultured tyrosine hydroxylase and oxytocin immunoreactive neurons. 771

The various hypothalamic nuclei show very different patterns of change in ageing. These patterns are a basis for changes in biological rhythms, hormones, autonomous functions or behavior. The suprachiasmatic nucleus (SCN) coordinates circadian and circannual rhythms. A marked seasonal and circadian variation in the vasopressin (AVP) cell number of the SCN was observed in relation to the variation in photoperiod. During normal ageing, the circadian variation and number of AVP-expressing neurons in the SCN decreases. The sexually dimorphic nucleus (SDN), intermediate nucleus or INAH-1 is localized between the supraoptic and paraventricular nucleus (PVN). In adult men the SDN is twice as large as in adult women. In girls, the SDN shows a first period of decreasing cell numbers during prepubertal development, leading to sexual dimorphism. During ageing a decrease in cell number is found in both sexes. The cells of the supraoptic nucleus and PVN produce AVP or oxytocin and coexpress tyrosine hydroxylase. These nuclei are examples of neuron populations that seem to stay perfectly intact in ageing. Parvicellular corticotropin-releasing-hormone (CRH)-containing neurons are found throughout the PVN. CRH neurons in the PVN are activated in the course of ageing, as indicated by their increase in number and AVP coexpression. Part of the infundibular (or arcuate) nucleus, the subventricular nucleus, contains hypertrophic neurons in postmenopausal women. The hypertrophied neurons contain neurokinin-B (NKB), substance P and estrogen receptors and probably act on LHRH neurons as interneurons. The NKB neurons may also be involved in the initiation of menopausal flushes. The nucleus tuberalis lateralis might be involved in feeding behavior and metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ageing of the human hypothalamus. 772 Dec 67

Pituitary adenylate cyclase activating polypeptide (PACAP) is a recently discovered member of the secretion family. 1. PACAP is a well conserved peptide during the phylogenesis. It has two bioactive amidated forms: PACAP38 and PACAP27 with 38 and 27 residues, respectively. 2. PACAP and its receptors are widely distributed in the central and peripheral nervous systems and in non-neural tissues. 3. In the central nervous system PACAP immunoreactive neuronal elements have been observed in the hypothalamus (magno- and parvocellular cell groups), both layers of the median eminence, the septum, the thalamus, the amygdaloid complex, the hippocampus, and various regions of the cortex. 4. In the periphery, PACAP was found in small sensory and parasympathetic neurons. 5. In the hypothalamus PACAP partially colocalizes with oxytocin- and tyrosine hydroxylase-immunoreactivities. In the septum there is no colocalization between the two immunoreactivities, but PACAP- and tyrosine hydroxylase-immunoreactive fibers were often found to establish synaptic contacts with the same, unlabeled dendrite. It was reported that in the periphery, in sensory neurons PACAP colocalized with substance-P and in parasympathetic neurons with acetylcholin. 6. PACAP functions as a neurotransmitter, hypothalamic releasing factor, posterior pituitary hormone, and trophic factor of the nervous tissue. PACAP also participates in neuro-immunoendocrine mechanisms.
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PMID:Present status of knowledge about the distribution and colocalization of PACAP in the forebrain. 772 24

1. This study aimed to establish the site at which morphine acts to inhibit oxytocin release in response to peripheral administration of cholecystokinin (CCK). 2. Conscious rats were given morphine or vehicle followed by CCK or vehicle (I.V.). Fos immunoreactivity was apparent 90 min after CCK injection in the supraoptic nucleus of vehicle- but not morphine-pretreated animals. 3. In the dorsomedial (C2/A2) and the ventrolateral (C1/A1) regions of the brainstem, about half of the cells immunoreactive for tyrosine hydroxylase (TH) expressed Fos-like protein after CCK injection. In the C2/A2 region, 20% of the Fos-positive cells also showed TH immunoreactivity, whereas in the C1/A1 region 68% did so. Morphine treatment did not significantly change the number of cells expressing Fos immunoreactivity, or the percentage of TH-positive cells expressing Fos-like protein. 4. Amine release was measured in the supraoptic nucleus of urethane-anaesthetized rats using a microdialysis probe. An I.V. injection of CCK increased the concentrations in the dialysate of noradrenaline and serotonin, but not of either adrenaline or dopamine. Pretreatment with morphine (I.V.) blocked the effects of CCK in a naloxone-reversible manner. 5. Inclusion of morphine in the dialysate also blocked the increase in noradrenaline and serotonin in response to CCK in a naloxone-reversible manner. 6. These observations indicate that morphine acts near or within the supraoptic nucleus to block CCK-evoked noradrenaline release presynaptically. This presynaptic action of morphine may be a cause of the blockade of oxytocin release after CCK.
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PMID:Presynaptic actions of morphine: blockade of cholecystokinin-induced noradrenaline release in the rat supraoptic nucleus. 773 Sep 90

We investigated whether delivery could be induced with pulsatile oxytocin and whether such treatment activated neurons in the supraoptic nucleus (SON) and putative afferent neurons in the nucleus tractus solitarii and ventrolateral medulla, as seen during spontaneous parturition. Rats were implanted with a jugular venous cannula 1 day before the expected term and on the next morning were given a pulse of oxytocin or saline every 10 min for 4 h. Pulses of 10 and 20 mU oxytocin induced delivery in 77% (14 of 18) of rats, whereas none of the control animals (0 of 9) gave birth during the treatment. Lower doses of oxytocin were not effective at this time in inducing delivery. Animals were killed either before (prepartum groups) or during (parturient groups) delivery, and the brains were processed for immunocytochemistry. Oxytocin treatment induced Fos expression in SON and brain stem neurons in both parturient rats and rats in which parturition was not induced. Fos expression in all sites was significantly higher than that in control prepartum rats, but was similar in extent and distribution to that in spontaneous parturient rats. In the brain stem, a substantial proportion of Fos-immunoreactive cells contained tyrosine hydroxylase-like immunoreactivity, and the number of these cells was increased in response to oxytocin treatment. As only very few Fos-immunoreactive nuclei in either the SON or the nucleus tractus solitarii were observed in virgin rats injected with oxytocin, we suggest that intermittent oxytocin injections in late pregnant rats induce strong uterine activity, which can stimulate magnocellular and putative afferent neurons even before the expulsion of pups.
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PMID:Induction of uterine activity with oxytocin in late pregnant rats replicates the expression of c-fos in neuroendocrine and brain stem neurons as seen during parturition. 782 26

In neurons, which are post-mitotic cells, a structural and biochemical plasticity occurs, namely for the mediators. The magnocellular hypothalamic neurons innervating the neural lobe are a favourable model for the study of the dynamic aspects of neuropeptides expression. In fact, they synthetize these peptides in large amounts, as a function of the physiological or experimental conditions. In addition to the major neuropeptides, oxytocin (OT) and vasopressin (VP) which are contained in control rats within different neuronal populations, immunocytochemistry and in situ hybridization used alone or in combination in the same preparations have revealed other neuropeptides and corresponding mRNAs respectively. These multiple labellings demonstrate that after osmotic stimulation or during lactation some neurons are able to synthetize OT and VP simultaneously, together with galanin and even tyrosine hydroxylase (but not catecholamines). Similarly, hypophysectomy or transection of the pituitary stalk differentially modify the contents in mRNA coding for VP, OT and galanin. These results have also been described in other neuronal types such as spinal ganglia sensory neurons, suggesting possible mechanisms at different levels of genetic expression: transcription, translation, post-translational events and possibly interneuronal exchanges of mRNA. The in vivo regulation of this neurochemical plasticity probably involves the innervation of these neurons and perhaps the colocalized peptides themselves. In fact, galanin selectively inhibits the expression of VP but not that of OT. Functional implications of the neuronal phenotypic plasticity in the adaptation of the nervous system to the changing physiological conditions are discussed, together with its possible implications in pathology and therapeutics.
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PMID:[A model of phenotypic plasticity: the hypothalamo-posthypophyseal neurons]. 783 3


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