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)

A method is described for flow cytometric analysis and fluorescence-activated cell sorting of small populations of neurons following dissociation of fixed brain tissue and immunofluorescent labeling of intracellular antigens. This method has been successfully applied to neurophysin-containing magnocellular neurons of the rat supraoptic (SON) and paraventricular (PVN) hypothalamic nuclei. These neurons constitute a rare population in the context of flow cytometry, comprising less than 2% of all cells present in dissociated tissue punches of SON and PVN. Following labeling with anti-neurophysins sera and fluorescein-conjugated second antibody, a highly enriched population containing 80-85% neurophysin-positive neurons was isolated by fluorescence-activated cell sorting. Recovery of 29% of all neurophysin-containing neurons in the SON/PVN was achieved. Perikarya were recovered largely intact, frequently with attached proximal dendritic processes. Applications of this method include purification of specific neuronal types for use as immunogens in production of monoclonal antibodies to cell-type-specific antigens, and rapid surveys of fluorescent lectin or other ligand binding to cell populations identified by the presence of particular intracellular antigens.
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PMID:A flow cytometric method for intracellular labeling and purification of rare neuronal populations: isolation of fixed neurophysin neurons. 373 Aug 38

The hypothalamo-neurohypophysial system offers a unique example in the adult mammalian central nervous system (CNS) of a functional and structural plasticity related to a physiological state. During lactation, oxytocin neurones evolve a synchronized electrical activation which permits pulsatile hormone release at milk ejection. At the same time, in the supraoptic (SON) and paraventricular nuclei, glial coverage of neurones diminishes, so that large portions of their surface membrane become directly juxtaposed; synaptic remodelling also associates pairs of neurones through the formation of common presynaptic terminals. These structural changes, reversible after weaning, affect exclusively oxytocinergic neurones and could facilitate their synchronized electrical activity. As several observations suggest that oxytocin itself is released centrally, we have examined the effect of prolonged intracerebroventricular infusions of oxytocin on the structure of the SON of non-lactating animals. We report here that the peptide indeed engenders the structural reorganization characteristic of the oxytocin system when it is physiologically activated. Similar infusion of vasopressin has no effect. Our observations thus demonstrate that a central neuropeptide can induce anatomical changes in the adult CNS, and suggest that oxytocin can regulate its own release by contributing to the dramatic restructuring of the nuclei containing the neurones responsible for its secretion.
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PMID:Oxytocin induces morphological plasticity in the adult hypothalamo-neurohypophysial system. 374 54

35S-labeled synthetic oligodeoxyribonucleotide probes were used to measure levels of vasopressin (VP) and oxytocin (OT) mRNAs in rat hypothalamus by quantitative in situ hybridization histochemistry (ISHH). VP and OT mRNA-containing cells were seen in the paraventricular (PVN) and supraoptic (SON) nuclei. VP mRNA was found to increase five-fold in the parvocellular region of the PVN after adrenalectomy while no changes occurred in magnocellular VP or OT mRNA levels. In the Brattleboro rat, VP mRNA levels were decreased and OT mRNA levels increased in the magnocellular regions. RNA species containing the VP introns were present at one fortieth of the level of processed VP mRNA in control rats. We also performed ISHH followed by immunohistochemistry on the same sections. We found that VP and its encoding mRNA were always located together as were OT-neurophysin and its encoding mRNA. In this study, we extend previous work by showing the characteristic distributions in the PVN and SON of VP and OT mRNA-containing cells and by measuring neuropeptide mRNA changes.
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PMID:Vasopressin and oxytocin mRNAs in adrenalectomized and Brattleboro rats: analysis by quantitative in situ hybridization histochemistry. 382 59

A recent study has shown that vasopressin (AVP) cells in the human supraoptic (SON) and paraventricular (PVN) nuclei increase in size after 60 years of age, suggesting that AVP production is increased in senescence. In the present study, the same brain material was used for the determination of nucleolar size in immunocytochemically identified AVP and oxytocin (OXT) neurons as an additional parameter for peptide production. A strong correlation was found between nucleolar size and cell size, both in AVP and OXT neurons. Nucleolar size of AVP but not of OXT neurons increased significantly in senescence. Observations in brains from patients with senile dementia of the Alzheimer type (SDAT) were commensurate with their ages. These results strongly support the hypothesis that AVP neurons in the SON and PVN are activated in old age.
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PMID:Activation of vasopressin neurons in the human supraoptic and paraventricular nucleus in senescence and senile dementia. 389 63

Light microscopic studies in our laboratory have indicated that the lateral septum, amygdala, and ventral subiculum project in a perinuclear fashion to the paraventricular (PVN), supraoptic (SON), and suprachiasmatic (SCN) nuclei (Oldfield et al., '82; Silverman and Oldfield, '84). In the present paper a combined anterograde HRP and immunocytochemical procedure has been used to determine the connectivity between these limbic efferents and peptide-containing processes emanating from the above mentioned hypothalamic nuclei. Synaptic associations were found to exist between efferents from (1) the septum and both vasopressin (VP)- and oxytocin (OX)-positive dendrites derived from cells in the PVN and SON, (2) the septum and VP dendrites dorsal to the SCN, (3) the ventral subiculum and both VP and OX dendrites arising from the PVN and SON, and (iv) the amygdala and VP dendrites from the PVN. These observations help clarify an apparent discrepancy between electrophysiological data, in which limbic efferents have been shown to influence the activity of VP and OX neurons in the PVN and SON, and anatomical evidence which indicates only a perinuclear innervation from these sites not encroaching on the hypothalamic nuclei themselves. In each case the synaptic connections are made on dendrites external to the nucleus: those lateral and ventrolateral to the PVN, dorsal to the SON, and dorsal or dorsolateral to the SCN.
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PMID:A combined electron microscopic HRP and immunocytochemical study of the limbic projections to rat hypothalamic nuclei containing vasopressin and oxytocin neurons. 396 36

The neuropeptides vasopressin (AVP) and oxytocin (OXT) are supposed to be involved not only in peripheral functions (e.g. diuresis, labour and lactation) but also in central processes that are frequently disturbed during aging and senile dementia (e.g. fluid and electrolyte homeostasis and cognitive functions). A concomitant decrease in activity of the hypothalamo-neurohypophyseal system (HNS) with aging has been postulated in the literature, but has not yet been established. In order to investigate possible age-related changes in the human HNS, immunocytochemically identified AVP and OXT neurons in the paraventricular and supraoptic nucleus (PVN and SON) were analysed morphometrically in subjects from 10 to 93 years of age, including patients with senile dementia of the Alzheimer type (SDAT). Cell size was used as a parameter for peptide production. Mean profile area of OXT cells did not show any significant changes with increasing age. Mean profile area of AVP cells, however, showed an initial decrease up to the sixth decade of life, after which a gradual increase was observed. Size of AVP and OXT cell nuclei did not change significantly with aging. Observations in brains from patients with SDAT were within the range for their age group. The present results do not support degeneration or diminished function of the HNS in senescence or SDAT, as generally presumed in the literature, but suggest an activation of AVP cells after 80 years of age. The activation of AVP cells in senescence is in accordance with previous findings in the aged Wistar rat.
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PMID:The vasopressin and oxytocin neurons in the human supraoptic and paraventricular nucleus; changes with aging and in senile dementia. 404 17

The content of arginine vasopressin and oxytocin in various extrahypothalamic sites of the rat brain and spinal cord was determined by specific radioimmunoassays after lesions had been made in either the paraventricular (PVN), supraoptic (SON) or suprachiasmatic nuclei (SCN). In some animals all 3 nuclei were destroyed together. The PVN provided a considerable amount of the vasopressin innervation of the solitary tract nucleus, and most of that in the spinal cord. Oxytocin was removed from some areas after lesions of the PVN and, again, most of this peptide was lost from the spinal cord. Lesions of the SCN did not appear to be followed by significant quantitative changes in either hormone in any of the areas studied. Lesions of the SON resulted in loss of oxytocin, particularly in the periventricular grey and some other areas, suggesting that extrahypothalamic projections from this nucleus may be more important than was previously assumed. Lesions of all 3 nuclei which included destruction of accessory hypothalamic nuclei resulted in a much more widespread loss of vasopressin and oxytocin, but there was preservation of both peptides in the dorsal raphe nucleus and much of those present in the locus coeruleus. It is concluded that the contribution of the classical hypothalamic nuclei to the extrahypothalamic content of vasopressin and oxytocin in rat brain is less than was originally believed, and that there are areas of the brain such as the locus coeruleus and dorsal raphe nucleus in which the source of these peptides may be outside the hypothalamus.
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PMID:Effects of lesions in the hypothalamic paraventricular, supraoptic and suprachiasmatic nuclei on vasopressin and oxytocin in rat brain and spinal cord. 405 70

The in vitro synthesis of catecholamines and the secretion of vasopressin (AVP) and oxytocin (OT) was measured in localized regions of the hypothalamo-neurohypophyseal system in the spontaneously hypertensive rat (SHR). The posterior pituitary (PP), median eminence (ME) and supraoptic (SON) and paraventricular (PVN) nuclear regions were incubated in vitro in media containing 3H-tyrosine. Media and tissue levels of AVP and OT were measured as well as norepinephrine and dopamine content and biosynthesis. There were no differences in peptide release in either the PP, ME or SON. However, there was a marked increase in peptide release from the PVN of the SHR. Media AVP levels were 0.3 pg/ml/micrograms protein in the WKY as compared to 2.1 pg/ml/micrograms protein in the SHR. OT release was increased 2 fold, from 0.85 to 1.7 pg/ml/micrograms protein. PVN content of both AVP and OT was significantly lower in the SHR. ME and SON peptide levels were not changed, while neurohypophyseal AVP levels were increased in the SHR. With regard to the catecholamines appreciable norepinephrine synthesis was measured in the PVN and SON while there was little 3H-norepinephrine in the ME or PP. In the hypertensive rat, there was an increase in norepinephrine synthesis in the PVN with no change in the SON. These results provide further support for fundamental changes in the catecholaminergic and peptidergic systems of the hypothalamo-neurohypophyseal axis of the SHR.
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PMID:Catecholamine biosynthesis and vasopressin and oxytocin secretion in the spontaneously hypertensive rat: an in vitro study of localized brain regions. 408 Jun 11

The present paper reviews recent work conducted in our laboratory on vasopressin neurons either grown in culture or transplanted into vasopressin deficient rats. The in vitro model of reaggregated cell culture used the anterior hypothalamus, including vasopressin neurons of the SON from normal timed-pregnant LE rats of similar ages used in our in vivo model. Various cells were co-cultured with their known target tissue, the posterior pituitary to analyze further the influence of the target tissue on hormone production. At a designated end point, cultured cells were fixed and stained immunocytochemically for vasopressin and neurophysin. Radioimmunoassay of the samples was performed for vasopressin quantification. Hypothalamic cells from all ages produced vasopressin (VP). The co-culturing of hypothalamus with posterior pituitary produced a significant increase in VP. Correlative transplantation studies were conducted using timed-pregnant Long-Evans (LE) rats at various days post coitus (dpc) and neonatal tissue from 0- and 5-day old rat pups. Animals survived about 40 days then were perfused and their brains processed for vasopressin and neurophysin thick-section immunocytochemistry. The results showed that the capability for survival of younger grafts was much greater than that of older tissue. With this paper, we have shown that the reaggregation of anterior hypothalamic cells in a culture system can be used for microassay of neurosecretory activity. These data suggest a close correlation between the ability of a neuron to survive transplantation and its stage of development. With the present studies, we have shown that neurons not fully differentiated maintain a greater degree of plasticity than older tissue and are better able to survive the rigors of transplantation and that various manipulations of environmental factors have an effect on brain development at critical times.
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PMID:In vitro and in vivo studies on development and regeneration of vasopressin neurons. 648 53

The activity of the hypothalamo-neurohypophyseal system (HNS) was determined in male Wistar rats from 3 to 32 months of age. Plasma levels of vasopressin (AVP) and oxytocin (OXT) were measured by means of a radioimmunoassay. In addition, the distribution of the Golgi apparatus marker enzyme thiamine-pyrophosphatase (TPP-ase) was measured as a parameter for neurosecretory activity in the hypothalamic supraoptic and paraventricular nuclei (SON and PVN). Plasma levels of radioimmunoassayable AVP were increased in the 32-month-old animals. Plasma levels of radioimmunoassayable OXT in 32-month-old animals did not differ from the levels found in the youngest group, but were higher than in 11-month-old animals. Neurosecretory activity in the SON was similar in 3- and 32-month-old animals, whereas in the PVN neurosecretory activity was increased in the 32-month-old animals. Urine excretion decreased between 6 and 11 months of age and remained on the same level until 32 months of age. In other words, instead of a loss of HNS function as has been suggested in the literature, an increased neurosecretory activity was observed in aged rats.
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PMID:Activation of vasopressinergic and oxytocinergic neurons during aging in the Wistar rat. 662 86


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