Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Estrogen receptor (ER)-beta, unlike ER-alpha, is localized in the hypothalamic paraventricular nucleus (PVN) which also contains neuropeptide synthesizing neurons, such as oxytocin (OT), arginine vasopressin (AVP) and corticotropin-releasing hormone (CRH). Although it is known that some ER-beta containing neurons co-express OT and AVP, but not CRH, in the PVN, it is not yet determined whether ER-beta activation may indeed play a role in estrogenic regulation on syntheses of these neuropeptides. In the present study, we tested this hypothesis by comparing the effects of estrogen on the levels of OT, AVP and CRH messenger RNA (mRNA) between ER-beta knockout (betaERKO) and wild type (WT) control male mice. Mice were gonadectomized and implanted with either a pellet containing estradiol benzoate (2.5-5.0 microg/day) or a placebo pellet for 21 days. In situ hybridization histochemistry revealed that estrogen treatment resulted in a significant increase in OT transcripts (151.6+/-6.0%) and a decrease in AVP transcripts (77.8+/-5.2%) in the PVN of WT mice, compared to the placebo control group. This estrogenic regulation of OT and AVP mRNA levels in the PVN was completely abolished in betaERKO mice. Similar genotype differences in the effects of estrogen on the numbers of OT- and AVP-containing cells were found in immunocytochemical studies performed in a separate set of mice. On the other hand, the expression of CRH mRNA in the PVN was not affected by estrogen treatment in either WT or betaERKO mice. Furthermore, estrogen did not cause any changes in the levels of OT or AVP mRNA, regardless of genotype, in the supraoptic nucleus where, unlike in rats, ER-beta containing neurons are rarely found in mice. Finally, estrogen significantly increased OT mRNA levels in both betaERKO and WT in the medial preoptic area, which contains both ER-alpha and ER-beta. These results suggest that ER-beta activation may play a critical role in estrogenic regulation of OT and AVP gene expression in the PVN.
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PMID:Estrogen receptor-beta regulates transcript levels for oxytocin and arginine vasopressin in the hypothalamic paraventricular nucleus of male mice. 1253 18

Topographical distribution of estrogen receptor-beta (ER-beta)-synthesizing oxytocin (OT) and vasopressin (VP) neurons was studied in the hypothalamic paraventricular and supraoptic nuclei (PVH; SO) of ovariectomized rats. In distinct subregions, 45-98% of OT neurons and 88-99% of VP neurons exhibited ER-beta immunoreactivity that was confined to cell nuclei. Neuronal populations differed markedly with respect to the intensity of the ER-beta signal. Magnocellular OT neurons in the PVH, SO, and accessory cell groups typically contained low levels of the ER-beta signal; in contrast, robust receptor labeling was displayed by OT cells in the ventral subdivision of medial parvicellular subnucleus and in the caudal PVH (dorsal subdivision of medial parvicellular subnucleus and lateral parvicellular subnucleus). Estrogen receptor-beta signal was generally more intense and present in higher proportions of magnocellular and parvicellular VP vs. OT neurons of similar topography. Immunocytochemical observations were confirmed via triple-label in situ hybridization, an approach combining use of digoxigenin-, fluorescein-, and 35S-labeled cRNA hybridization probes. Further, ER-beta mRNA was also detectable in corticotropin-releasing hormone neurons in the parvicellular PVH. Finally, double-label immunocytochemical analysis of human autopsy samples showed that subsets of OT and VP neurons also express ER-beta in the human. These neuroanatomical studies provide detailed information about the topographical distribution and cellular abundance of ER-beta within subsets of hypothalamic OT and VP neurons in the rat. The variable receptor content may indicate the differential responsiveness to estrogen in distinct OT and VP neuronal populations. In addition, a relevance of these findings to the human hypothalamus is suggested.
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PMID:Estrogen receptor-beta in oxytocin and vasopressin neurons of the rat and human hypothalamus: Immunocytochemical and in situ hybridization studies. 1511 94

Estrogen receptor-alpha (ER-alpha) and ER-beta exhibit fine differences in their distributions in the rodent forebrain, and one such difference is observed in the paraventricular (PVN) and supraoptic (SON) nuclei. To investigate the functional significance of ER in these brain areas, we examined the neuropeptide characteristics of ER-expressing neurons in the PVN and SON of female rats by using dual-label immunocytochemistry. The distributions of ER-alpha immunoreactivity (ir) and ER-beta ir were nonoverlapping in the PVN and SON. Nuclear ER-alpha ir was found in a population of thyrotropin-releasing hormone (TRH)-expressing neurons in the PVN (5.93% +/- 1.20% SEM), but not in any other identified cell phenotype of the PVN and SON. The phenotype of neurons with the highest percentage expressing ER-beta was found to be prolactin (PRL) immunoreactive in both the parvocellular (84.95% +/- 4.11%) and the magnocellular (84.76% +/- 3.40%) parts of the PVN as well as the SON (87.57% +/- 4.64%). Similarly, most vasopressin-immunoreactive neurons were also ER-beta positive in the PVN (66.14% +/- 2.47%) and SON (72.42% +/- 4.51%). In contrast, although a high percentage of oxytocin (OXY) neurons coexpressed ER-beta in the PVN (84.39% +/- 2.99%), there was very little ER-beta/OXY colocalization in the SON. Low levels of corticotropin-releasing hormone neurons also expressed ER-beta ir in the PVN (12.57% +/- 1.99%), but there was no ER-beta colocalization with TRH. In summary, these findings further support the possibility of direct effects of estrogen on neuropeptide expression and implicate estrogen involvement in the regulation of various aspects of neuroendocrine function.
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PMID:Estrogen receptor-beta, but not estrogen receptor-alpha, is expressed in prolactin neurons of the female rat paraventricular and supraoptic nuclei: comparison with other neuropeptides. 1571 9