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)

Depression is frequently associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which leads to repeated episodes of hypercortisolemia. Hypothalamic paraventricular neurons are believed to trigger these processes by aberrant generation and/or release of corticotropin releasing hormone, oxytocin, vasopressin, and nitric oxide (NO). Recent findings from two independent laboratories have demonstrated that the suprachiasmatic nucleus, which in part controls the cellular activity of paraventricular neurons (PVN), is also involved in affective disorder. The aim of the present study was to elucidate by stereological analysis, whether suprachiasmatic nucleus (SCN) nitric oxide synthase and neurophysin generating neurons are affected in neuropsychiatric disorders. We show that compared to controls the number of nitric oxide synthase immunoreactive neurons is greatly reduced both in depression and in schizophrenia. In subjects with affective disorder there was a correlation between the number of NOS-expressing cells and duration of treatment with antidepressants. The number of neurophysin-expressing SCN neurons was also fewer in cases with mood disorder. It is concluded that SCN-derived NO may be a relevant pathophysiological factor in neuropsychiatric disorders.
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PMID:Hypothalamic nitric oxide synthase in affective disorder: focus on the suprachiasmatic nucleus. 1619 95

Metabolic peptides such as orexin and neuropeptide Y (NPY) exert profound effects on feeding but also act centrally to stimulate the hypothalamo-pituitary-adrenal (HPA) axis. In late pregnancy the HPA axis is hyporesponsive to centrally administered orexin-A, which signals to the HPA axis, in part, via arcuate NPY neurones. We investigated whether reduced HPA axis responses to orexin may be a consequence of down-regulated NPY signaling to the paraventricular nucleus (PVN) in pregnancy. Pregnant (d 21) and virgin rats were blood sampled for ACTH, corticosterone, and oxytocin (also a stress hormone in rats) before and after intracerebroventricular NPY or vehicle. Behavior was monitored. Rats were killed 4 h after NPY and brains removed for in situ hybridization. In another experiment rats were given vehicle or NPY, perfuse fixed 90 min later, and brain sections processed for Fos and oxytocin immunocytochemistry. NPY significantly increased ACTH, corticosterone and oxytocin secretion in the virgins but had no such effect on ACTH or oxytocin in the pregnant rats; the corticosterone response to NPY was markedly attenuated in pregnant rats. NPY increased CRH and vasopressin mRNA expression in the parvocellular PVN and stimulated Fos expression in magnocellular supraoptic and PVN oxytocin neurones of virgin but not pregnant rats. NPY increased food intake and drinking similarly in virgin and pregnant rats. Thus, neuroendocrine stress responses to central NPY are absent in late pregnancy, whereas ingestive behavioral responses are intact. These changes may explain the similarly attenuated HPA response to centrally administered orexin-A and will favor anabolic adaptations in pregnancy.
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PMID:Neuroendocrine stress but not feeding responses to centrally administered neuropeptide Y are suppressed in pregnant rats. 1667 22

Although numerous data showing severe morphological impairment of magnocellular and parvocellular hypothalamic neurons due to chronic alcoholic consumption have been gathered from animal experiments, only one study (Harding et al., 1996) was performed on POST MORTEM human brain. This study showed a reduction in the number of vasopressin (VP)-immunoreactive neurons in the supraoptic (SON) and paraventricular (PVN) nuclei, but did not provide any data regarding the effect of chronic alcohol intake on human parvocellular neurons. In order to assess whether the changes observed in the animal model also occur in humans and provide a structural basis for the results of clinical tests, we performed immunohistochemical and morphometric analysis of magnocellular (VP and oxytocin, OT) and parvocellular (corticotropin-releasing hormone, CRH) neurons in post-mortem brains of patients afflicted with chronic alcoholic disease. We analyzed 26-male alcoholics and 22 age-matched controls divided into two age groups--"young" (< 40 yr) and "old" (> 40 yr). Hypothalamic sections were stained for OT, VP, and CRH. The analysis revealed: 1) decrease in VP-immunoreactivity in the SON and PVN as well as OT-immunoreactivity in the SON in alcoholic patients; 2) increase in OT-immunoreactivity in the PVN; 3) increase in CRH-immunoreactivity in parvocellular neurons in the PVN. Furthermore, the proportion of cells containing CRH and VP was increased in alcoholics. These findings indicate that chronic alcohol consumption does indeed impair the morphology of magnocellular neurons. The enhancement of CRH-immunoreactivity and increased co-production of CRH and VP in parvocellular neurons may be due to a decline in glucocorticoid production, implied by the hypoplasic impairment of adrenal cortex we observed in alcoholics during the course of this study.
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PMID:Effects of chronic alcoholic disease on magnocellular and parvocellular hypothalamic neurons in men. 1682 20

Neuroendocrine responses to stress vary between sexes and reproductive states and are influenced by the type of stressor. Stress responses are attenuated in some physiological states, such as lactation and conditions of low visceral adipose tissue. Moreover, some individuals within a species characteristically display reduced stress responses. The neuroendocrine mechanisms for stress hyporesponsiveness are likely to include reduced synthesis and secretion of corticotropin releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus as a result of enhanced glucocorticoid negative feedback and/or reduced noradrenergic stimulatory input from the brain stem. A major limitation of research to date is the lack of direct measures of CRH and AVP secretion. Attenuated stress responsiveness is also commonly associated with reduced pituitary responsiveness to CRH and AVP. The possible roles of inhibitory central inputs to CRH and AVP neurons and of oxytocin and prolactin in attenuating the HPA axis responses to stress are unknown.
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PMID:Neuroendocrine mechanisms of innate states of attenuated responsiveness of the hypothalamo-pituitary adrenal axis to stress. 1693 Jun 83

Oxytocin (OT) is involved in the stimulation of secretion of anterior pituitary hormones in females during the periovulatory and periparturient periods. In the present study we examined the role of OT in control of ACTH, beta-endorphin, LH and PRL secretion in vitro from dispersed anterior pituitary cells collected from gilts during the luteal (Days 10-12; n=6) and follicular (Days 18-20; n=5) phases of the estrous cycle. Isolated anterior pituitary cells (1 x 10(6)/ml) were transferred into 24-well plates, separately for each animal, and were pre-incubated for three days at 37 degrees C in atmosphere of 5% CO(2) and 95% air. The cells which attached to the dishes were incubated (3.5 h, 37 degrees C) in McCoy's medium in the absence (control) or in the presence of the following factors: CRH alone (10(-10), 10(-9), 10(-8), 10(-7) M), OT alone (10(-8), 10(-7), 10(-6) M), LVP alone (10(-7) M), OT (10(-7) M) plus CRH (10(-9) M) and LVP (10(-7) M) plus CRH (10(-9) M) for studying ACTH and beta-endorphin secretion; OT alone (10(-8), 10(-7), 10(-6) M), GnRH alone (100 ng/ml), CRH alone (10(-9) M), OT (10(-7) M) plus GnRH (100 ng/ml) and OT (10(-7) M) plus CRH (10(-9) M) for studying LH and PRL secretion. Concentrations of the studied hormones in media were analyzed by RIA. Oxytocin alone increased ACTH (at doses 10(-7), 10(-6) M), beta-endorphin (at dose 10(-8) M), LH (at dose 10(-8) M) and PRL (at doses 10(-7), 10(-6) M) secretion by pituitary cells isolated only from luteal-phase gilts. None of the studied hormone concentrations in the medium was increased in response to OT when pituitary cells of follicular-phase gilts were examined. Oxytocin in combination with CRH exerted an additive effect on beta-endorphin secretion during the luteal phase. Summarizing, in the present study the stimulatory effect of oxytocin on ACTH, beta-endorphin, LH and PRL secretion by pituitary cells isolated from gilts during the luteal phase was demonstrated. However, the cells collected from follicular-phase gilts appeared to be unresponsive to OT. Moreover, interaction between OT and CRH in affecting beta-endorphin secretion was shown. These results suggest that OT may be transiently involved in the modulation of anterior pituitary hormone secretion in cyclic pigs.
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PMID:Effects of oxytocin alone and in combination with selected hypothalamic hormones on ACTH, beta-endorphin, LH and PRL secretion by anterior pituitary cells of cyclic pigs. 1717 93

Estrogens have numerous effects on the brain, both in adulthood and during development. These actions of estrogen are mediated by two distinct estrogen receptor (ER) systems, ER alpha (ERalpha) and ER beta (ERbeta). In brain, ERalpha plays a critical role in regulating reproductive neuroendocrine function and behavior, however, a definitive role for ERbeta in any neurobiological function has been slow in forthcoming. Clues to the function of ERbeta in the central nervous system can be gleaned from the neuroanatomical distribution of ERbeta and the phenotypes of neurons that express ERbeta. ERbeta immunoreactivity has been found in populations of GnRH, CRH, vasopressin, oxytocin and prolactin containing neurons in the hypothalamus. Utilizing subtype-selective estrogen receptor agonists can help determine the roles for ERbeta in non-reproductive behaviors in rat models. ERbeta-selective agonists exert potent anxiolytic activity when animals were tested in a number of behavioral paradigms. Consistent with this, ERbeta-selective agonists also inhibited the ACTH and corticosterone response to stress. In contrast, ERalpha selective agonists were found to be anxiogenic and correspondingly increased the hormonal stress response. Taken together, our studies implicate ERbeta as an important modulator of some non-reproductive neurobiological systems. The molecular and neuroanatomical targets of estrogen that are mediated by ERbeta remain to be determined. A number of splice variants of ERbeta mRNA have been reported in brain tissue. Imaging of eGFP labeled chimeric receptor proteins transfected into cell lines shows that ERbeta splice variation can alter trafficking patterns and function. The originally described ERbeta (herein termed ERbeta1) is characterized by possessing a high affinity for estradiol. Similar to ERalpha, it is localized in the nucleus and is trafficked to nuclear sites termed "hyperspeckles" following ligand binding. In contrast, ERbeta2 contains an 18 amino acid insert within the ligand-binding domain and as a result can be best described as a low affinity form of ERbeta. A delta3 (delta3) variant of ERbeta has a deletion of the 3rd exon (coding for the second half of the DNA-binding domain) and as a result does not bind an estrogen response element in DNA. delta3 variants are trafficked to a unique low abundance and larger nuclear site following ligand binding. A delta4 (delta4) variant lacks exon 4 and as a result is localized to the cytoplasm. The amount of individual splice variant mRNAs varies depending upon brain region. Examination of neuropeptide promoter regulation by ERbeta splice variants demonstrates that ERbeta functions as a constitutively active transcription factor. Moreover, it appears that splice variation of ERbeta alters its ability to regulate transcription in a promoter-dependent and ligand-dependent fashion.
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PMID:Estrogen receptor beta in the brain: from form to function. 1766 59

Children become oriented to the world, in part, by coming to understand something of the experiences of others. The facial expressions that people make are an avenue for understanding something about them, as are the diverse forms of bodily responses emitted and interpreted by individuals. People with autism often find bodily communications to be aversive, thereby limiting what they can learn from others during social interactions. The amygdala is an important area of the brain, amongst others, for integrating the internal milieu with the social ambiance. Individuals with autism consistently demonstrate dysregulation of amygdala function. Diverse regions of the amygdala, which contain neuropeptides, figure in the appraisal systems that underlie behavioral approach and avoidance responses. One neuropeptide linked to social recognition and approach behaviors is oxytocin (which is known to be decreased in autistic individuals) and another neuropeptide corticotropin releasing hormone is tied to avoidance behaviors. A neuroendocrine hypothesis is suggested to account for some of the features associated with autism.
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PMID:Autism and the amygdala: an endocrine hypothesis. 1768 56

Adiponectin is an adipocyte derived hormone which acts in the brain to modulate energy homeostasis and autonomic function. The paraventricular nucleus of the hypothalamus (PVN) which plays a key role in controlling pituitary hormone secretion has been suggested to be a central target for adiponectin actions. A number of hormones produced by PVN neurons have been implicated in the regulation of energy homeostasis including oxytocin, corticotropin releasing hormone and thyrotropin releasing hormone. In the present study we investigated the role of adiponectin in controlling the excitability of magnocellular (MNC--oxytocin or vasopressin secreting) neurons within the PVN. Using RT-PCR techniques we have shown expression of both adiponectin receptors in the PVN. Patch clamp recordings from MNC neurons in hypothalamic slices have also identified mixed (27% hyperpolarization, 42% depolarization) effects of adiponectin in modulating the excitability of the majority of MNC neurons tested. These effects are maintained when cells are placed in synaptic isolation using tetrodotoxin. Additionally we combined electrophysiological recordings with single cell RT-PCR to examine the actions of adiponectin on MNC neurons which expressed oxytocin only, vasopressin only, or both oxytocin and vasopressin mRNA and assess the profile of receptor expression in these subgroups. Adiponectin was found to hyperpolarize 100% of oxytocin neurons tested (n = 6), while vasopressin cells, while all affected (n = 6), showed mixed responses. Further analysis indicates oxytocin neurons express both receptors (6/7) while vasopressin neurons express either both receptors (3/8) or one receptor (5/8). In contrast 6/6 oxytocin/vasopressin neurons were unaffected by adiponectin. Co-expressing oxytocin and vasopressin neurons express neither receptor (4/6). The results presented in this study suggest that adiponectin plays specific roles in controlling the excitability oxytocin secreting neurons, actions which correlate with the current literature showing increased oxytocin secretion in the obese population.
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PMID:Adiponectin selectively inhibits oxytocin neurons of the paraventricular nucleus of the hypothalamus. 1794 8

Nesfatin-1, a newly discovered satiety molecule, is located in the hypothalamic nuclei, including the paraventricular nucleus (PVN) and supraoptic nucleus (SON). In this study, fine localization and regulation of nesfatin-1 neurons in the PVN and SON were investigated by immunohistochemistry of neuropeptides and c-Fos. In the PVN, 24% of nesfatin-1 neurons overlapped with oxytocin, 18% with vasopressin, 13% with CRH, and 12% with TRH neurons. In the SON, 35% of nesfatin-1 neurons overlapped with oxytocin and 28% with vasopressin. After a 48-h fast, refeeding for 2 h dramatically increased the number of nesfatin-1 neurons expressing c-Fos immunoreactivity by approximately 10 times in the PVN and 30 times in the SON, compared with the fasting controls. In the SON, refeeding also significantly increased the number of nesfatin-1-immunoreactive neurons and NUCB2 mRNA expression, compared with fasting. These results indicate that nesfatin-1 neurons in the PVN and SON highly overlap with oxytocin and vasopressin neurons and that they are activated markedly by refeeding. Feeding-activated nesfatin-1 neurons in the PVN and SON could play a role in the postprandial regulation of feeding behavior and energy homeostasis.
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PMID:Nesfatin-1 neurons in paraventricular and supraoptic nuclei of the rat hypothalamus coexpress oxytocin and vasopressin and are activated by refeeding. 1804 95

The aim of the thesis was to investigate in male Wistar rats, the involvement of serotonin (5-HT) and 5-HT receptors in the regulation of the gene expression of hypothalamic hormones and in the secretion of the pituitary gland hormones prolactin (PRL), adrenocorticotropic hormone (ACTH), vasopressin (AVP) and oxytocin in basal and stress conditions. Furthermore, to study the significance of some distinctive central nuclei in these processes, and the metabolism of 5-HT in the hypothalamus and the dorsal raphe nucleus (DRN). The experiments were focused on (1) determination of involved neurons and nuclei (2) the hypothalamic level and (3) the pituitary gland level of regulation. The studies were typically performed in vivo but some studies were performed in vitro. Stereotactically neurotoxic lesion with 5,7-dihydroxy-5-HT in the dorsal raphe nucleus (DRN) or the hypothalamic paraventricular nucleus (PVN) reduced the ACTH and AVP response to stress, indicating an importance of these structures for this response. In situ hybridization on rat brain slices with oligopeptides showed an increase of corticotropin releasing hormone (CRH) mRNA in the PVN and proopiomelanocortin in the anterior pituitary lobe upon stimulation of the 5-HT1A, 5-HT1B, 5-HT2A and 5-HT2C receptors. Stimulation of 5-HT2A+2C receptors increased AVP mRNA in the PVN but not in the supraoptic nucleus (SON), whereas the level of oxytocin (OT) mRNA was increased both in the SON and the PVN and this effect was in addition mediated via 5-HT1A+1B receptors. Serotonin infused directly into the PVN by microdialysis stimulated local release of AVP. CRH was found to have a major role but not a complete responsibility in the 5-HT-induced release of ACTH, since immunoneutralisation of CRH inhibited the POMC gene expression and the ACTH response and since 5-HT and 5-HT antagonists were able to modulate the ACTH release from anterior pituitary gland cells in vitro. Through the years of investigation, the classification of the 7 main groups of 5-HT receptors (5-HT1 - 5-HT7) has changed due to molecular biological characterisation of the receptors and new receptors have been identified. With a battery of 5-HT agonists and antagonists several pharmacological experiments were performed with systemically or central administration of compounds and radioimmuno assay of plasma for pituitary gland hormone levels. Specific substances were not available for all 5-HT receptors and subreceptors thus some conclusions are a based on combination of experiments. The 5-HT induced PRL response is mediated via 5-HT1A, 5-HT2A, 5-HT2C and 5-HT3 receptors. In addition an involvement of 5-HT1B, 5-HT5 or 5-HT7 receptors seem possible. The ACTH response to 5-HT is mediated via 5-HT1A, 5-HT1B, 5-HT2A and 5-HT2C receptors and an involvement of the 5-HT4, 5-HT5 and 5-HT7 receptors is proposed. Peripheral secretion of AVP upon stimulation with 5-HT is mediated via 5-HT2C, 5-HT4 and 5-HT7 receptors but not 5-HT1A receptors. The secretion of OT is primarily mediated via 5-HT1A, 5-HT2C and 5-HT4 receptors and probably also 5-HT1B, 5-HT2A, 5-HT5A and 5-HT7 receptors. Physical and psychological stress activates hippocampal and hypothalamic 5-HT neurons. In contrast to other stress factors, restraint stress increases the content of 5-HT in the DRN but do not increase the metabolism of 5-HT and does not induce changes in hypothalamic levels of 5-HT. Large variations are found in the literature with different kinds of stress, different measurements and different time schedules. Restraint or ether stress induced secretion of PRL involves 5-HT2 and 5-HT3 receptors, whereas the ACTH secretion is mediated via 5-HT1A, 5-HT2A and 5-HT2C receptors. In the present study restraint stress increased AVP secretion, but opposite findings has reported possibly due to differences in the stress procedure. The 5-HT2, 5-HT3 and 5-HT4 receptor is involved in the AVP response to restraint whereas the OT response involves the 5-HT1A and the 5-HT2 receptor. The 5-HT2 receptor is involved in the OT response to dehydration or haemorrhage, whereas the AVP responses to these stressors probably do not involve 5-HT. It can be concluded that 5-HT is involved in basal and stress-induced regulation of PRL, ACTH, AVP and oxytocin mainly via the 5-HT2A+2C receptors but other receptors are also important but differs from hormone to hormone. Serotonin affect the secretion of CRH and ACTH both at the hypothalamic, pituitary portal and pituitary gland level, and possibly also at the adrenal level.
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PMID:Studies on the neuroendocrine role of serotonin. 1820 78


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