Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyproheptadine, a nonselective 5-hydroxytryptamine receptor blocking agent, reduces ACTH and beta-endorphin secretion from the ACTH-producing tumors. A 35-year-old female suffering from Cushing's disease due to microadenoma of the pituitary gland has been followed since the age of 15. Subtotal adrenalectomy followed by total adrenalectomy, pituitary irradiation, and transsphenoidal hypophysectomy, combined with second radiotherapy of the pituitary, were unsuccessful in achieving remission of the disease. Remission was achieved with cyproheptadine up to a dosage of 24 mg/day. Every attempt to discontinue cyproheptadine treatment was accompanied by recurrence of the disease. This is the first case of Cushing's disease in which cyproheptadine treatment has been the only efficacious therapy for a period of 11 yr. Cyproheptadine may be an alternative long-term therapy for Cushing's disease when other methods of treatment fail.
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PMID:Cyproheptadine treatment in Cushing's disease. 886 5

Two series of experiments were conducted to investigate the role of corticotropin-releasing hormone (CRH) in the effects of 5-hydroxytryptamine (5-HT) on energy intake and energy expenditure. The first set of experiments was carried out to confirm the influence of 5-HT1A-, 5-HT1B-, 5-HT2A/2C-receptor agonists on the activation of the hypothalamic-pituitary-adrenal axis. Plasma corticosterone levels were measured, and a double-immunolabeling procedure was used to determine whether the neuronal activity marker, c-Fos protein (Fos), could be found within brain neurons containing CRH after treatments with 5-HT1A-, 5-HT1B-, 5-HT2A/2C-receptor agonists. The second series of experiments was conducted to assess the involvement of CRH in the effects of 5-HT on food intake and metabolic rate (VO2). The effects of the 5-HT1A-, 5-HT1B-, 5-HT2A/2C-receptor agonists on food intake and VO2 were measured in rats treated with the CRH antagonist, alpha-helical CRH-(9-41). In both experiments rats were intraperitoneally injected with either a vehicle (NaCl 0.9%), the 5-HT1A-receptor agonist (+/-)-8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide (8-OH-DPAT), the 5-HT1B-receptor agonist 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole succinate (RU-24969), or the 5-HT2A/2C-receptor agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (DOI). Fos immunoreactivity was detectable within the CRH-containing neurons of the paraventricular nucleus of the hypothalamus (PVH) after injection of each of the 5-HT-receptor agonists used. The CRH antagonist alpha-helical CRH-(9-41) attenuated the increases in metabolic rate induced by DOI and 8-OH-DPAT. alpha-Helical CRH did not, however, prevent the effects of RU-24969 and DOI on either nocturnal metabolic rate or food intake. The present results provide further evidence for a role of CRH in 5-HT-mediated thermogenic effect, which likely involves the 5-HT2A/2C receptor during the day and the 5-HT1A receptor during the night. Moreover, these results do not support a role for CRH in 5-HT anorectic effects, which likely involves 5-HT1B and 5-HT2A/2C receptors. Finally, the results of this study indicate that the stimulation of CRH-containing neurons located in the PVH does not necessarily predict changes in food intake and energy expenditure.
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PMID:Role of CRH in the effects of 5-HT-receptor agonists on food intake and metabolic rate. 894 58

Quantitative autoradiography was used to examine possible adaptive changes in serotonin 5-HT1B/1D and 5-HT2A/2C receptor binding sites in adult rat basal ganglia, after partial or severe lesions of serotonergic neurons produced by intraraphe injections of variable amounts of 5,7-dihydroxytryptamine. In controls, the 5-HT1B/1D sites labeled with S-CM-G[125I]TNH2 were evenly distributed in the core and the shell of the nucleus accumbens. The density of 5-HT1B/1D sites was higher in the ventral than dorsal part of the striatum and no regional differences were detected along the rostrocaudal axis of the structure. The 5-HT2A/2C sites labeled with [125I]DOI were preferentially distributed in the mediodorsal striatum and higher densities were detected in the shell than core of the nucleus accumbens. Following 5,7-dihydroxytryptamine injections, there were no changes in binding of either receptor subtype after partial lesions entailing 80-90% 5-HT depletions. After severe 5-HT depletions (over 95%), large increases in 5-HT1B/1D binding were observed in the substantia nigra (78%), but no changes took place in the globus pallidus. Increases in 5-HT1B/1D binding were also detected in the shell of the nucleus accumbens (27%). Similar sized increases in 5-HT2A/2C binding (22%) were restricted to the medial striatum. The present results suggest a preferential association between 5-HT1B/1D receptors and the striatonigral neurons containing substance P, as indicated by the striatal distribution of these receptors and their selective increases in the substantia nigra after severe 5-HT deprivation. We recently proposed a similar relationship between the 5-HT4 receptors and the striatopallidal neurons containing met-enkephalin. Moreover, the increases in 5-HT1B/1D binding in the substantia nigra and in the shell of the nucleus accumbens reinforce the view of an implication of this receptor subtype in motor functions. In contrast, the prominent increases in 5-HT2A/2C binding after severe 5-HT deprivation as restricted to the medial region of the striatum and suggest up-regulation of most probably 5-HT2C receptors in a region implicated in cognitive functions.
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PMID:Selective increases in serotonin 5-HT1B/1D and 5-HT2A/2C binding sites in adult rat basal ganglia following lesions of serotonergic neurons. 963 May 49

The serotonin receptors involved in the secretion of adrenocorticotropin hormone (ACTH) were investigated in conscious adult male rats. Administration of serotonin (5-HT), 5-hydroxytryptophan (5-HTP) in combination with the serotonin reuptake inhibitor fluoxetine (Flx), or of the 5-HT agonists 8-OH-DPAT (5-HT1A), 5-carboxamido-tryptamine (5-HT1A+1B+5A+7), RU 24969 (5-HT1B+1A), DOI (5-HT2A+2c), S-alpha-methyl-5-HT (5-HT2A+2B+2c), MK212 (5-HT2B+2c), or methyl-chlorophenyl-piperazine (5-HT2A+2c) dose-dependently stimulated ACTH secretion. The 5-HT3 agonist 2-methyl-5-HT had no effect. Administration of a 5-HT1 agonist in combination with any of the 5-HT2 agonists DOI, S-alpha-methyl-5-HT or MK212 had an additive effect on the plasma concentration of ACTH. The ACTH stimulating effect of each of the 5-HT agonists was inhibited by pretreatment with antagonists with corresponding 5-HT receptor affinity. The ACTH response to 5-HT or 5-HTP/Flx was inhibited by injection with the 5-HT1A+2A+2c+5A+7 antagonist methysergide, the 5-HT2A antagonist ketanserine and the 5-HT2C+2A antagonist LY 53857. The 5-HT1A antagonist WAY 100635 enhanced 5-HT- and 5-HTP/Flx-induced ACTH secretion, suggesting a presynaptic 5-HT1A autoreceptor effect of the drug. The 5-HT3 antagonist ondansetrone had no effect on the either of the 5-HT agonists. The 5-HT3+4 antagonist tropisetrone attenuated the effect of 5-HTP/Flx, which may suggest a stimulation of ACTH secretion via 5-HT4 receptors. It is concluded that 5-HT1A, 5-HT2A+2C, and to a lesser extent 5-HT1B receptors, but not 5-HT3 receptors are involved in the effects of serotonin agonists on ACTH secretion. Furthermore, an involvement of the 5-HT5A and the 5-HT7 receptor is possible.
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PMID:Adrenocorticotropic hormone secretion in rats induced by stimulation with serotonergic compounds. hsj@mfi.ku.dk. 1022 82

We examined the influence of imipramine and lithium on wet-dog shakes induced by the (+/-)-DOI, 5-HT2A receptor agonist in adrenocorticotropic hormone (ACTH)-treated rats. The administration of imipramine for 14 days decreased the (+/-)-DOI-induced wet-dog shakes response; chronic administration of lithium for 14 days, however, had no effect. Chronic ACTH (100 microg/rat sc) treatment increased the wet-dog shake response induced by (+/-)-DOI. This effect of ACTH for 14 days, increasing the (+/-)-DOI-induced wet-dog shakes, was not inhibited by a 14-day administration of imipramine. Chronic coadministration of imipramine and lithium, lasting 14 days, decreased the wet-dog shakes response induced by (+/-)-DOI in rats treated with ACTH for 14 days. These findings indicate that lithium inhibits the hyperfunction of the 5-HT2A receptor in rats treated with ACTH when coadministered with imipramine.
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PMID:Effects of imipramine and lithium on wet-dog shakes mediated by the 5-HT2A receptor in ACTH-treated rats. 1190 Aug 11

We previously reported the presence of serotonin (5-HT) in testes from golden hamster, a photoperiodic species which is a useful model for the study of states of male (in)fertility. The aims of this study were to investigate: (1) the presence of intrinsic sources of 5-HT in the testis; (2) the role of 5-HT in in vitro androgen production; (3) the serotoninergic receptor subtypes in the testis, and (4) the existence of interactions among the 5-HT receptors and the testicular catecholaminergic and corticotropin-releasing hormone (CRH) systems. Immunohistochemical studies revealed the presence of tryptophan hydroxylase, a 5-HT-biosynthetic enzyme, in interstitial cells which show the characteristic punctate chromatin pattern of Leydig cells. We describe an inhibitory action of 5-HT on testosterone, dihydrotestosterone, and androstane-3alpha,17beta-diol production from testes of peripubertal and adult hamsters maintained in a long photoperiod (14/10 h light/dark), and adult animals exposed to a short photoperiod (6/18 h light/dark). By using several agonists and antagonists of 5-HT receptors, we characterized 5-HT1A and 5-HT2A receptor subtypes involved in the inhibitory action of this neurotransmitter on human chorionic gonadotropin stimulated cyclic adenosine monophosphate and testosterone production. CRH also produced a negative modulation of both parameters, but epinephrine and norepinephrine, through alpha1/beta1-adrenergic receptors, exerted a stimulatory action. 5-HT1A, 5-HT2, and CRH antagonists showed that the testicular activity of the serotoninergic system, but also the alpha1/beta1-adrenergic receptor system, is mediated by CRH. Moreover, interactions between the 5-HT2A receptor system and alpha1/beta-adrenergic receptors have been established. Thus, these data suggest that alpha1/beta1-adrenergic receptors are involved in the local regulatory action exerted by 5-HT on steroidogenesis through a 5-HT2-receptor-mediated response and the CRH system.
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PMID:Interactions between testicular serotoninergic, catecholaminergic, and corticotropin-releasing hormone systems modulating cAMP and testosterone production in the golden hamster. 1209 15

The neurotransmitter serotonin (5-HT) stimulates adrenocorticotropic hormone (ACTH) secretion from the anterior pituitary gland via activation of central 5-HT1 and 5-HT2 receptors. The effect of 5-HT is predominantly indirect and may be mediated via release of hypothalamic corticotropin-releasing hormone (CRH). We therefore investigated the possible involvement of CRH in the serotonergic stimulation of ACTH secretion in male rats. Increased neuronal 5-HT content induced by systemic administration of the precursor 5-hydroxytryptophan (5-HTP) in combination with the 5-HT reuptake inhibitor fluoxetine raised CRH mRNA expression in the paraventricular nucleus (PVN) by 64%, increased pro-opiomelanocortin (POMC) mRNA in the anterior pituitary lobe by 17% and stimulated ACTH secretion five-fold. Central administration of 5-HT agonists specific to 5-HT1A, 5-HT1B, 5-HT2A or 5-HT2C receptors increased CRH mRNA in the PVN by 15-50%, POMC mRNA in the anterior pituitary by 15-27% and ACTH secretion three- to five-fold, whereas a specific 5-HT3 agonist had no effect. Systemic administration of a specific anti-CRH antiserum inhibited the ACTH response to 5-HTP and fluoxetine and prevented the 5-HTP and fluoxetine-induced POMC mRNA response in the anterior pituitary lobe. Central or systemic infusion of 5-HT increased ACTH secretion seven- and eight-fold, respectively. Systemic pretreatment with the anti-CRH antiserum reduced the ACTH responses to 5-HT by 80% and 64%, respectively. It is concluded that 5-HT via activation of 5-HT1A, 5-HT2A, 5-HT2C and possibly also 5-HT1B receptors increases the synthesis of CRH in the PVN and POMC in the anterior pituitary lobe, which results in increased ACTH secretion. Furthermore, the results indicate that CRH is an important mediator of the ACTH response to 5-HT.
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PMID:Serotonergic stimulation of corticotropin-releasing hormone and pro-opiomelanocortin gene expression. 1237 3

The neurotransmitter serotonin (5-HT) stimulates the secretion of vasopressin and oxytocin, and 5-HT is involved in the mediation of the vasopressin and oxytocin response to stress. In male Wistar rats, we investigated the 5-HT receptors involved in the 5-HT-induced increase of mRNA expression of vasopressin and oxytocin in the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON). The 5-HT precursor, 5-hydroxytryptophan, injected in combination with the 5-HT reuptake inhibitor, fluoxetine, increased oxytocin mRNA expression in the PVN, and the concentration of vasopressin and oxytocin in plasma, whereas mRNA in the SON was not affected. Intracerebroventricular infusion of 5-HT agonists selective for the 5-HT1A, 5-HT1B, 5-HT2A and 5-HT2C receptor increased oxytocin mRNA in the SON and PVN. Infusion of agonists selective for the 5-HT2A + 2C receptor increased vasopressin mRNA in the PVN, whereas none of the 5-HT agonists affected vasopressin mRNA in the SON. All the 5-HT agonists infused increased peripheral oxytocin concentration and vasopressin was increased by stimulation of the 5-HT2A, 5-HT2C and 5-HT3 receptor. Intracerebroventricular infusion of 100 nmol 5-HT increased the extracellular hypothalamic concentration of vasopressin as measured by microdialysis in the PVN. To evaluate the involvement of hypothalamic-pituitary system in the 5-hydroxytryptophan and fluoxetine-induced vasopressin secretion, rats were immunoneutralized with a specific anti-corticotropin-releasing hormone antiserum. This treatment reduced plasma vasopressin and oxytocin responses. We conclude that stimulation with 5-hydroxytryptophan or 5-HT agonists increases mRNA expression of oxytocin in the PVN and the SON via stimulation of at least 5-HT1A, 5-HT1B, 5-HT2A and 5-HT2C receptors. Vasopressin mRNA in the PVN was increased only via the 5-HT2 receptor, whereas vasopressin mRNA in the SON does not seem to be affected by 5-HT stimulation. Corticotropin-releasing hormone appears to be partly involved in the mediation of 5-HT induced vasopressin and oxytocin secretion.
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PMID:Serotonin stimulates hypothalamic mRNA expression and local release of neurohypophysial peptides. 1271 7

Differential adaptive changes in serotonin2A [5-hydroxytryptamine (5-HT)2A] receptor signaling during treatment may be one mechanism involved in the latency of therapeutic improvement with antidepressants, such as fluoxetine. We examined the effects of fluoxetine (2, 3, 7, 21, or 42 days) on hypothalamic 5-HT2A receptor signaling. The hormone responses to an injection of the 5-HT2A receptor agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane HCl (DOI) were used as an index of hypothalamic 5-HT2A receptor function. Treatment with fluoxetine for 21 or 42 days produced diminished adrenocorticotropic hormone (ACTH) and oxytocin (but not corticosterone) responses to DOI injections (2.5 mg/kg i.p.; 15 min postinjection). Regulators of G protein signaling 4 and Galphaq protein levels in the hypothalamic paraventricular nucleus were not altered during fluoxetine treatment. Because previous studies indicate that treatment with fluoxetine for 21 days resulted in increased hormone responses to DOI when measured at 30 min after injection, we examined the effect of fluoxetine (21 days) on DOI-induced increase hormone levels at 15, 30, and 60 min after DOI injection. Fluoxetine decreased the oxytocin response at 15 but not at 30 min post-DOI injection, and potentiated the ACTH and corticosterone responses at 30 min post-DOI injection. For comparison, we examined the effect of fluoxetine on 5-HT2A receptor-mediated increase in phospholipase C (PLC) activity in the frontal cortex. 5-HT-stimulated, but not guanosine 5'-O-(3-thio)triphosphate-stimulated PLC activity was increased after 21 days of fluoxetine-treatment. Overall, these results indicate that chronic fluoxetine treatment can potentiate 5-HT2A receptor signaling in frontal cortex but differentially alters 5-HT2A receptor signaling in oxytocin-containing neurons and corticotropin-releasing factor-containing neurons in the paraventricular nucleus.
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PMID:Chronic fluoxetine differentially affects 5-hydroxytryptamine (2A) receptor signaling in frontal cortex, oxytocin- and corticotropin-releasing factor-containing neurons in rat paraventricular nucleus. 1272 28

Serotonin (5-hydroxytryptamine, 5-HT)-containing neurons in the midbrain directly innervate corticotropin-releasing hormone (CRH)-containing cells located in paraventricular nucleus of the hypothalamus. Serotonergic inputs into the paraventricular nucleus mediate the release of CRH, leading to the release of adrenocorticotropin, which triggers glucocorticoid secretion from the adrenal cortex. 5-HT1A and 5-HT2A receptors are the main receptors mediating the serotonergic stimulation of the hypothalamic-pituitary-adrenal axis. In turn, both CRH and glucocorticoids have multiple and complex effects on the serotonergic neurons. Therefore, these two systems are interwoven and communicate closely. The intimate relationship between serotonin and the hypothalamic-pituitary-adrenal axis is of great importance in normal physiology such as circadian rhythm and stress, as well as pathophysiological disorders such as depression, anxiety, eating disorders, and chronic fatigue.
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PMID:Serotonin and the neuroendocrine regulation of the hypothalamic--pituitary-adrenal axis in health and disease. 1285 56


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