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)

The 5-HT receptor agonists, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) produced dose-dependent increases in plasma adrenocorticotropin (ACTH) in the male rat by activation of 5-HT1A and 5-HT2 receptors respectively. The ACTH response to DOI was enhanced by repeated administration of electroconvulsive shock (five over 10 days) but abolished by the tricyclic antidepressant, amitriptyline (20 mg/kg for 14 days). In contrast 21 days lithium treatment failed to alter DOI-induced ACTH release. Neither repeated electroconvulsive shock, nor amitriptyline, nor lithium altered the ACTH response to 8-OH-DPAT. These data are consistent with results from ligand binding and behavioural studies which suggest that the sensitivity of brain 5-HT2 receptors is increased by repeated electroconvulsive shock but attenuated by tricyclic antidepressant treatment. In contrast, our data suggest that the antidepressant treatments studied do not alter the sensitivity of the 5-HT1A receptors involved in ACTH release.
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PMID:Selective 5-HT1A and 5-HT2 receptor-mediated adrenocorticotropin release in the rat: effect of repeated antidepressant treatments. 133 74

To explore 5-HT1A receptor responsivity in panic disorder (PD), hypothermic, neuroendocrine and behavioral responses to the selective partial 5-HT1A receptor agonist ipsapirone (IPS) were investigated in patients with primary PD and healthy controls. Fourteen patients and matched controls received a single oral dose of 0.3 mg/kg IPS or placebo under double-blind, random-assignment conditions. IPS induced hypothermia and corticotropin (ACTH)/cortisol release but had only minimal effects on behavior. Compared with controls, the patients with PD exhibited significantly attenuated thermoregulatory and neuroendocrine responses to IPS. Although the healthy subjects reported increased drowsiness and the PD patients rated themselves more nervous and less calm following administration of IPS, no consistent changes in ratings of anxiety or panic symptoms were recorded. The impaired hypothermic and ACTH/cortisol responses following 5-HT1A receptor activation reflects subsensitivity of both the pre- and post-synaptic 5-HT1A receptor-effector system, thus supporting the hypothesis that a 5-HT1A receptor-related serotonergic dysfunction may be linked to the pathophysiology of PD. Future studies of 5-HT1A receptor-effector complex function in conjunction with assessment of the responsivity of other subtypes (e.g. 5-HT2, 5-HT3) should promote the evaluation of 5-HT system integrity in anxiety disorders and its involvement in anxiolytic drug effects.
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PMID:5-HT1A receptor-effector system responsivity in panic disorder. 134 19

We investigated the hypothesis that cocaine-induced elevations of plasma adrenocorticotropin hormone (ACTH) and corticosterone are mediated by brain serotonin (5-HT) neurons. Adult male rats were pretreated with the 5-HT depleting agent p-chlorophenylalanine, the 5-HT neurotoxin 5,7-dihydroxytryptamine, the partial 5-HT1A agonist 8-(2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl)-8- azaspirol[4,5]-decane-7,9-dione (BMY 7378) or the 5-HT1C/2 antagonist ritanserin. The effects of cocaine (2-15 mg/kg, i.p.) on plasma ACTH and corticosterone were then examined. Cocaine dose-dependently increased ACTH and corticosterone concentration. This increase was prevented by 5-HT depletion with PCPA and by destruction of 5-HT neurons with i.c.v. injections of 5,7-dihydroxytryptamine. The cocaine-induced elevation of ACTH and corticosterone was not significantly modified by administration of the partial 5-HT1A agonist BMY 7378, suggesting that 5-HT1A receptors probably do not mediate ACTH and corticosterone secretion. However, pretreatment with the 5-HT2/5-HT1C antagonist ritanserin virtually eliminated the cocaine-induced elevation of corticosterone. To determine whether these effects of cocaine are centrally mediated, conscious rats received cocaine injections into the cerebral ventricle through chronically implanted cannulas. Plasma ACTH concentrations were dose-dependently increased, whereas low doses (50 micrograms/kg, i.c.v.) produced a maximal increase in corticosterone concentration. These data indicate that the cocaine-induced stimulation of ACTH and corticosterone secretion is mediated by 5-HT neurons in brain, and furthermore, that 5-HT2 or 5-HT1C receptors are responsible for this effect.
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PMID:Cocaine-induced elevation of plasma adrenocorticotropin hormone and corticosterone is mediated by serotonergic neurons. 165

The effect of lithium administration (800 mg daily for 7 days) on the neuroendocrine and temperature responses to the 5-HT1A receptor agonist, gepirone, was studied in eight healthy male volunteers. Gepirone (20 mg orally) significantly increased plasma levels of prolactin, growth hormone, corticotropin and cortisol, and lowered oral temperature. None of these responses was significantly altered by lithium treatment. The results suggest that the ability of short-term lithium treatment to increase 5-HT-mediated neuroendocrine responses in humans is unlikely to be related to changes in the sensitivity of pre- or post-synaptic 5-HT1A receptors.
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PMID:Lithium and 5-HT1A receptor sensitivity: a neuroendocrine study in healthy volunteers. 166 54

1. Azapirones, selective partial agonists at the 5-HT1A receptor subtype, induce hypothermia and corticotropin (ACTH)/cortisol release as specific functional correlates of central 5-HT1A receptor activation. 2. Compared to controls, hypothermic and ACTH/cortisol responses to the azapirone ipsapirone are attenuated in patients with unipolar depression and panic disorder but not in patients with obsessive-compulsive disorder. The impaired thermic and neuroendocrine responses are associated with increased basal cortisol secretion in depressed patients but not in patients with panic disorder. 3. Chronic treatment with the selective 5-HT reuptake inhibitor fluoxetine decreases 5-HT1A receptor-mediated responses in patients with obsessive-compulsive disorder, while long-term treatment with the tricyclic antidepressant amitriptyline further decreases hypothermia following ipsapirone but has no effect on ACTH/cortisol release. 4. Alteration of the 5-HT1A receptor and/or its signal transduction pathways may play a role in the pathophysiology and treatment of anxiety disorders and depression.
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PMID:5-HT1A receptor responsivity in anxiety disorders and depression. 176 90

The effects of MDL 73005EF (8-[2-(2,3-dihydro-1,4-benzodioxin-2-yl)methylamino]-8- azaspiro[4,5]decan-7,9-dione methyl sulphonate), a novel selective 5-HT1A receptor ligand with putative anxiolytic properties, were explored using models of central pre- and postsynaptic 5-HT1A receptor function in the male rat. MDL 73005EF dose dependently decreased the hippocampal 5-HT output measured by in vivo microdialysis in chloral hydrate-anaesthetised rats and this response was antagonised by the 5-HT1A/B receptor antagonist, pindolol. Local administration of MDL 73005EF had no effect on the hippocampal 5-HT output. MDL 73005EF failed to alter basal plasma adrenocorticotropin (ACTH) levels but, in common with pindolol, attenuated the ACTH response to the 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). In contrast to 8-OH-DPAT, MDL 73005EF significantly increased plasma prolactin but apparently not through a 5-HT receptor-mediated mechanism. The results indicate that MDL 73005EF possesses mixed 5-HT1A receptor agonist/antagonist properties, acting as an agonist at presynaptic 5-HT1A receptors controlling 5-HT release and as an antagonist at postsynaptic 5-HT1A receptors mediating ACTH release.
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PMID:Effects of MDL 73005EF on central pre- and postsynaptic 5-HT1A receptor function in the rat in vivo. 196 8

In healthy volunteers, the azapirones--buspirone, ipsapirone, and gepirone--increase plasma cortisol and decrease body temperature; buspirone and gepirone also increase plasma prolactin and growth hormone. Data from animal studies suggest that the ability of azapirones to decrease body temperature and increase corticotropin and corticosterone is mediated by stimulation of presynaptic and postsynaptic serotonin (5-hydroxytryptamine, 5-HT) type 1A subtype receptors, respectively. The mechanism of altered growth hormone and prolactin secretion is less clear. While animal studies implicate changes in dopamine function, current human investigations suggest that 5-HT1A receptors also may be involved in these endocrine responses. Further investigations, using more selective 5-HT receptor antagonists, will be required to resolve this issue.
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PMID:Neuroendocrine effects of azapirones. 197 37

The selective 5-HT1A receptor ligand ipsapirone (IPS) induces corticotropin (ACTH) and cortisol secretion in humans. To explore 5-HT1A receptor-mediated hypothalamic-pituitary-adrenal (HPA) system activation in depression, 24 subjects (12 patients with unipolar depression and 12 individually matched controls) were given 0.3 mg/kg IPS or placebo in random order. Compared with controls, the depressed patients exhibited significantly decreased ACTH and cortisol responses to IPS in association with increased basal cortisol secretion. The impaired HPA response following 5-HT1A receptor challenge in unipolar depression could have resulted from glucocorticoid-dependent subsensitivity of the (post-synaptic) 5-HT1A receptor itself and/or from a defective postreceptor signaling pathway [inhibitory guanine nucleotide-binding protein (Gi)-adenylate cyclase complex function], thus supporting the hypothesis that a disintegrated 5-HT and HPA system interaction may be present in depression. Future studies of the HPA response to direct-acting 5-HT1A ligands, such as IPS, should facilitate the assessment of 5-HT/HPA system integrity in various affective disorders and its involvement in psychotropic drug effects.
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PMID:5-HT1A receptor responsivity in unipolar depression. Evaluation of ipsapirone-induced ACTH and cortisol secretion in patients and controls. 197 79

Although (+/-) methylenedioxymethamphetamine (MDMA) has been reported to deplete serotonin (5-HT) and destroy 5-HT terminals in the brains of animals, the functional sequelae of such alterations remain to be established. In the present study, a blunted corticotropin and an enhanced prolactin response to the 5-HT1A agonist 8-hydroxy-2(di-n-propylamino)tetralin (8-OH DPAT) was found in rats treated two weeks previously with a single dose of MDMA (2.0 or 20.0 mg/kg, sc). These results suggest that neurochemical changes produced by MDMA are associated with functional alterations as manifested by abnormal 5-HT receptor-coupled neuroendocrine responses.
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PMID:Diminished corticotropin and enhanced prolactin responses to 8-hydroxy-2(di-n-propylamino)tetralin in methylenedioxymethamphetamine pretreated rats. 198 41

Activation of serotonergic neurotransmission has been shown to increase plasma beta-endorphin-like immunoreactivity (beta-End-LI). To study the mechanism(s) of this action, we measured the effects of 3 potent serotonin (5-HT) agonists with different structures and 5-HT receptor binding profiles in conscious unrestrained Sprague-Dawley rats in vivo and in dispersed anterior pituicytes in vitro. The 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), the 5-HT1C agonist, m-chlorophenylpiperazine (m-CPP), and the 5-HT2 agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), all markedly increased beta-End-LI in plasma in vivo. All 3 responses were blocked by dexamethasone pretreatment. Pituitary stalk transection (PST), as well as pretreatment with rabbit serum hyperimmune against rat corticotropin-releasing hormone (CRH, TS-6) completely abolished beta-End-LI response to 8-OH-DPAT and attenuated the responses by about 60% to DOI. Responses to m-CPP were markedly attenuated in PST rats, but pretreatment with TS-6 had no significant effect. To examine whether vasopressin (AVP) might be involved in the CRH neutralizing antibody-resistant beta-End-LI responses after m-CPP and DOI, we measured AVP concentrations after each agonist, m-CPP, but not DOI or 8-OH-DPAT, significantly elevated circulating AVP levels. As a proof of direct pituitary effect, DOI markedly stimulated beta-End-LI release from the anterior pituitary cell culture preparation in vitro. It was approximately as potent as CRH in the picomolar range, m-CPP was much less effective than DOI, while 8-OH-DPAT did not stimulate beta-End-LI release in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Beta-endorphin responses to different serotonin agonists: involvement of corticotropin-releasing hormone, vasopressin and direct pituitary action. 215 Jul 76


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