Effect of selenium (Se) on plasma ACTH, beta-endorphin, corticosterone and glucose in rat: influence of adrenal enucleation and metyrapone pretreatment.
The effects of acute treatment (i.p.) with selenium (Se) on glucoregulation, by measuring plasma levels of adrenocorticotropic hormone (ACTH), beta-endorphin (beta-EN), corticosterone (CORT) and glucose over time, were investigated. The hormones of the hypothalamic-pituitary adrenal (HPA) axis, were measured after treating rats with saline, Se: 1.6 mg/kg, or 3.8 mg/kg. Blood samples were collected before, 30, 60 and 90 min following injection. The results show that i.p. administration of Se (both doses) induce a rise in plasma ACTH, and beta-EN (P < 0.01). Plasma CORT and glucose levels also rose sharply by 30 min (P < 0.05). Corticosterone levels were increased in a dose-dependent fashion over the ensuing hour. Bilateral adrenal demedullation resulted in the abolishment of the Se-induced rise in plasma glucose. Pretreatment with metyrapone (300 mg/kg) was found to delay the Se-induced rise in plasma glucose. The results indicate that after a Se challenge the HPA axis is activated. In addition, CORT was found to be essential in the Se-induced rise in plasma glucose.
Potmis
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Florida Agricultural and Mechanical University, College of Pharmacy and Pharmaceutical Sciences, Tallahassee 32307.
Nonavinakere
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Rasekh
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Early
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JL
D000313:Adrenal Medulla / Q000502:physiology; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D003345:Corticosterone / Q000097:blood*; D008297:Male; D008797:Metyrapone / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012643:Selenium / Q000494:pharmacology*; D001615:beta-Endorphin / Q000097:blood*
D001786:Blood Glucose; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D012643:Selenium; D003345:Corticosterone; D008797:Metyrapone