A high dose of vitamin E inhibits adrenal corticosterone synthesis in chickens treated with ACTH.
The present experiment was conducted to study the effects of dietary vitamin E on plasma corticosterone (CTC) concentration and adrenal steroid syntheses in chickens treated with adrenocorticotropic hormone (ACTH). Chickens were divided into ACTH(-) and ACTH(+) groups, and each group was further divided into three subgroups administered with vitamin E (500 or 5,000 mg/kg diet) and without the vitamin. Vitamin E (DL-alpha-tocopheryl acetate) was mixed with the basal diet at levels of 500 and 5,000 mg/kg and fed for 6 d. ACTH (20 IU/kg body weight) was given daily by intraperitoneal injection for 5 d. alpha-Tocopherol levels in the plasma and adrenal gland were markedly elevated by vitamin E feeding, and the level of adrenal free cholesterol (CHOL), which is used for steroid synthesis, was significantly decreased by vitamin E feeding in a dose-dependent manner. However, the level of adrenal CHOL ester was unchanged by any treatment. The elevations of pregnenolone, progesterone and CTC levels in the adrenal gland of chickens with ACTH treatment were decreased by vitamin E administration. The elevation of plasma CTC concentration in the ACTH(+) group was dramatically decreased by vitamin E administration, while that concentration was not influenced by the vitamin administration in the ACTH(-) group. These findings indicate that vitamin E suppresses the elevation of the plasma CTC concentration due to ACTH in chickens, possibly by inhibiting the conversion of CHOL ester to free CHOL in the adrenal gland.
Taniguchi
N
N
Faculty of Agriculture, Kagoshima University, Japan.
Ohtsuka
A
A
Hayashi
K
K
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage*; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D002645:Chickens; D002784:Cholesterol / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D003345:Corticosterone / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000097:blood; D003350:Cortodoxone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D011284:Pregnenolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
D000975:Antioxidants; D014810:Vitamin E; D011374:Progesterone; D011284:Pregnenolone; D000324:Adrenocorticotropic Hormone; D002784:Cholesterol; D003345:Corticosterone; D003350:Cortodoxone