Biol. Pharm. Bull., 31(6),1205-1208, June 2008

Regular Articles

Effects of Pantothenic Acid Supplementation on Adrenal Steroid Secretion from Male Rats

Sukanya JAROENPORN,a,b Tatsuya YAMAMOTO,a,b Asuka ITABASHI,b Katsuhiro NAKAMURA,c Isao AZUMANO,c Gen WATANABE,a,b and Kazuyoshi TAYA*,a,b

a Department of Basic Veterinary Science, The United School of Veterinary Sciences, Gifu University; Gifu 501-1193, Japan: b Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology; Tokyo 183-8509, Japan: and c Daiichi Fine Chemical Co.; Tokyo 103-0025, Japan. * To whom correspondence should be addressed.

The effects of pantothenic acid-supplementation on the adrenal secretion of corticosterone and progesterone in male rats were investigated using an in vitro cell culture system. Male rats at 21 d of age were given 0.03% pantothenic acid in their drinking water for 9 weeks. After 9 weeks of treatment, the animals were decapitated, and adrenal cells were cultured in the absence or presence of rat adrenocorticotropic hormone (ACTH; 10−15 to 10−10 M) and/or ovine prolactin (oPRL; 10−9 to 10−7 M) for 4 h. Adrenal cells in pantothenic acid-treated rats exhibited higher basal levels of corticosterone and progesterone than control rats. The response of ACTH and/or PRL on corticosterone and progesterone release was higher in the pantothenic acid-treated rats than in the control rats. In addition, PRL increased the stimulatory effect of ACTH-induced corticosterone secretion in both normal and pantothenic acid-treated rats. These results clearly demonstrated that pantothenic acid supplementation stimulates the ability of adrenal cells in male rats to secrete corticosterone and progesterone. Additionally, these results also showed that pantothenic acid supplementation induced adrenal hyperresponsiveness to ACTH stimulation, and PRL further stimulated adrenal sensitivity to ACTH.

Key words adrenal gland; corticosterone; pantothenic acid; rat