Masahiro Kawamura1,*, Akiyoshi Niitsu2, Haruhisa Nishi1 and Eiji Masaki1
1Department of Pharmacology (I), and 2Department of Internal Medicine, Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
*Corresponding author. FAX: +81-3-5473-1428, E-mail: jkyakuri@sepia.ocn.ne.jp
Abstract: We examined the effect of extracellular adenosine 5'-triphosphate (ATP) on adrenocorticotropic hormone (ACTH)- and angiotensin II-induced steroidogenesis in bovine adrenocortical fasciculata cells. The low concentration of ATP (5 μM) potentiated ACTH-induced steroidogenesis synergistically. However, the purine derivative did not affect angiotensin II-induced steroidogenesis. Although adenosine (100 μM) (a metabolite of ATP) showed a weak steroidogenic effect, it did not potentiate ACTH-induced steroidogenesis. ATP also enhanced the steroidogenesis by NaF synergistically in bovine adrenocortical cells, but did not potentiate forskolin- and dibutyryl cyclic AMP-induced steroidogenesis. The stimulating effect of ACTH on cyclic AMP production was synergistically accelerated by ATP (5 μM), which has no effect by itself on cyclic AMP formation. These results suggest that extracellular ATP affected the ACTH receptor-adenylyl cyclase coupling processes, and potentiation of steroidogenesis by ACTH ensued in bovine adrenocortical fasciculata cells.
Keywords: Adrenal cortex, Adrenocorticotropic hormone, Steroidogenesis, ATP, P2Y receptor
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