Suppressing effects of bisphenol A on the secretory function of ovine anterior pituitary cells.

We investigated the action of bisphenol A (BPA) on cellular GH release and content, cell number, GHmRNA expression, and concentrations of cellular cyclic AMP ([cAMP]c) and calcium ion ([Ca2+]c) in primary cultured ovine anterior pituitary cells. The following results were found: (1) BPA as well as nonylphenol (NP) at 10(-6) to 10(-3) M significantly and concentration-dependently suppressed basal and GHRH-stimulated GH release, and the cellular GH content, (2) BPA suppressed the cell number in a time- and concentration-dependent manner, (3) 10(-4)M BPA suppressed GHmRNA expression to 68% of control (BPA-free), and abolished GHRH (10(-8) M)-induced increases in [cAMP]c and [Ca2+]c. From these findings we conclude that BPA possesses a suppressing action on GH synthesis and release, and this suppressing action is probably related to impairment of cellular signal transduction systems in ovine anterior pituitary cells.