The main intention of this study was to examine the effect of cyclic somatostatin (SRIF) on bovine adrenal cell activity in vitro. beta-Endorphin was applied in another course of experiments. Basal aldosterone secretion when measured was found to be 0.86 +/- 0.33 ng per 10(5) cells and 1.5 h incubation time in the glomerulosa cell fractions. Cortisol production was 1.6 +/- 0.3 ng per 10(5) cells in the fasciculata/reticularis cell incubates respectively. No effect was observed when cyclic somatostatin (SRIF) was added to cell incubates of the bovine adrenal cortex. However, aldosterone secretion was increased 4.5-fold in the presence of 10(-9)M ACTH or 10(-8)M At II. Cortisol production was enhanced similarly after addition of 10(-9)M ACTH.