Characterization of the steroidogenic responsiveness and ultrastructure of purified zona fasciculata/reticularis cells from bovine adrenal cortex before and after primary culture.

Analysis by electron microscopy indicated that after 3 days of primary culture, purified bovine adrenal zonal fasciculata/reticularis (ZF/ZR) cells showed improved integrity of their ultrastructure, with an increased density of lipid droplets and smooth endoplasmic reticulum. The basal cortisol output was significantly (P less than 0.05) greater on day 3 of culture than for the freshly isolated cells in six out of seven experiments. Similarly, in six experiments with ACTH (1 nmol/l) and five experiments with angiotensin II (10 nmol/l), the stimulated cortisol secretion was significantly (P less than 0.01 for all 11 experiments) higher on day 3 of culture than in freshly isolated cells. No significant increase in cortisol secretion above basal was observed with noradrenaline at any concentration in the freshly isolated cells, whereas a dose-dependent increase in cortisol secretion was observed on day 3 of culture in all of four experiments. These findings were supported by cyclic (c) AMP output measured in one such experiment. Thus the basal cAMP output and that stimulated by ACTH (1 nmol/l) were significantly higher after culture (P less than 0.001, n = five wells for basal comparison; P less than 0.05, n = three wells for ACTH at 1 nmol/l). In agreement with the cortisol results, cAMP production was unaffected by any concentration of noradrenaline in the freshly isolated cells, whereas a dose-dependent rise was found after culture. Angiotensin II at all concentrations had no effect on cAMP production in freshly isolated or cultured cells.(ABSTRACT TRUNCATED AT 250 WORDS)