Abstract
In primary 2-day cultured bovine adrenocortical cells, adrenaline stimulated the steroidogenesis, while the effect of adrenaline did not appear in the freshly isolated cells. Thus the primary 2-day cultured cells were used to study the effect of adrenaline on steroidogenesis. Adrenaline showed the steroidogenesis-stimulating effect at concentrations higher than 10-9 M, and the maximum effect was obtained between 10-6 M and 10-5 M in the primary 2-day cultured cells. The maximum effect of adrenaline was 50-70% of that of adrenocorticotropic hormone (ACTH). Noradrenaline, isoproterenol and phenylephrine also stimulated the steroidogenesis. However, the order of the potency was isoproterenol >> adrenaline =noradrenaline >>> phenylephrine. Propranolol and alprenolol inhibited the effect of adrenaline, but phenoxybenzamine and phentolamine did not inhibit the effect. Moreover, adrenaline stimulated the cyclic AMP production dose-dependently at concentrations higher than 10-8 M. These results suggest that there are steroidogenesis-linked adrenergic receptors in primary 2-day cultured bovine adrenocortical cell membrane and that the steroidogenesis-stimulating effect of adrenaline occurs through the β-adrenergic receptor.
