Do ACTH, angiotensins I and II, increased potassium, and decreased sodium concentrations stimulate steroidogenesis and alter cyclic AMP levels in beef adrenal tissue slices?
This preclinical study demonstrates that ACTH and potassium stimulate adrenal steroidogenesis via cyclic AMP, whereas angiotensin I and II utilize a different mechanism, and decreased sodium acts at a later step in the biosynthetic pathway.
The effects of adrenocorticotropin (ACTH), angiotensins I and II, increased potassium, and decreased sodium concentrations upon steroid synthesis were examined by incubation of beef adrenal tissue slices. Angiotensin II shared with ACTH the need for calcium and an inhibition of its effect in the presence of puromycin but differed in not stimulating cyclic adenosine monophosphate (AMP). Angiotensin I was effective in steroidogenesis. The stimulation of aldosterone synthesis by increased potassium concentration was accompanied by an increased level of cyclic AMP and was inhibited in the presence of puromycin. Decreased sodium concentration stimulated aldosterone synthesis but, alone of these stimuli, simultaneously decreased corticosterone levels. It therefore appears that ACTH and potassium stimulate steroidogenesis at an early step in the biosynthetic pathway through the activation of cyclic AMP, whereas the effect of angiotensins I and II involve another mechanism and decreased sodium concentration affects a later step in steroidogenesis.
Saruta et al. (Fri,) studied this question.