Transcription of (pro)renin mRNA in the rat adrenal cortex, and the effects of ACTH treatment and a low sodium diet

Transcription of the (pro)renin gene in the adult rat adrenal gland was studied by non-isotopic in situ hybridization. In glands from control (untreated) animals, transcription was relatively sparse, and occurred mostly in the outer zona fasciculata. Treatment with ACTH increased the apparent signal in both the glomerulosa and in fasciculata zones. A low sodium diet initially enhanced the transcription signal specifically in the glomerulosa, but as the regime was extended from 5 days to more than 2 weeks, the signal was also increased dramatically in the zona reticularis. The results emphasize the potential importance of the intraglandular renin-angiotensin system, particularly under conditions of chronic stimulation. They also suggest that angiotensin II, as well as being the major regulator of the glomerulosa, may also have some role in inner adrenocortical zone functions.