TRANSCRIPTION OF (PRO)RENIN MESSENGER-RNA 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 wa s studied by non-isotopic ill situ hybridization. In glands from contr ol (untreated) animals, transcription was relatively sparse, and occur red mostly in the outer zona fasciculata. Treatment with ACTH increase d the apparent signal in both the glomerulosa and in fasciculata zones . A low sodium diet initially enhanced the transcription signal specif ically in the glomerulosa, but as the regime was extended from 5 days to more than 2 weeks, the signal was also increased dramatically in th e zona reticularis. The results emphasize the potential importance of the intraglandular renin-angiotensin system, particularly under condit ions of chronic stimulation. They also suggest that angiotensin II, as well as being the major regulator of the glomerulosa, may also have s ome role in inner adrenocortical zone functions.