Expression of cytochrome P450 aldosterone synthase and 11 beta-hydroxylase mRNA during adrenal regeneration

In situ hybridization histochemistry was used to monitor the expression of cytochrome P450 aldosterone synthase (P450aldo) and cytochrome P450 11 beta-hydroxylase (P45011 beta) mRNA in regenerating rat adrenals. Comparisons were made between regenerating adrenals from unilateral enucleated/unilateral adrenalectomized (ULE/ULA) and bilateral enucleated (BLE) rats. During the first week after enucleation, P45011 beta mRNA was expressed in all adrenals reflecting the presence of fasciculata cells; however, P450aldo mRNA was detected only in adrenals from ULE/ULA rats suggesting that the glomerulosa cell phenotype was absent after BLE. These findings suggest that the expression of glomerulosa cells during the early period of regeneration is influenced by the presence of a second regenerating adrenal.