Biochemical evidence for peripheral neural regulation of adrenocortical regeneration in response to bilateral adrenal enucleation

Male sprague-Dawley rats (130–150 g) with bilateral adrenal enucleation were used in this study. Animals were sacrificed at 2, 7, and 11 days post enucleation and plasma corticosterone and adrenal gland acetylcholin-esterase (AChE), choline acetyltransferase (ChAT), corticosterone, epinephrine (EP) and norepinephrine (NE) were assayed. The results show a progressive and gradual increase in plasma and adrenal corticosterone levels, AChE, ChAT, EP, and NE levels in the regenerating adrenal cortex from day 2 to day 11 post bilateral adrenal enucleation. At day 11 post surgery, the activities of ChAT and AChE were 60% and 25%, respectively when compared to sham operated control. The EP and NE levels returned to normal levels after 11 days post surgery in the regenerating gland when compared to the sham control. The presence of both cholinergic enzymes and the availability of high levels of catecholamine strongly suggest a progressive development of sympathetic innervation in the regenerating adrenal cortex.