Dehydroepiandrosterone does not prevent adrenocorticotrophin-induced hypertension in conscious rats

1. We tested the hypothesis that dehydroepiandrosterone (DHEA), which prevents dexamethasone-induced hypertension in rats, may block adrenocorticotrophin (ACTH) hypertension, which has been presumed due to corticosterone excess. The blood pressure and metabolic effects of DHEA (18 mg/kg per day) were examined in sham and ACTH-treated (0.5 mg/kg per day) conscious Sprague-Dawley rates (n = 20). 2. ACTH but not sham injection increased blood pressure, water intake and urine output and decreased bodyweight. 3. DHEA administration for 10 days did not alter blood pressure or metabolic effects in either sham or ACTH-treated rats. 4. DHEA, which is known to block dexamethasone-induced hypertension, did not modify ACTH-induced hypertension in the rat. This suggests either that ACTH-induced hypertension is not simply a consequence of glucocorticoid activity or that the action of DHEA in dexamethasone hypertension is not through blocking the glucocorticoid receptor.