Abstract
Effect of ACTH administration on the rate of phospholipid exchange in vitro between rat adrenal microsomes and mitochondria was examined using 3H-cholinelabeled adrenal microsomes as the donor of phospholipids. Increased rate of exchange was observed between control microsomes and mitochondria isolated from rats received 6 u. of ACTH 3.5 hr before death of the animals. On the contrary, mitochondria obtained from the animals treated with ACTH for consecutive 3 days exhibited less capacity of the exchange. The almost identical results were obtained when the microsomes obtained from ACTH-treated animals were used as the donor of phospholipids. Attempts for the exchange of phospholipid in vitro between inner and outer membranes of adrenal mitochondria and between microsomes and inner membrane of mitochondria were unsuccessful.
