Effects of ACTH on adrenocortical cells autotransplanted in the rat spleen: ultrastructural and morphometric observations.

The effects of chronic ACTH administration on adrenocortical cells autotransplanted in the rat spleen have been investigated. Morphometry showed that ACTH induced a significant hypertrophy of adrenocortical cells, which was mainly due to the increase in the smooth endoplasmic reticulum and mitochondrial compartment. Competitive protein binding assay demonstrated that adrenocortical cell hypertrophy was associated with a two-fold rise in the plasma corticosterone concentration. These data indicate that autotransplanted adrenocortical cells are normally sensitive to ACTH, which enhances their growth and steroidogenic capacity.