Effects of unilateral adrenalectomy on the remaining adrenal cortex of adrenocorticotropic hormone-treated male and female hamsters

Sham-operated and unilaterally adrenalectomized male and female hamsters were administered 25 micrograms adrenocorticotropic hormone (ACTH) for 5 days after the operation in order to examine the effects of ACTH on compensatory adrenal growth. In ACTH-treated male and female hamsters, unilateral adrenalectomy did not change the relative weight of the remaining adrenal. There were no significant differences in the volumes of the adrenocortical zones and their parenchymal cells, as well as in the number of adrenocortical cells per gland if compared with unilaterally adrenalectomized and sham-operated ACTH-treated male hamsters, while 3H-thymidine incorporation per gland was lower in monoadrenalectomized animals. On the contrary, in ACTH-treated females, unilateral adrenalectomy resulted in a significant hypertrophy of zona fasciculata cells and in an enhanced 3H-thymidine uptake by the remaining gland. These findings stress the existence of notable sex-related differences in the compensatory adrenal growth in hamsters.