The histopathology and biochemistry of rats bearing an adrenocortical tumor.

An adrenocortical tumor originating in a female Osborne-Mendel rat was trans planted to intact and adrenalectomized males and to female rats of the same strain. The transplanted tumor grew best in intact males, less in intact females, and least in adrenalectomized males. The following changes characterized the animals bearing this tumor: atrophy of zona fasciculate and zona reticularis of the adrenal cortex; a sharp reduction in urinary sodium excretion, both in intact and adrenalectomized rats; in creased urinary potassium excretion; hypernatremia and hypokalemia. These findings suggest mineralocorticoid secretion by this tumor. Atrophy of the vagina and uterus, and anestrus are among the nonspecific changes due to the presence of the tumor. Polyuria in these rats and its relief with pituitrin may indicate pituitary dysfunction.