The Histopathology and Biochemistry of Rats Bearing an Adrenocortical ]hmor

An adrenocortical tumor originating in a female Osborne-Mendel rat was transplanted 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 fasciculata and zona reticularis of the adrenal cortex; a sharp reduction in urinary sodium excretion, both in intact and adrenalectomized rats; increased 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.