Similar Response of Spontaneously Hypertensive and Normotensive Rats to Adrenal Enucleation 1

Summary Spontaneously hypertensive rats (SHR) and normal Wistar rats were subjected to right adrenalectomy and enucleation of the left adrenal. Both types of animal responded to this procedure in similar manner. The blood pressure fell during the initial interval of adrenal insufficiency and then rebounded during adrenal regeneration to substantially higher levels than the preoperative. Slightly more than half the normal rats were rendered hypertensive by adrenal enucleation. Plasma corticosterone declined shortly after enucleation and then rose progressively to normal levels in the course of adrenal regeneration. Three months after enucleation the adrenals of both groups of animals were similar in weight and also in gross and microscopic appearance. In the parameters of function and structure studied, the regenerating adrenal cortical cells of SHR showed no distinct difference from the corresponding cells of the progenitor strain. In both the SHR and the normal Wistar rats the regenerating adrenal either provided the milieu which permitted hypertension to develop or caused the high blood pressure through hypersecretion or abnormal secretion of steroids.