Extirpation of Pituitary Gland on Arterial Blood Pressure of Dogs with Experimental Hypertension

Abstract

The introduction by Goldblatt, Lynch, Hanzal and Summerville 1 of a reliable method by which hypertension can be produced in dogs has opened an avenue of approach of great importance to study of experimental hypertension. It consists in producing renal ischemia by means of adjustable silver clamps applied to the renal arteries.

Since the pituitary gland has been thought by some observers, notably Cushing, 2 to be involved in the genesis of hypertension in man, we have sought to find whether it also is associated in the genesis of hypertension produced by the method of Goldblatt, Lynch, Hanzal and Summerville.

Blood pressure measurements were made according to the method of Van Leersum. Arterial pressure was measured usually daily until it seemed certain that the normal variability of the pressure was known. A clamp was then applied to the right renal artery. If the rise in pressure which followed showed no tendency to disappear, hypophysectomy was performed by the subtemporal method of Sweet 3 , 4 (4 animals). This method allows one to remove the whole hypophysis intact under visual guidance. Consequently it was not necessary to kill the animals to ascertain whether the operation had been complete. Failing a sufficiently steady, elevated level of arterial pressure, a clamp was applied to the left renal artery (2 animals). In cine case, 5 days after the left clamp was applied, the left kidney was removed and 180 clays later the right clamp tightened. In 3 animals, in which the right kidney had been clamped before hypophysectomy, clamps were applied to the left kidney after hypophysectomy. Clamps were applied to both kidneys after hypophysectomy in 4 animals.