Effects of hypophysectomy on alloxan-diabetic, arteriosclerotic, breeder vs. non-arteriosclerotic, virgin rats.

A single s.c. injection (10 mg/100 g bw of alloxan) was given to nonarteriosclerotic, virgin, Sprague--Dawley rats and to breeder rats with preexisting arteriosclerosis, hyperlipidemia and hyperglycemia. All of the animals promptly developed severe diabetes with ketosis, hyperglycemia, and hyperlipidemia. Insulin therapy was deliberately withheld. Mortality was high. Seven days later one group was subjected to hypophysectomy and 30 days later, all of the animals were autopsied. The diabetes + hypophysectomy animals maintained their body weight better, did not have hypertrophied adrenal glands, showed the least elevation of serum enzymes, e.g., CPK, SGOT, SGPT and LDH, less hyperlipidemia and hyperglycemia and reduced corticosterone production than the animals with untreated severe diabetes. Despite the relative amelioration of metabolic derangements prognostic of cardiovascular degenerative changes, the diabetes + hypophysectomy animals manifested extensive renovascular damage and the breeder rats with pre-existing arteriosclerosis showed definite exacerbation of their arterial disease in response to the severe alloxan diabetes regardless of hypophysectomy. It is suggested that although hypophysectomy may alleviate certain metabolic derangements attributed to growth hormone, ACTH and adrenal steroids, the angiopathic damage proceeds inexorably.