Abstract
The growth of the ventral and the dorsolateral prostate, the coagulating glands, seminal vesicles and levator ani muscle was studied in castrated male rats after fifteen days of daily injections with ACTH or insulin alone, or in combination. ACTH was given in a dose of 8 IU daily. Insulin was administered in increasing daily doses, i. e. regular insulin up to 8 IU and protamine zinc insulin up to 10 IU. After ACTH treatment there were variable histological signs of stimulation of the dorsolateral prostate, while the other accessory reproductive organs showed no response. Regular insulin produced no quantitative or morphological changes in the accessory reproductive organs, and no morphological signs of increased secretion of the adrenal steroids. Administration of ACTH and regular insulin in combination stimulated the growth of all the accessory reproductive organs. Protamine zinc insulin produced prolonged hypoglycaemia and morphological signs of increase secretion of adrenal steroids, thus the adrenals became enlarged and the thymus atrophic. Protamine zinc insulin stimulated growth of all the accessory reproductive organs, a stimulation which was further accentuated after combination with ACTH. Possible mechanisms for the action of insulin on the male accessory reproductive organs are discussed. The varying response of the different parts of the prostate and the seminal vesicles emphasizes the importance of the simultaneous examination of these organs.