Pineal, neural and photic control of reproductive organ size in early androgen-treated male rats

If male albino rats are blinded at 21 days of age, their body weights as well as the weights of the testes, seminal vesicles and coagulating glands are significantly smaller than normal at 78 days of age. Similarly, the gonads and accessory sex organs (seminal vesicles and coagulating glands) of male rats treated with 1.25 mg testosterone propionate shortly after birth fail to develop normally. The inhibitory response due to blinding is prevented by removal of the pineal gland, whereas pincalcctomy has no effect on gonadal size in androgen-treated rats. When rats are treated with testosterone propionate and blinded, the testes and accessory organs of 78-day-old animals are grossly and micro- scopically infantile unless the animals arc cither pinealectomizcd or superior cervical ganglionectomizcd, in which case the gonads grow to the level of those in androgen- treated rats.