The role of the pineal gland in reproduction.

The present paper presents a number of results concerning the role of the pineal gland in reproduction. It has been demonstrated that the pineal polypeptides and a substance isolated by the author from children's urine and proved to have pineal extract-like actions, administered to laboratory animals induced the following effects: 1) inhibition of the exogenous HCG stimulating effect on mouse uterus, 2) decrease in excretion of the 17-KS of both testicular and adrenal origin, 3) decrease in the testis oxygen consumption in vitro, and 4) marked decrease of the serum and testicular testosterone. Melatonin, a pineal indole, studied in parallel did not alter the above biochemical indices. Pinealectomy produced in all the cases completely opposite effects. The effects obtained with the pineal polypeptides, the urinary antisteroid substance, and melatonin are discussed.