Abstract
This investigation was carried out to know whether the secretion of androgen from the newborn rat testis is stimulated by the pituitary or placental gonadotropin. Administration of 100 IU of HCG or PMS for 4 days from day-0 to day-3 of life resulted in a significant increase in the testicular weight and an increase in amounts of interstitial tissue only. Hemicastration on day-0 of life caused a significant increase in the weight of the remaining testis 72hrs. after the operation. Daily injections of 0.025mg of testosterone from day-0 to day-3 of life retarded the normal growth of testis. From these results, it is suggested that the hypothalamo-pituitary testicular axis functions already in the early postnatal period and pituitary ICSH stimulates the testis to produce androgen.
