PINEAL ACID-PHOSPHATASE-ACTIVITY IN SYRIAN-HAMSTERS - SEX-DIFFERENCESAND EFFECTS OF CASTRATION AND ANDROGEN REPLACEMENT THERAPY

Pineal acid phosphatase (ACP) activity was examined in seven experimen ts involving young intact or castrated male and female Syrian hamsters . Nine-week old female hamsters had a 3-fold (p < 0.001) higher ACP ac tivity in their pineal glands than did males. After three weeks of cas tration, a significant increase (p < 0.001) in ACP activity occurred i n castrated male pineal glands. In males, pellets with 5 alpha-dihydro testosterone (p < 0.01) but not testosterone or progesterone suppresse d pineal ACP activity. In females, no changes in pineal ACP activity w ere noted due to the estrous cycle. Pineal ACP activity was not affect ed by testosterone, dihydrotestosterone or androstenedione pellets in intact females or by testosterone pellets in ovariectomized animals.