其他摘要：The purpose of this study was to inquire histologically the effect of sexual hormones on the development of skeletal muscle fibers making a distinction among red muscle fibers, medium muscle fibers and white muscle fibers. The experimental animals, Wistar-strain rats of the same venter, were divided into the following four groups on 21 days after birth: (1) Control group of males (2) Castration group of males (3) Injection group of Ovahormon (Benzoate Suspension 1000 Unit) into the male castration (4) Control group of female. The 0.2 ml of Ovahormon was injected into the third group on every other day. M. tibialis ant. of each group was removed on 70 days after birth and the histological method, using Sudan black B, was adopted in this experiment. The results obtained were as follows: (1) Rate of increasing of rats' body weight in the castration group of males was smaller than that in the control group of males and the tendency of that in the injection group of Ovahormon into the male castration was smallest among the four groups. (2) Rate of increase in muscle weight of rats' lower limbs (M. tibialis ant., M. gastrocnemius, M. soleus, M. plantalis and M. ext. digi. longus) showed the same tendency as that of body weight. (3) The decreasing rate of the entire cross sectional area of M. tibialis ant. in the castration group of male was 5.1% in red muscle fibers, 8.8% in medium muscle fibers and 3.6% in white muscle fibers. In the injection group of Ovahormon into the male castration each respective value of those was 20.3%, 25.8% and 29.0%. (4) The decreasing rate of the average cross sectional area per fiber in the castration group of males and the injection group of Ovahormon into the male castration showed the same tendency as that of the entire cross sectional area in red, medium and white muscle fibers.
