Further data on the androgenic dependency of the skeletal musculature: the effect of prepubertal castration on the structural development of the skeletal muscles.

The effect of prepubertal castration was investigated in the soleus, semimembranosus and levator ani muscles of rat, using light and electronmicroscopic morphometric methods. After castration the semimembranosus and the levator ani muscles showed significant morphometrical alterations. The weight of the muscles diminished, the diameter of the white fibers decreased. The ultrastructure of these muscles showed a well expressed myofibrillar atrophy. The changes in the semimembranosus muscle were less severe. The slow oxidative soleus muscle did not show any similar alterations. The changes in the levator ani and semimembranosus muscles could be prevented or moderated by testosterone substitution.