Castration, as well as the menopause, represents endocrine suppression that prevails the hipoestrogenism and their larger consequence on the skeletal muscle is to provoke sarcopenia. OBJETIVE: To study the morphometric alteration of striated muscle of castrated female rats. METHODS: Twenty six female rats Wistar , distributed in two sub-groups, A and B, submitted initially to weigh-in place, vaginal cytology, ovariectomy, and biopsy of the muscle rectus femoris on the back paws, A group on right paw, and B on the left. Elapsed 20 days it was collected vaginal cytology to prove the anestrus status. After 70 days the animals went through weigh-in place, and new muscle biopsy, A group in left paw and B in right paw. The morphometric study was accomplished with the aids of a graduated lens, with reticules of 100 mm², it was counted the myofibrils with six readings in the vertical and five in the horizontal in each sheet, being obtained a multiple number that applied on a specific formula to calculate the coefficient of muscular density. RESULTS: In A the muscular density varied from 60.0 to 52.33, (p<0,05%), with variation of 14,12%, and in B from 73.5 to 54.0, (p<0,05%), with variation of 26,53%. CONCLUSION: The castration provoked sarcopenia in the striated muscle and reduction of myofibrils number.
Castration; Rats; Skeletal Muscle; Histomorphometry; Sarcopenia
