[The effects of long-term intake of restricted calcium, vitamin D, vitamin E and cadmium-added diets on the skeletal muscles of mice: an enzyme histochemical study].

To clarify the effect of chronic cadmium exposure on muscles, 29-day-old female ICR strain mice were separated into 7 groups and various diets were given to each group. Group I a commercial diet (Intact), Group II a diet low in calcium and low in vitamin D, Group III a diet low in Ca, low in D and low in vitamin E, Group IV a low in Ca, low in D and 20ppm cadmium-added diet, Group V a low in Ca, low in D and 40ppm Cd diet, Group VI a low in Ca, low in D, low in E and 20ppm Cd diet and Group VII a low in Ca, low in D, low in E and 40ppm Cd diet. The levels of vitamin D and vitamin E were designed to be low in each diet but their amounts fulfilled the minimum nutritional requirements. The experimental period was long, ranging from 29 days to 24 months. Using a microscope, two skeletal muscles, the soleus (red muscle) and the gastrocnemius (white muscle) of mice with chronic Cd effects were observed after staining with H. E. and analyzed after enzyme histochemical reaction to ATPase. Using ATPase stain, type I muscle fibers were distinguished from type II muscle fibers. The long-term effects of cadmium. 1) Comparisons among groups II, IV and V. After 18 months it was found in group IV that myopathic muscle damage (increased random variation of fiber size [Size] and widening of interstitial tissue [Widening]) were more prominent that in group II. In group V myopathic muscle damage (Size and Widening) and type II atrophy were more prominent that in group IV. At 24 months it was found in group IV that myopathic muscle damage (Size, internal nuclei [IN] and Widening) and type I and type II atrophy were more prominent than in group II. In group V myopathic muscle damage (Size, IN and Widening) and type I and type II atrophy were more prominent than in group IV. 2) Comparisons among group III, VI and VII.(ABSTRACT TRUNCATED AT 400 WORDS)