|Budget Amount *help
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1990: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥1,300,000 (Direct Cost: ¥1,300,000)
There have been many studies of atrophy in skeletal muscles. And their aims are widely covered in morphological, and tension. Recently, atrophy is created by the tail suspension method and changes of structure of protein are studied and reported the the creation of procedure to examine. We created the atrophy through gypsum immobilization by plaster and examined the changes in muscles and capillaries and their recovery procedure.
In the year of 1988, the period of immobilization, atrophy of muscles, and changes of muscles were examined in growing male rats. The ratio of atrophy increase depending upon the length of period in one, two, and four weeks of the immobilization, and each crossing area of muscle fibers in soleus muscles are 88%, 77%, and 65%. The same atrophy in soleus muscles can be seen in extensor digitorum longus EDL as well ; however, there are some muscles in four weeks reversely hypertrophied than the other side of muscles. There is no change of C/F ratio in capillaries.
In the year of 1989, female rats are examined. Female rats show atrophy clearer than male rats, and between young rats and old rats, younger rats show more atrophy than old ones. Observing this change by an electronic microscopy, it can be seen that the irregularity of Z bands in skeletal muscles, the roughness of muscle fibrils, increase of glycogen, and concentration of mitochondria. The arrangements of muscle fibrils are disordered because of the roughness and disappearance of muscle fibrils in further progress of atrophy, and actin and myosin are replaced into micro-fibrous matters. It is also observed in a horizontal crossing image that six actin structure are disordered toward myosin. This abnormal of arrangement cause the decrease of tension.
In the year of 1991, recovery is examined. 4, 6, and 8 weeks of exercises (loading of swimming) applied to the atrophied skeletal muscles which are created by four weeks immobilization and observed their recoveries. The size of muscle fibers is totally recovered in 6 or 8 weeks of exercises, and muscle fibrils indicate normal arrangement in micro structure. Less