人指屈肌和指伸肌的肌纤维型构成及年龄差异

COMPOSITION OF FIBER TYPES IN HUMAN FLEXOR AND EXTENSOR DIGITORUM MUSCLES OF DIFFERENT AGES

用尸检取材(死后24小时内),肌球蛋白ATP酶染色法,检测了不同年龄组(共18例,3～69岁)指浅屈肌、指深屈肌和指伸肌的肌纤维型构成.结果表明:中青年组各肌的Ⅰ型纤维比例分别为指浅屈肌47.2%,指深屈肌44.7%,指伸肌47.7%,各肌之间无明显差异.肌纤维型构成随年龄增加而明显变化,各肌Ⅰ型纤维比例均表现为少儿组较高,中青年组较低,而老年组又明显增高,三组之间具有显著差异.文中还讨论了肌纤维型构成与年龄的关系.

The fiber composition of human flexor and extensor digitorum muscles was studied by autopsy. Samples were taken from 18 cadavers within 24 hrs after accidental death from 3-69 years old. Type I and Type II fibers were distinguished by using myosin ATPase reaction. The results showed that in the young and middle age group (22 ~ 42 years old) the proportion of Type I fiber of the flexor digitorum superficialis was 47.2% of the flexor digitorum profundus 44.7% and of the extensor digitorum 47.7%. There were no remarkable differences among various muscles. However, the proportion of Type I fiber was higher in the children group (3~ 12 years old) than that in the young and middle age group, while in the old age group (50 ~ 69 years old) it increased again. Square deviation analysis revealed that the differences among different age groups were significant, the relation between the composition of fiber types and the function of the muscles is discussed.