Schmucker D L, Sachs H G
Mech Ageing Dev. 1985 Jun;31(1):89-101. doi: 10.1016/0047-6374(85)90028-4.
A quantitative electron microscopic examination of the ventricular myocardium of the male Fischer 344 rat was undertaken to determine the extent of age-dependent changes in ultrastructure. Rats of 6, 16 and 30 months of age were examined using a non-biased stereological test system. Volume fractions of mitochondria, myofibrillar mass and lipid remained unchanged during aging. Dense body volume fraction increased four-fold over the period studied, while the sarcoplasmic reticulum volume increased only from 6 months to 16 months and did not change thereafter. Biochemical analysis of the specific activities of the two lysosomal enzymes, acid phosphatase and beta-glucuronidase demonstrated a differential response to aging, with acid phosphatase remaining constant and beta-glucuronidase increasing slightly. Neither enzyme activity correlated with the pronounced change in dense body volume fraction. This study provides clear evidence that the previously observed changes in cardiac performance associated with aging are not readily explicable on the basis of a degradation of cardiac ultrastructure.
对雄性Fischer 344大鼠的心室心肌进行了定量电子显微镜检查，以确定超微结构中年龄依赖性变化的程度。使用无偏倚的体视学测试系统对6、16和30月龄的大鼠进行了检查。在衰老过程中，线粒体、肌原纤维质量和脂质的体积分数保持不变。在所研究的时间段内，致密体体积分数增加了四倍，而肌浆网体积仅在6个月至16个月之间增加，此后没有变化。对两种溶酶体酶酸性磷酸酶和β-葡萄糖醛酸酶的比活性进行生化分析，结果显示它们对衰老的反应不同，酸性磷酸酶保持不变，而β-葡萄糖醛酸酶略有增加。两种酶的活性均与致密体体积分数的显著变化无关。这项研究提供了明确的证据，表明先前观察到的与衰老相关的心脏性能变化，不能轻易地基于心脏超微结构的退化来解释。
