Comparative morphological study of age related mitochondrial changes of the lymphocytes and skeletal muscle cells.

The age dependent electron microscopic changes of the mitochondria in a mitotic cell (lymphocyte) were compared with those of a postmitotic cell (skeletal muscle cell) in humans and in CBA/Ca mice. Two types of age related changes could be observed in the mitochondria of lymphocytes and skeletal muscle cells: (i) degenerative changes; (ii) giant mitochondria. The frequency of the mitochondrial changes increased with age and were more frequent in the skeletal muscle cells than in the lymphocytes.