Age-related morphological changes in lymphocytes as a model of aging.

The same age-related morphological changes have been observed in the lymph node and spleen lymphocytes of old untreated Wistar rats and CBA/Ca mice. The same age-related changes were also observed in the peripheral lymphocytes of healthy humans. The most important changes were seen in the mitochondria of the lymphoid cells. They were sometimes swollen; the mitochondrial cristae disappeared and were replaced by myelin-like forms or filamentous structures. The mitochondrial changes developed only in non-labelled lymphoid cells, presumably the T cells. It is suggested that lymphocytes be used as a morphological model for the study of aging and its modification.