ABSTRACT
Researchers in gerontology have been devoting increased efforts into studying functional and subcellular alterations with age in the hope of finding the cause or causes of aging. One problem is that rats, as well as man, usually die with multiple pathological processes. Gerontologists have been trying to differentiate what constitutes a "true" aging process and what is a disease that incidentally happens to be age associated. In rats that die spontaneously, age-associated lesions are multiple and are both neoplastic and nonneoplastic. The combined result of all changes is death. In rats and man, the incidence of cancer increases significantly with age. most investigators in aging research try to separate cancer from the aging process. Therefore, pathologic lesions, either neoplastic or nonneoplastic, cannot easily be separated from the aging process. It is extremely important to keep these age-associated lesions in proper perspective when doing aging research with rats.
