AGE-RELATED PATHOLOGY AND BIOSENESCENT MARKERS IN CAPTIVE RHESUS MACAQUES

During the past 15 years, our aging colony of rhesus monkeys, consisti ng of animals from 20 to 37 years of age, had an annual average popula tion of 88.2 live monkeys and, of this population, an annual average o f 13.9 monkeys died spontaneously or were terminated due to severe ill ness. From 1980 to 1994, a total of 175 autopsies of rhesus macaques, from 20 to 37 years of age, were performed. By cumulative autopsy data , the incidence of age-related pathology in various organs was surveye d. Major geriatric diseases such as coronary sclerosis, emphysema, deg enerative joint disorders, cancer, and cerebral amyloid plaque began t o develop in 10 to 40% of macaques after 20 years and the incidence si gnificantly increased after 26 years of age. Approximately 12% of aged macaques from 20 to 30 years of age died annually due to such geriatr ic diseases with severe complications. The average survival rate indic ated that half the population at 20 years of age died by 25 years and 73% died by 30 years of age. Less than 10% of macaques survived over 3 0 years. Using these aged macaques as well as other juvenile to adult monkeys in our Center, clinical opththalmological and reproductive end ocrinological studies, and magnetic resonance imaging (MRI) of the bra in were conducted to define bioaging markers of captive rhesus monkeys . Cataracts began to develop in 20% of rhesus monkeys at 20 to 22 year s of age and the rate significantly increased after 26 years of age. M enopause occurred at 26 to 27 years of age. Multiple cerebral infarcti ons and iron deposits in the globus pallidus and substantia nigra were detected by MRI in the aged brains. These geriatric disorders in capt ive aged macaques appear to be natural aging outcomes, since the simpl e lifestyle of these captive animals offers minimal exposure to enviro nmental factors. Our data will offer useful paradigms for preventive o r experimental studies on age-related diseases.