Growth curves and survival characteristics of the animals used in the biomarkers of aging program

The collaborative Interagency Agreement between the National Center for Tox icological Research (NCTR) and the National Institute on Aging (NIA) was ai med at identifying and validating a panel of biomarkers of aging bl rodents ill order to rapidly test the efficacy and safety of interventions designe d to slow aging. Another aim was to provide a basis for developing biomarke rs of aging in humans, using the assumption that biomarkers that were usefu l across different genotypes and species were sensitive to fundamental proc esses that would extrapolate to humans. Caloric restriction (CR), the only intervention that consistently extends both mean and maximal life span in a variety of species, was used to provide a model with extended life span. C 57B1/6NNia, DBA/2JNia, B6D2F1, and B6C3F1 mice and Brown Norway (BN/RijNia) , Fischer (F344/NNia) and Fischer x Brown Norway hybrid (F344 x BN F1) rats were bred and maintained on study. NCTR generated data from over 60,000 in dividually housed animals of the seven different genotypes and both sexes, approximately half ad libitum (AL) fed, the remainder CR. Approximately hal f the animals half shipped to offsite NIA investigators internationally wit h the majority of the remainder maintained at NCTR until they died. The col laboration supplied a choice of healthy, long-lived rodent models to invest igators, while allowing for the development of some of the most definitive information on life spall, food consumption, and growth characteristics in these genotypes under diverse feeding paradigms.