Growth Curves and Survival Characteristics of the Animals Used in the Biomarkers of Aging Program

TLDR

The Interagency Agreement between NCTR and NIA aimed to identify and validate a panel of aging biomarkers in rodents to rapidly test interventions and to lay groundwork for human biomarkers applicable across genotypes and species. Using caloric restriction as a lifespan‑extending intervention, the study bred and maintained seven mouse and rat genotypes, housing over 60,000 individually housed animals with half on ad libitum and half on CR, and distributed them between NCTR and international NIA investigators. The collaboration provided investigators with healthy, long‑lived rodent models and generated definitive data on lifespan, food consumption, and growth characteristics across genotypes under different feeding regimes.

Abstract

The collaborative Interagency Agreement between the National Center for Toxicological Research (NCTR) and the National Institute on Aging (NIA) was aimed at identifying and validating a panel of biomarkers of aging in rodents in order to rapidly test the efficacy and safety of interventions designed to slow aging. Another aim was to provide a basis for developing biomarkers of aging in humans, using the assumption that biomarkers that were useful across different genotypes and species were sensitive to fundamental processes 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. C57BI/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 individually housed animals of the seven different genotypes and both sexes, approximately half ad libitum (AL) fed, the remainder CR. Approximately half the animals were shipped to offsite NIA investigators internationally, with the majority of the remainder maintained at NCTR until they died. The collaboration supplied a choice of healthy, long-lived rodent models to investigators, while allowing for the development of some of the most definitive information on life span, food consumption, and growth characteristics in these genotypes under diverse feeding paradigms.