Effect of calorie restriction on mortality kinetics in inbred strains of mice following 7,12-dimethylbenz[a]anthracene treatment

Calorie restriction (CR) has long been known to increase longevity and to delay the onset and to decrease the incidence of many age-related disease processes. The mechanism(s) by which these outcomes are attained is unidentified. This experiment was designed to examine whether differences existed in the extent to which various inbred strains of mice respond to CR. This work explored whether carcinogen-treated animals could be used to facilitate this aim by decreasing the time needed to observe differences in mortality kinetics between CR mice and ad libitum (AL) fed controls. Female mice from each of eight strains (A/J, BALB/c, C3H, C57BL/6, DBA/2J, FVB/J, NMRI, and 129/J) were given a single oral dose (65 mg/kg) of the carcinogen 7,12-dimethylbenz[a]anthracene and subsequently fed AL or calorically restricted. Following carcinogen treatment, the spectrum of lesions observed demonstrated genotypic variability, thereby complicating comparison among the inbred strains examined. However, in terms of the magnitude of alteration in mortality kinetics observed, a statistical analysis revealed that differences exist among the various strains of mice in their response.