Age-related association of tail tendon break time with tissue pentosidine in DBA/2 vs C57BL/6 mice: the effect of dietary restriction.

In recent years, there has been a growing interest in the development of a panel of biomarkers useful in the evaluation of interventions on aging processes. An ideal marker should change with age, be related to species longevity, and respond to the effects of dietary restriction, which is the only intervention currently known to increase species longevity. In the present study; we compared parameters of collagen aging (i.e., tail tendon break time [TBT] and the glycoxidation product pentosidine) in tendon, ear, and skin of two species of rodents with different life spans: the shorter-lived DBA/2 versus the longer-lived C57BL/6 mouse strain. Both TBT and tissue pentosidine significantly increased with age in both strains of mice. The rate of increase for TBT And pentosidine occurred faster for the DBA/2 compared with the C57BL/6 strain. Dietary restriction significantly inhibited the age-related increase of TBT and pentosidine formation rte in DBA/2 mice. In C57BL/6 mice, the age-related increase of TBT was significantly inhibited by dietary restriction. However, except for tendon at 24 months, pentosidine level was not affected by dietary restriction. These studies show that the rate of collagen aging, as reflected by TBT and glycoxidation, increases proportionally with age, and that these rate increases are related to longevity in two strains of mice. Pentosidine can be monitored with age just as well in a piece of easily accessible ear tissue as in skin or tendon. Thus, pentosidine is expected to be a useful and easily measurable noninvasive marker in future intervention studies on aging.