ABSTRACT
Advanced glycation end-products (AGEs) initiate cellular inflammation and contribute to cardiovascular disease in the elderly. AGE can be inhibited by Alagebrium (ALT), an AGE cross-link breaker. Moreover, the beneficial effects of exercise on aging are well recognized. Thus, we investigated the effects of ALT and exercise (Ex) on cardiovascular function in a rat aging model. Compared to young (Y) rats, in sedentary old (O) rats, end-systolic elastance (Ees) decreased (0.9±0.2 vs 1.7±0.4mmHg/µL, P<0.05), dP/dt(max) was attenuated (6054±685 vs 9540±939mmHg/s, P<0.05), ventricular compliance (end-diastolic pressure-volume relationship (EDPVR)) was impaired (1.4±0.2 vs 0.5±0.4mmHg/µL, P<0.05) and diastolic relaxation time (tau) was prolonged (21±3 vs 14±2ms, P<0.05). In old rats, combined ALT+Ex (4weeks) increased dP/dt(max) and Ees (8945±665 vs 6054±685mmHg/s, and 1.5±0.2 vs 0.9±0.2 respectively, O with ALT+Ex vs O, P<0.05 for both). Diastolic function (exponential power of EDPVR and tau) was also substantially improved by treatment with Alt+Ex in old rats (0.4±0.1 vs 0.9±0.2 and 16±2 vs 21±3ms, respectively, O with ALT+EX vs O, P<0.05 for both). Pulse wave velocity (PWV) was increased in old rats (7.0±0.7 vs 3.8±0.3ms, O vs Y, P<0.01). Both ALT and Ex alone decreased PWV in old rats but the combination decreased PWV to levels observed in young (4.6±0.5 vs 3.8±0.3ms, O with ALT+Ex vs Y, NS). These results suggest that prevention of the formation of new AGEs (with exercise) and breakdown of already formed AGEs (with ALT) may represent a therapeutic strategy for age-related ventricular and vascular stiffness.
