Sustained differential effects of a transient antioxidant diet and voluntary exercise training on vascular functions in aging mice

Abstract

A healthy diet and regular exercise delay cardiovascular diseases in aging, but little is known about the mechanisms. We tested the effects of an early transient antioxidant diet and voluntary exercise on the vascular function of aging mice. One month old C57/Bl6 mice were split into 3 groups: one was supplemented with the antioxidant catechin (30mg/kg/d; CAT), a second was given access to an exercise wheel (EX) and a third remained sedentary (S), all until 9 months (9m). Mice were then aged for another 3 months in sedentary conditions with no treatment (12m). Femoral artery reactivity and compliance were assessed in a pressure myograph (80 mm Hg). At 9m, arterial compliance, represented by the Young's elastic modulus (β), did not differ between S (0.08±0.01) and CAT (0.08±0.01) mice, while it was greater in the EX group (0.05±0.01, p<0.05); 12m mice retained their elastic properties except for the EX group (0.07±0.01, p<0.05). The wall media‐tolumen ratio was similar in all groups. Endothelium‐dependent dilations to acetylcholine were similar in all groups at 9 and 12m. This dilatory response was, however, reduced by 60% (p<0.05) after inhibition of NO production in S mice, but not in the other groups at both ages. In conclusion, both CAT and EX improved vascular endothelial function by preserving NO‐independent vasodilator mechanisms, while only EX improved arterial compliance. Supported by CIHR MOP14496.