Effects of exercise on the lipoprotein‐induced endothelial calcium signaling changes in rat aortas

Abstract

Exercise training improves vascular endothelial functions, while oxidized low-density lipoprotein (oxLDL) impedes them. We proposed that exercise training might influence the endothelial sensitivity to lipoprotein-induced vascular changes. Male Wister rats either ran on a treadmill for 8 weeks or remained sedentary as the control. The endothelial calcium signaling in vitro was examined using dissected aortic segments treated with different lipoproteins, including native LDL (nLDL), various oxLDLs, and HDL. Results showed that none of the various lipoproteins directly evoked endothelial calcium signaling. The acetylcholine-evoked endothelial calcium elevation in control group was increased by nLDL, and progressively suppressed by oxLDLs with increasing degrees of oxidation. When HDL was mixed with various oxLDLs, the suppressive effects by oxLDLs were reduced. Moreover, although exercise training did not affect the basal endothelial calcium level, it ameliorated the oxLDL-induced suppressive effects on acetylcholine-evoked calcium signaling. Taken together, one of the beneficial effects of exercise training on vascular functions is to make blood vessels more resistant to the adverse effects of oxLDL.