Effects of Chronic Swimming Training on ET-1 in Plasma and Thoracic Aorta in aging Old Rats

The purpose of this paper is to investigate the effect of Chronic different duration and times swimming training on endothelin-1 in plasma and thoracic aorta in aging rats. Methods: 2 months old SD male rats were selected as young sedentary control group, and 9-10 months SD male rats as aging groups. 9-10 months rats were divided into sedentary control group and 14-week swimming training groups. Swimming training rats were divided into one-hour swimming training per day (6 days/week), two-hour swimming training per day (6 days/week), and one-hour swimming training per day (3 days/week). ET-1 protein in thoracic aorta and plasma were determined by radiommunoassay. Results: (1) with aging, the concentration of the plasma ET-1 has no changes, while the that of ET-1 in thoracic aorta increase significantly. (2) Compared with aging control group,the concentration of the plasma ET-1 increased lightly but no significant difference in swimming training groups, and there is no significant difference among swimming training groups; but the concentration of ET-1 in thoracic aorta decrease significantly in swimming training rats. Conclusions: ① with aging, the concentration of ET-1 in thoracic aorta increased may result from the damage in endothelium induced by aging; findings indicate that the plasma ET-1 can not exactly reflect ET-1 level in thoracic aorta . ②Swimming can lower the concentration of thoracic aorta ET-1 when its level increase induced by aging, thus abating pathopoiesis of endothelin-1. ③ After swimming training, the concentration of the plasma ET-1 increased moderately, which maybe contribute to strengthen myocardial constriction.