Exercise-induced Tissue-specific Change in Gene Expression of Endothelin-1

Abstract

Exercise causes an integrated physiological response (e.g., an increase in cardiac output and a significant redistribution of tissue blood flow), which greatly increases blood flow in active muscles but decreases it in the splanchnic circulation. Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelial cells. We hypothesized that exercise causes a tissue-specific change in ET-1 production in various organs. We studied whether a bout of exercise alters the expression of preproET-1 mRNA in various tissues of rats. The rats were randomly divided into exercise rats and control rats. Exercise rats performed treadmill running for 30 minutes at a speed of 30 m/minute. Control rats remained at rest during the same period (30 minutes). Immediately after the exercise and rest, the abdominal artery, liver, muscles (tibialis anterior muscle, plantar muscle and soleus) and adipose tissue were quickly removed and the expression of preproET-1 mRNA in these tissues was determined by real-time quantitative polymerase chain reaction analysis. The expression of preproET-1 mRNA in these tissues was changed in a different manner by acute exercise (i.e., increased, decreased, or unchanged). The expression of preproET-1 mRNA in the aorta was significantly decreased by exercise, whereas that in the plantar muscle was significantly increased by exercise. There were no significant differences in the expression of preproET-1 mRNA in the liver, tibialis anterior muscle, soleus and adipose tissue between the exercise rats and the control rats. These results show that the expression of preproET-1 mRNA was changed tissue-specifically by acute exercise. We demonstrate that acute exercise causes tissue-specific changes in the production of ET-1 and that these alterations may participate in the integrated physiological response during exercise.