Portal blood flow during and after high-intensity physical exercise in rats: response of plasma endothelin-1 and catecholamine

Abstract

The aim of the present study was to measure the portal endothelin-1 (ET-1) and catecholamine response during high-intensity physical exercise. ET-1 and catecholamine response in the hepatic vein (HV) and the portal vein (PV) during treadmill running for 20 min at 25 m/min (15% grade) and the recovery phase for 30 min was measured in male Sprague-Dawley rats. The portal venous flow decreased significantly immediately after starting exercise ( p<0.01), and remained low throughout the recovery period ( p<0.01). Exercise significantly increased epinephrine and norepinephrine levels in the inferior vena cava, but not in PV. After starting exercise, the ET-1 level increased more in PV than in HV, resulting in an immediate increase in the difference in ET-1 levels between PV and HV blood. In the recovery phase, ET-1 levels also increased in PV and HV. Plasma alanine aminotransferase, aspartate aminotransferase, lactate dehydorogenase and guanase activities increased after the high-intensity exercise ( p<0.05) and the hyaluronic acid uptake by the liver was significantly reduced after the exercise ( p<0.05). We concluded that ET-1, rather than catecholamine, has a regulatory action in portal hemodynamics in severe exercise, and it is suggested that the exercise induces slight damage to hepatocytes.