Effect of cold exposure, exercise and high altitude on plasma endothelin-1and endothelial cell markers in man

The aims were to examine the effect of cold exposure, exercise and high alt itude on plasma concentrations of big endothelin-1, endothelin-1, von Wille brand factor and serum e-selectin in twenty five healthy male volunteers. C linical evaluation and venesection were performed before and after 24 hours of low altitude mountaineering, exposure to temperatures of -18 degrees C and +4 degrees C and whilst ascending from sea level to an altitude of 5000 m in the Karakoram. Plasma big endothelin-1, plasma endothelin-1 and serum soluble e-selectin concentrations were significantly elevated after two hou rs at -18 degrees C (p < 0.05, p < 0.05 and p < 0.01 respectively). At +4 d egrees C, plasma big endothelin-1 and endothelin-1 concentrations rose sign ificantly after 5 hours (p < 0.005 for both) but not after 2.5. hours. Low altitude mountaineering did not alter circulating marker concentrations. At high altitude, big endothelin-1 and endothelin-1 (p < 0.01 for both) rose significantly at 2500m and initially at 5000m but returned to sea level val ues after prolonged exposure to 5000m. Serum e-selectin rose at all altitud es greater than sea level (p < 0.05). In conclusion, exposure to high altit ude, moderate cold or freezing temperatures, but not exercise, selectively activates endothelial cells increasing endothelin-1 production. Cold exposu re may contribute to the observed increase in plasma endothelin-1 in mounta ineers at high altitude.