Regular training enhances the nitric oxide and prostacycline independent endothelium-dependent vasodilation in the cutaneous microcirculation

摘要

Regular physical training is known to enhance endothelium-dependent vasodilation. To which extent the vasodilators, independent of nitric oxide (NO) and prostacycline (PGI2) contribute to this phenomenon remains to be elucidated. We assessed baseline laser Doppler flux (LDF) and acetylcholine (ACh)-induced LDF increase in: 1.endurance-trained cyclists and 2. sedentary controls in the presence and absence of combined endothelial NO synthase (eNOS) and cyclooxygenase (COX) inhibition, respectively. Combined eNOS and COX inhibition had no effect on the baseline LDF in either group. The ACh-stimulated increase in LDF was attenuated after eNOS and COX inhibition. Yet, the remaining vasodilation was significantly greater in the trained. The results may imply an important contribution of endothelial vasodilators, other than NO and PGEs to the training induced adaptation of endothelium in the skin microcirculation.