Influence of beta-adrenoceptor blockade on leg blood flow and lactate release in man

Nine healthy male volunteers were studied at rest and during exercise before and after acute local beta-blockade in one leg. Oxygen uptake, arterial pressure, heart rate, leg blood flow and arterial-femoral venous differences for oxygen and lactate were determined. In addition, five subjects were studied at rest during adrenaline infusion to test the blockade; in this situation the increase in leg blood flow and decrease in resistance seen in the control leg were prevented in the blocked leg. During exercise, the beta-blockade did not influence leg blood flow. At rest, lactate release was abolished from the blocked leg, and during exercise the release was reduced by 50%. These findings demonstrate that acute betareceptor blockade does not interfere with the exercise-induced vasadilation but has metabolic consequences reflected by a reduction in the release of lactate from the leg.