<qa>  What is the effect of oral administered BCAA on the metabolism of ammonia and amino acidsWe intend to study the effect of oral administered BCAA on the metabolism of ammonia and amino acids across the leg-muscles by means of catheters inserted into the femoral artery A and vein V. Muscle blood flow F; Lmin will be determined by constant infusion of indocyanine green and indicator dilution principle. Arterial blood flow and A and V concentrations of ammonia and amino acids will be measured before an oral load of BCAA 0.45 g BCAAkg body weight and after 1 and 3 hours. The metabolism of ammonia will also be estimated by means of 13N-NH3 PET scans. 