The purpose of this study is to determine whether Branched chain Amino Acids enhances the uptake of ammonia in muscle tissue.

Branched-chain amino acids (BCAA; leucine, valine, isoleucine) are used to prevent hepatic encephalopathy in cirrhotic patients. The main effect of BCAAs is believed to take place in muscles where BCAAs provide carbon-skeletons for the TCA-cycle. This enhances the conversion of alfa-ketoglutarate to ammonia via glutamine.

We 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; L/min) 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 BCAA/kg body weight) and after 1 and 3 hours. The metabolism of ammonia will also be estimated by means of 13N-NH3 PET scans.

Hypothesis: BCAA increases the uptake of ammonia in muscle tissue and lowers arterial ammonia.

Inclusion Criteria:

• 18 patients with liver cirrhosis
• 6 healthy subjects age and sex matched

Exclusion Criteria:

• Non-treated diabetes
• Pregnancy/breast-feeding