Influence of beta blockade on branched chain amino acid concentrations in cirrhosis.

Cirrhosis of the liver is typically accompanied by low plasma levels of the three branched chain amino acids (BCAA). These patients also demonstrate increased concentrations of several hormones such as insulin, glucagon and catecholamines. Catecholamines have been shown to influence the plasma levels of amino acids in healthy subjects and diabetics. In the present study, amino acid concentrations were investigated before and up to 3 hours after beta blockade (Inderal, 40-80 mg, n = 10) or fasting (n = 8) in cirrhotic patients. In the basal state the patients had low levels of all three BCAA, as compared with healthy subjects. Norepinephrine was more than 3 times as high in the patients (3.65 +/- 0.6 vs. 0.84 +/- 0.08 nmol/l, p < 0.01) while epinephrine was only slightly raised (0.43 +/- 0.1 vs. 0.25 +/- 0.06 nmol/l, NS). Significant correlations were observed between the concentrations of norepinephrine and individual as well as the sum of the three BCAA (r = 0.43-0.62, p < 0.05-0.001), while no correlation was observed between the BCAAs and epinephrine or insulin. Three hours after beta blockade the concentrations of leucine (basal: 74 +/- 6, 180 min: 89 +/- 6 mumol/l, p < 0.05) and valine (basal: 110 +/- 10, 180 min: 132 +/- 11 mumol/l, p < 0.01) had increased significantly. A similar tendency was observed for isoleucine. No changes were observed after prolonged fasting. The results suggest that catecholamines, primarily norepinephrine, might contribute to the low levels of BCAA in cirrhotics.