MODERATE AND LARGE DOSES OF ETHANOL DIFFERENTIALLY AFFECT HEPATIC PROTEIN-METABOLISM IN HUMANS

The intake of similar to 70 g alcohol impairs liver protein metabolism in healthy humans. To establish the threshold at which alcohol impair s hepatic protein metabolism in humans we compared the effects of 500 mL of water (control study), 300 (28.4 g ethanol) or 750 ml (71 g etha nol) of table wine on hepatic protein metabolism in three groups oi he althy nonalcoholic volunteers. Hepatic protein metabolism was estimate d (L-[1-C-14]leucine infusion) by measuring the fractional secretory r ates of albumin and fibrinogen during the overnight postabsorptive sta te (basal) and the subsequent administration of water or two different amounts of wine (300 or 750 mL) given with a liquid glucose-lipid-ami no acid meal. During the meal, water did not affect fibrinogen fractio nal secretory rate and increased albumin fractional secretory rate by similar to 50% (P < 0.01). The 300 mL of wine increased albumin secret ory rate by only similar to 20% (P < 0.01 vs. basal, P < 0.04 vs. wate r) and did not affect fibrinogen secretory rate. The 750 mL of wine pr ofoundly impaired hepatic protein metabolism, decreasing the fractiona l secretory rates of albumin (P < 0.01 vs. water ana 300 mL wine) and fibrinogen (P < 0.04 vs. water and 300 mL of wine) below the postabsor ptive values. These results demonstrate that a moderate dose of alcoho l (28 g, similar to 2 drinks) slightly affects postprandial hepatic pr otein metabolism by blunting the meal-induced increase in albumin synt hesis. whereas it does not interfere with fibrinogen synthesis as do h igher doses.