Protein Metabolism in Alcohol Misuse and Toxicity

We studied relations between alcohol intake, body mass index, and diet in 89,538 women and 48,493 men in two cohort studies. Total energy increased with alcohol consumption (partial r = 0.11, P less than 0.001), and carbohydrate intake decreased from 153 g/d in abstainers to 131 g/d in women drinking 2.5.0-49.9 g alcohol/d. The decrease in carbohydrate intake was due mainly to decreased sugar consumption with higher alcohol intake (partial r = -0.05, P less than 0.001), reflecting decreased energy consumption from sources excluding alcohol. In men total energy increased with alcohol consumption (partial r = 0.19, P less than 0.001), from 7575.6 (abstainers) to 9821.5 kJ/d (greater than 50 g alcohol/d). Energy intake excluding alcohol varied little with alcohol intake (partial r = 0.003, P = 0.48) but sucrose intake decreased with higher alcohol intake. These data suggest that calories from alcohol were added to energy intake from other sources in men, and that in women, energy from alcohol intake displaced sucrose. The consumption of candy and sugar is inversely related to alcohol intake, raising the possibility that it is related to appetite for alcohol.

A rapid procedure for measuring the specific radioactivity of phenylalanine in tissues was developed. This facilitates the accurate determination of rates of protein synthesis in a wide range of tissues by injection of 150 mumol of L-[4-(3)H]phenylalanine/100 g body wt. The large dose of amino acid results in a rapid rise in specific radioactivity of free phenylalanine in tissues to values close to that in plasma, followed by a slow but linear fall. This enables the rate of protein synthesis to be calculated from measurements of the specific radioactivity of free and protein-bound phenylalanine in tissues during a 10 min period after injection of radioisotope.