| Abstract: | After incubation of rat, pig and cattle skeletal muscle homogenates with U-14C]leucine, 80.4%, 37.0% and 57.0% of radioactivity was found in the proteins, 9.4%, 58.7% and 40.9% in the lipids, and 10.2%, 4.3% and 2.1% in 14CO2. This suggests that along-side with utilization in protein synthesis, leucine plays an essential role in lipid synthesis in muscle tissues of agricultural animals. The contribution of U-14C]leucine to lipogenesis with substrates is greater than that of U-14C]acetate and U-14C]glucose in cattle skeletal muscles in vitro and greater than that of U-14C]acetate in pig muscle. The CO2 production during oxidation of the U-14C]leucine carbohydrate chain is higher than that during U-14C]glucose and U-14C]palmitate oxidation in skeletal muscles of rat and pig. In skeletal muscles of all animal species under study U-14C]acetate is oxidized far more intensively than the other substrates tested. |
