The effect of octanoate and palmitate on the metabolism of valine in perfused hindquarter of rat

The effect of octanoate and palmitate on the oxidation of 14C‐labelled valine has been studied in perfused hindquarter of rat. 1 The oxidation rate of valine increases 30 times when the concentration of valine is increased from 0.1 mM to 5 mM. 2 Octanoate at a 5 mM concentration effected a 10‐fold increase in the flux through the α‐keto‐isovalerate dehydrogenase step and a 5‐fold increase at 0.5 mM concentration. 3 Palmitate (1 mM) effects only a moderate increase in the valine oxidation. 4 With no octanoate there was a great accumulation of α‐ketoisovalerate in both the muscle and the perfusion medium. 5 With octanoate little α‐ketoisovalerate accumulated whereas 3‐hydroxyisobutyrate was found in high concentration both in the muscle and in the medium. 6 Octanoate stimulated the production of citric‐acid‐cycle intermediates and lactate. 7 The results are discussed in relation to valine metabolism in the body.