THE LIVER AND MUSCLE OF EARLY UPSTREAM MIGRANT LAMPREYS (GEOTRIA-AUSTRALIS) CONTAIN HIGH-LEVELS OF ACETYL-COA CARBOXYLASE AND A CARNITINE PALMITOYL TRANSFERASE-I THAT IS SENSITIVE TO MALONYL-COA

The exceptionally high lipid levels in the muscle and liver of Geotria australis, at the completion of the marine trophic phase, are both ac companied by a very high activity of acetyl-CoA carboxylase (ACC). ACC activity declines markedly during the subsequent protracted, nontroph ic spawning run, The above and other data suggest that, in lampreys, t he muscle tissue, as well as the liver, is lipogenic. Carnitine palmit oyl transferase I of lamprey muscle is extremely sensitive to malonyl- CoA, a feature which would enable fatty acid oxidation to be inhibited during any period of lipogenesis in this tissue.