Lipid metabolism in the northern pike (Esox LuciusL.)—3. In vivo incorporation of 1-14C-acetate in the lipids

Abstract

1. 1. The specific radioactivity of the total lipids isolated from different organs of the northern pike (Esox lucius L.) after injection of Na-1-1 4C-acetate showed the highest values in the liver and the gills.

2. 2. In the liver, radioactivity was found mainly in the fatty acids, while in the gills the greater part was present in the unsaponifiable lipids.

3. 3. The percentage incorporation of radioactivity in lipid classes did not change significantly from 2 to 24 hr after injection, but decreased in phospholipids and increased in triglycerides during shorter incubation times.

4. 4. The number of fatty acids labeled as well as the amount of radioactivity incorporated increased rapidly after 1-14C-acetate injection. Virtually all fatty acids were labeled after 2 hr injection.