Enzyme activity patterns in white and red muscle of the eel ( Anguilla anguilla) at different developmental stages

Abstract

1. 1. The activities of HK,∗ G6PDH, 6-PGDH, GPDH, PK, LDH, SDH, FUM, MDH, COX and the LDH isoenzyme ratio were measured in different types of muscle from eel at three distinct developmental stages. 2. 2. Red muscle exhibited considerably higher activities of the hexose monophosphate shunt enzymes (G6PDH and 6-PGDH) and the oxidative enzymes (FUM, MDH and COX) compared to white muscle. 3. 3. The activities of the glycolytic enzymes (PK and LDH) were the same in red and white muscle of the yellow eel and in white muscle of the silver eel. The activities of these enzymes in red muscle of the silver eel were only one-third as great as those in the other muscles. 4. 4. In both white and red muscle of the silver eel the enzyme activities of the hexose monophosphate shunt and of the citric acid cycle were about twice the activities in the corresponding muscles of the yellow eel. The COX activity was considerably higher in respective muscles of the silver eel. 5. 5. The transparent body muscle of the glass eel could not be classified as being of white or red type. It was characterized by a low HK activity and high COX activity compared to the activities of the citric acid cycle enzymes.