HEPATIC ORNITHINE DECARBOXYLASE ACTIVITY DURING SHORT-TERM STARVATION AND REFEEDING IN BROOK TROUT, SALVELINUS-FONTINALIS

Ornithine decarboxylase (ODC) has been identified as a key enzyme in the regulation of growth in higher vertebrates. The aim of this research was to determine ODC activity during short-term starvation and refeeding in fish. Hepatic ODC activity declined exponentially during 6 days of starvation in underyearling brook trout, and was closely correlated to the amount of food in the digestive system. After a 12-day starvation period, hepatic ODC activity was elevated within 4 h of refeeding, and continued to rise exponentially over a 24-h period. The sensitivity of hepatic ODC activity to starvation and refeeding suggests that the activity of this enzyme may serve as a useful tool in assessing the nutritional status of fish.