Energy metabolism in unrestrained fish with in vivo 31P-NMR

Abstract

1. 1. We evaluated changes in high energy phosphate metabolism in unrestrained freshwater loaches by in vivo 31P-NMR. 2. 2. When dissolved oxygen was deficient, both an increase in Pi and a decrease in PCr were observed as the loach struggled. 3. 3. After pretreating the fish with an anesthetic agent, we observed the dependence of high energy phosphate metabolism on changes in dissolved oxygen. 4. 4. Under anesthetic [Pi]/[Pi] + [PCr] ratio, an index of metabolic state, was lower than without anesthesia. 5. 5. Decrease in high energy phosphate metabolism in fish during oxygen deficiency was not caused by poor oxygen supply but resulted from struggle movement due to lack of oxygen.