Ketone Bodies in the Blood of Salmonoid Fishes

Abstract

The concentration of acetoacetate expressed as acetone in the blood of rainbow trout (Salmo gairdnerii) was generally in the range of 0.3-1.0 mg/100 ml and long periods of starvation did not appear to affect this level to any appreciable extent. In sockeye salmon (Oncorhynchus nerka) in the pre-spawning stage of migration the concentration of acetoacetate was within the range found for rainbow trout. Higher concentrations of acetoacetate, amounting to approximately 1.5 mg/100 ml of blood, were present in sockeye salmon at the spawning grounds. Rainbow trout, which had been exercised, yielded greater value for [beta]-hydroxybutyrate, and it was shown that under these conditions lactic acid interfered with the determination of [beta]-hydroxybutyrate. Starvation of rainbow trout did not affect the concentration of [beta]-hydroxy-butyrate to any appreciable extent. In spawning salmon [beta]-hydroxybuty-rate showed some increase, as compared with fish in the pre-spawning stage of migration.