Glycolytic Enzyme Activities in Leukocytes of Thoroughbreds Undergoing Training Exercise.

Glycolytic enzyme activities and expression of glucokinase (GK) were investigated in leukocytes (WBC) from Thoroughbreds, racehorses undergoing continuous training exercise and riding horses. Glycolytic enzyme activities in WBC from racehorses were higher than those from riding horses. Especially activities of GK, rate-limiting enzyme of glycolysis, were significantly higher in WBC from racehorses than in those from riding horses. Analysis of reverse transcription-polymerase chain reaction (RT-PCR) with specific primer for GK showed that expression of mRNA of GK was remarkably increased in WBC from racehorses. This suggested that activities and gene expression of some kinds of glycolytic enzymes including GK in WBC are possibly a good indicator for assessing glucose metabolism in Thoroughbreds undergoing training exercise.