A COMPARISON OF THE ACTIVITIES OF CERTAIN ENZYMES RELATED TO ENERGY-METABOLISM IN LEUKOCYTES IN DOGS AND CATS

The activities of Na+,K+-ATPase in plasma membrane, of cytosolic enzym es and of glutamate dehydrogenase (GlGD) in mitochondria were measured in leukocytes (WBC) from dogs and cats to clarify the differences in energy metabolism in these cells. Feline WBC had significantly higher activities of hexokinase (I-IK), pyruvate kinase (PK) and LDH with pyr uvate as substrate than did canine WBC. Canine WBC had significantly h igher activities of glucokinase (GK) and G1DH than did feline WBC. Fel ine WBC had unique characteristics of energy metabolism in that the ac tivities of the cytosolic enzymes under anaerobic conditions were sign ificantly higher than those in canine WBC. It therefore appears that t here are distinct differences in glucose metabolism in WBC between dog s and cats. WBC enzyme activities are considered to reflect the metabo lic state in the whole body of the animal. It is therefore suggested t hat changes in the activities of certain glycolytic enzymes in WBC may be useful as a diagnostic indicator in some types of metabolic diseas e in dogs and cats.