Lactate dehydrogenase and its isoenzymes, creatine phosphokinase and aldolase in different bovine muscles

Abstract

Histochemical studies and quantitative assays were undertaken on bovine cardiac muscle, chewing muscles, muscles involved partly in chewing or partly in respiration, muscles of the trunk and the extremities and smooth muscles. Activities of total lactate dehydrogenase, creatine phosphokinase and 1,6-diphosphate-aldolase, as well as lactate dehydrogenase isoenzyme determinations were carried out. Bovine cardiac muscle showed a well-developed oxidative enzyme system and very low glycolytic enzyme activities. Histochemically it demonstrated a uniform distribution of the enzymes. Similar findings were obtained in bovine chewing muscles and it was suggested that these muscles are composed of βR fibres only. The group of muscles involved partly in chewing or partly in respiration showed high oxidative enzyme activities and a moderately developed glycolytic enzyme system. These muscles seem to be composed of αR fibres or of a mixture of αR and βR fibres. The muscles of the trunk and the extremities have a highly developed glycolytic enzyme system and appear to be composed mainly of αR and αW fibres. The smooth muscles appeared to have a less developed oxidative enzyme system than cardiac muscle or chewing muscles, but a glycolytic enzyme activity close to that of muscles partly involved in chewing or respiration. Thus the aerobic and glycolytic metabolism of the smooth muscles appears to be specially adapted to their physical activity.