HISTOCHEMICAL STUDY OF OXIDATIVE ENZYMES IN VERTEBRATE MUSCLES

Abstract

A histochemical study was carried out on oxidative enzymes, succinic dehydrogenase, diphosphopyridine nucleotide (DPN)-dependent dehydrogenases (lactic, malic, α-glycerophosphate, glutamic, and β-hydroxybutyric dehydrogenases), DPNH-diaphorase, triphosphopyridine nucleotide (TPN)-dependent dehydrogenases (isocitrate, and glucose-6-phosphate dehydrogenase) and TPNH-diaphorase on various kinds of vertebrate muscles. The results obtained were as follows: 1. Most of the mammalian striated muscle fibers fell into three types following a histochemical demonstration of oxidative enzyme reaction: Small red muscle fibers showed higher activities of oxidative enzymes, while large white fibers lower activities and the third type of fibers, "medium fiber" which were intermediate in size showed activities between red and white muscle fibers. 2. The intrafusal fibers of mammalian muscle spindles are classified into three types by oxidative enzyme reactions, i.e., red intrafusal fibers, medium intrafusal fibers and white intrafusal fibers. 3. Regarding birds, chicken muscle was composed of three types of fibers, while pigeon and lovebird muscles displayed two types of fibers. 4. Reptile and amphibian muscle fibers were classed as small red fibers showing higher activities, medium fibers moderate activities and white fibers lower activities. 5. Fish red muscle was composed only of red fibers, and the white muscle of white fibers. The transitional part of red and white muscles, revealed three types of fibers. 6. Generally, succinic dehydrogenase, lactic dehydrogenase, malic dehydrogenase, α-glycerophosphate dehydrogenase showed a higher activity, DPNH-diaphorase, TPNH-diaphorase a moderate activity, glutamic dehydrogenase, isocitrate dehydrogenase a lower activity and β-hydroxybutyric dehydrogenase and glucose-6-phosphate dehydrogenase a trace or nonactivity in most vertebrate striated muscles.