HISTOCHEMICAL STUDIES ON THE LIPID REQUIREMENT FOR THE OXIDATIVE ENZYME ACTIVITIES : II. STUDIES ON THE EFFECTS UPON THE OXIDATIVE ENZYME ACTIVITIES OF PHOSPHOLIPIDS, Co Q AND β-LIPOPROTEIN

Abstract

(1) It has been made clear that the loss of phospholipids from cells by alcohol or some of the other organic solvents used in the histological procedures generally causes the reduction or disappearance of the activities of some oxidative enzymes, such as DPNH diaphorase, TPNH diaphorase, succinic dehydrogenase, lactic dehydrogenase, malic dehydrogenase, β-hydroxybutyric dehydrogenase and other oxidative enzymes that are in close relation to mitochondria, and that the reduced or lost activities of these oxidative enzymes can be restored by phospholipids, Co Q group or β-lipoprotein. (2) The lipid requirement of a group of the oxidative enzymes proved to be closely connected with the ultrastructural localization of the enzymes. (3) On the basis of the lipid requirement of the oxidative enzymes new improved methods have been established for the histochemical demonstrations of cytochrome oxidase, DPNH diaphorase, TPNH diaphorase, succinic dehydrogenase, lactic dehydrogenase, malic dehydrogenase, β-hydroxybutyric dehydrogenase and glutamic dehydrogenase. (4) In these new methods the non-specific reduction of tetrazolium salt was not seen even at high alkaline pH (about 9.3). These new histochemical methods are thus much better than the methods in use at present.