A Study on the Property of LDH Isoenzymes of Rabbits

Abstract

The present paper reported on the nature of pyruvate inhibition of LDH isoenzymes with and without urea. The crude LDH isoenzymes were prepared from rabbit heart muscle for the H-LDH and from rabbit psoas muscle for the M~LDH, with the following conclusions. 1. It is possible to obtain 4~5 fold purification of the LDH isoenzymes from rabbit heart and psoas muscles only with ammonium sulfate fractionation and DEAE-cellu1eJse treatment. 2. In electrophoresis a new method of staining is proposed as follows; after electrophoresis with agarose gel a cellulose acetate strip, presoaked in the staining mixture, is overlapped on top of the agarose gel, followed by incubation and densitometry. In so doing, a kinetic study on the LDH isoenzymes could be possible through formazan staining, instead of UV spectrophotometry. 3. The H-LDH isoenzyme activity is more markedly inhibited than the M-LDH isoenzyme by pyruvate. 4. Under the presence of urea, pyruvate inhibition of H-LDH isoenzyme decreases, while that of M-LDH isoenzyme increases.