SUBFRACTIONS OF LACTATE DEHYDROGENASE OF THE RAT

Abstract
A survey of the lactate dehydrogenase (LDH) isozymes of 20 organs and tissues of the rat revealed a total of nine fractions exhibiting LDH activity after starch gel electrophoresis. Of the nine LDH fractions, eight were found in testis and lymph node, while the ninth fraction was unique to kidney. The occurrence of LDH fractions in excess of the usual five LDH isozymes is accounted for by two alternate proposals. One proposal is an extension of the present tetramer postulate of LDH structure, while the other is a consideration of the significance of heterozygosity in the albino rats employed in the study. Both hypotheses are plausible and should be considered in future studies of isozymes.