Lactic dehydrogenase isozymes in diploid and heteroploid cells

Abstract

In this study diploid embryonic lung cells from two different sources exhibit the same isozyme pattern for a period equal to approximately half of the life expectancy of these cells, A gradual diasppearance in the most anodal band is then found withe teh progressive aging of the cells. The heteroploid cells exhibit an isozyme pattern similar to the early passage of the diploid. The difference in the isozyme pattern between the heteroploid and early passages of the diploid cells, compared to the older passages of the diploid cells, cannot be explained by the total LDH concentration which is comparatively similar for all cells studied. A definite difference between the heteroploid and diploid cells was found in the amount of lactic acid produced; the diploid cells produced far greater quantities of lactic acid than the heteroploid cells. Malignant cells as well as well as embryonic cells usually exhibit a high rate glycolysis and accompanying lactate production. Diploid cells may resemble the embryonic cells from which they were derived in their lactate production. There are numerous exceptions to the high rate of glycolysis and lactate production usually found with malignant cells (13, 14). The low production of lactate found with the heteroploid cells in these studies may be another exception to the usual pattern. Further studies on the glycolytic and oxidative metabolism of the diploid and heteroploid cells are needed before any valid conclusions can be made.