Respiratory and Calcium Transport Functions of Mitochondria Isolated from Normal and Transformed Human Lymphocytes1

Methods have been developedto isolatemitochondriafrom small amounts of normal and leukemic human lymphocytes obtained from small volumes of circulating blood. Mitochondrial respiratory functions were measured by polarographic tech niques, and active calcium uptake was measured by a spectro photometric procedure utilizing the calcium-sensitive dye mu rexide. The results indicate that the rates of active oxygen consumption of normal human lymphocyte mitochondria are very low in comparison to values obtained from a number of animal tissue sources. Mitochondria extracted from the lym phocytes of leukemic patients and from cultured, and phyto hemagglutinin-transformed human lymphocytes exhibited higher respiratory rates than did normal controls. Although respiratory rates were relatively low in all preparations, the efficiency of energy coupling (ADP:O, ratio of nmol of adeno sine diphosphate phosphorylated to nanoatoms of 02 con sumed) was within normal limits. The mitochondria extracted from leukemic, cultured, and phytohemagglutinin-transformed lymphocytes exhibited high rates of respiratory substrate-sup portedcalciumuptakecomparedto controls.