[Activity and isoenzyme composition of lactate dehydrogenase and malate dehydrogenase in the blood and erythrocytes of newborn children with hemolytic disease].

Activities of lactate dehydrogenase (LDH) and NAD-dependent malate dehydrogenase (MDH) were considerably increased in blood serum of healthy children within the first 10 hrs after their birth. Content of LDH4 and LDH5 isoenzymes was increased, along with a decrease in LDH1 content, in blood serum. Differences in LDH isozyme spectra between blood serum and hemolysate in healthy newborns became more distinct within the perinatal period. In blood serum of newborns with hemolytic disease high activity of LDH and MDH was found immediately after birth. As distinct from healthy children, high content of LDH1 and very low concentrations of LDH4 and LDH5 were observed in blood serum of the impaired children within the perinatal period. The dissimilarity in LDH spectra became less distinct in blood serum and hemolysate of children with hemolytic disease. The composition of MDH isoenzymes was not distinctly altered in blood serum and hemolysate of both healthy and impaired newborn children within the perinatal period.