Enzymatic development of the human fetus; the isozyme of lactic dehydrogenase in the developing human fetal tissues.

Abstract

Summary Studies on LDH-isozyme during development of the human fetus were undertaken. In the heart and liver during the early fetal life, the activity was found to be predominant in the LDH-3 area. In the heart the predominancy of LDH-3 area was found to continue throughout the fetal life, while in the liver it decreased and LDH-5 region increased at 5 months of gestation. A decrease in the activity of LDH-3 in the heart was found to occur after birth. Changes in LDH isozyme pattern in the skeletal muscle were found to be approximate to those in the liver. No remarkable changes in the isozyme pattern were shown in the brain and kidney. Subsequently, changes in H-LDH and M-LDH activity level, as an activity unit of LDH function, were observed. In the heart, a rise of the activity of H-LDH as well as M-LDH was found to occur during the fetal periods and it was followed by increases in only the H-LDH after birth. In the liver and muscle, increases only in the M-LDH activity were observed during development. In the kidney, a rise of LDH activity was found to occur in both types of LDH. In the brain, no remarkable changes were found in either of the LDH types.