Changes in activity of enzymes related to glycolysis, gluconeogenesis and lipogenesis in placentae from diabetic women.
The activity of enzymes with a regulatory function in the pathways of glycolysis, gluconeogenesis and NADP-generation was investigated in 50 placentae from normal pregnancies and deliveries, 23 placentae from women with gestational diabetes, and 12 placentae from insulin-dependent patients. In placentae from the gestational diabetic group, the activity of pyruvate kinase and of NADPH-generating enzymes was raised and the activity of enzymes connected to glucogenesis was unchanged. These alterations were attributed to the oversupply of glucose and insulin to morphologically normal and well-oxygenated placental tissue. In the placentae from the insulin-dependent group, the activity of pyruvate kinase was reduced, the activity of NADPH-generating enzymes was enhanced and the activity of those related to the gluconeogenesis was unchanged. It is suggested that this pattern of enzyme changes reflects a reduction in the glycolytic capacity in these placentae, which may be due to inhibition by products of enhanced fatty acid oxidation in diabetes, amino acids and/or by long-term anoxia as a result of uteroplacental circulatory disturbances. The possible relation of reduced energy-forming capacity of the placenta in diabetes to its transport function is discussed.
D001219:Aspartate Aminotransferases / Q000378:metabolism; D001724:Birth Weight; D003922:Diabetes Mellitus, Type 1 / Q000201:enzymology*; D005260:Female; D005943:Gluconeogenesis; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D007231:Infant, Newborn; D050356:Lipid Metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010734:Phosphogluconate Dehydrogenase / Q000378:metabolism; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000201:enzymology*; D011770:Pyruvate Kinase / Q000378:metabolism
D009249:NADP; D008291:Malate Dehydrogenase; D010734:Phosphogluconate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D001219:Aspartate Aminotransferases; D011770:Pyruvate Kinase