The liver in human diabetes. Concentration of some induced enzymes.
Since glycogen overloading is one of the outstanding features of the diabetic liver, a series of investigations were undertaken to find an enzymatic explanation of this feature. Three groups of patients were studied: non diabetics submitted to liver biopsy during surgery (group A); non diabetics submitted to percutaneous liver biopsy (group B). In both these groups G-6-PDH, PK and MDH were assayed, all these being adaptive enzymes of intermediate metabolism. Results were expressed as muU/100 mg proteins. The significant finding of the comparison of these two groups was the low concentration of these enzymes in surgical biopsies. The depression was such that for G-6-PDH the concentration was more than 10 times less in surgical specimens as compared to percutaneous ones, whereas for PK it was almost 10 times less. In view of these findings no further surgically obtained biopsy material was used in this study. The third group (C) included insulin-dependent diabetics in good metabolic control from whom percutaneous liver biopsies were obtained for the assay of the same enzymes as above and in order to compare the results with those of group B. All three enzymes were diminished in diabetics, the difference being statistically significant for G-6-PDH and PK, not for MDH in view of the wide dispersion of the values found. Comparison and analysis of these results lead to the conclusion that in view of the low concentration of these enzymes in diabetics, glucose utilization in the liver cell must be presumed to be increased via other metabolic pathways.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D003920:Diabetes Mellitus / Q000201:enzymology* / Q000473:pathology; D004790:Enzyme Induction; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000096:biosynthesis; D006801:Humans; D008099:Liver / Q000201:enzymology* / Q000473:pathology; D008291:Malate Dehydrogenase / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D011770:Pyruvate Kinase / Q000096:biosynthesis
D008291:Malate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D011770:Pyruvate Kinase