title: Lactate dehydrogenase isoenzymes in diabetic patients.
abstract: Lactate dehydrogenase (LDH) isoenzyme profiles in human platelets and the sera of patients with type I and II diabetes mellitus and vascular complications, as well as normal subjects were measured utilizing a recently established, modified micromethod. LDH-3 was the predominating species in platelets (37.5 +/- 3.0%), with LDH-2, 1, 4 and 5 following in decreasing order of concentration. The LDH-3/LDH-4 ratio in platelets varied from 6.2 to 1.38. Type I and type II diabetic patients with vascular complications showed a significantly higher ratio for LDH-3/LDH-4 (3.99 +/- 1.20 for DM I, 2.16 +/- 0.25 for DM II patients) than the mean ratio for normal subjects (1.14 +/- 0.08). This platelet-specific LDH isoenzyme pattern may be the result of frequent in vivo platelet-vessel wall interactions in the diabetic patients whose platelets are known to be hyperaggregable in in vitro test systems. Since non-diabetic patients patients with vascular complications also displayed a similarly elevated LDH-3/LDH-4 ratio, a wider classification is preferable, although the measurement of the LDH isoenzyme pattern will be helpful in assessing diabetic vascular complications.
mesh_terms: D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000201:enzymology; D002848:Chromatography, DEAE-Cellulose; D003920:Diabetes Mellitus / Q000201:enzymology*; D003925:Diabetic Angiopathies / Q000201:enzymology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D008875:Middle Aged
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase