title: Lactate dehydrogenase isoenzyme pattern in sera of patients with malignant diseases.
abstract: Total lactate dehydrogenase (LDH; EC 1.1.1.27) activity and the percentage distribution of LDH isoenzymes were determined in 127 patients with malignant diseases. A shift in the isoenzyme patterns was observed toward the M-type, with an increase in the percentage of LDH-4 and LDH-5 isoenzymes and a slight increase in total LDH activity of all patients. Serum samples from 68 of the patients contained an abnormal isoenzyme of LDH, "LDH-1 ex," that, on agarose gel electrophoresis at pH 8.6, migrated between albumin and LDH-1 isoenzyme. Chemotherapy, radiotherapy, or surgical removal of the tumor was accompanied by disappearance of this abnormal isoenzyme. The heat stability of LDH-1 ex isoenzyme appears to be similar to that of LDH-1 but greater than that of the other LDH isoenzymes. Statistical analysis of these data demonstrated a significant correlation between malignancy and the appearance of LDH-1 ex isoenzyme (P less than 0.001). In contrast, the relationship between LDH-1 ex isoenzyme and metastasis or anatomical location of the malignancy is not statistically important (P less than 0.1).
authors.affiliation: First Department of Internal Medicine, General State Hospital Agios Andreas, Patras, Greece.
authors.forename: E E
authors.initials: EE
authors.lastname: Giannoulaki
authors.forename: D L
authors.initials: DL
authors.lastname: Kalpaxis
authors.forename: C
authors.initials: C
authors.lastname: Tentas
authors.forename: P
authors.initials: P
authors.lastname: Fessas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004355:Drug Stability; D004587:Electrophoresis, Agar Gel; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000201:enzymology* / Q000628:therapy; D012016:Reference Values
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase