title: Patterns of lactate dehydrogenase isoenzymes 1 and 2 in serum of patients performing an exercise test.
abstract: Values for total lactate dehydrogenase (LD, EC 1.1.1.27) activity and LD isoenzymes were determined in serum from 56 patients and 40 healthy subjects before and 24, 48, and 72 h after they performed an exercise test. The mean (for all four times) total LD activity concentration and proportion of LD-2 were within the normal range for all 96 subjects. Mean LD-1 values for serum, although within the normal range in all subjects, were significantly higher in patients with positive exercise test results than in subjects with negative results: 75 (SD 12) U/L in 35 patients with ST depression greater than 2 mm; 63 (SD 14) U/L in 16 patients with ST depression of 1-2 mm; 43 (SD 11) U/L in subjects with negative test results, by 48 h after the test. The LD 1:2 ratio was also markedly higher in the group of patients with positive test exercise results, especially in those with ST depression greater than 2 mm (1.02, SD 0.06), compared with those subjects with negative results (0.60, SD 0.04). A similar trend was also found 24 and 72 h after the exercise test. We conclude that exercise-myocardial ischemia may lead to an increased LD 1:2 ratio in serum, and demonstrate a correlation between the degree of ischemia and the LD 1:2 ratio. Determination of the LD 1:2 ratio, even in the presence of normal total LD activity, may assist in the clinical evaluation of patients performing an exercise test.
authors.affiliation: Department of Medicine "A", Israel and Ione Massada Center for Heart Diseases, Petah Tikva, Israel.
authors.forename: Z
authors.initials: Z
authors.lastname: Rotenberg
authors.forename: I
authors.initials: I
authors.lastname: Weinberger
authors.forename: A
authors.initials: A
authors.lastname: Sagie
authors.forename: J
authors.initials: J
authors.lastname: Fuchs
authors.forename: E
authors.initials: E
authors.lastname: Davidson
authors.forename: O
authors.initials: O
authors.lastname: Sperling
authors.forename: J
authors.initials: J
authors.lastname: Agmon
mesh_terms: D000328:Adult; D003327:Coronary Disease / Q000201:enzymology*; D004588:Electrophoresis, Cellulose Acetate; D005080:Exercise Test; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012015:Reference Standards
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase