Abstract
AIM: To investigate the relationship between lactate dehydrogenase (LDH) activity or LDH isoenzyme patterns and the pathogenesis of colorectal cancer. METHODS: Activities of tissue LDH and LDH isoenzyme patterns in 16 patients with colorectal cancer were assayed using spectrophotometric procedures and agarose gel electrophoresis, respectively. RESULTS: The total and specific activities of LDH were significantly higher in colorectal cancer tissues than those in adjacent noncancerous tissues (P < 0.001). The LDH isoenzyme pattern was also different from that in the control. The percentage of LDH5 doubled and the ratio of LDH4 + LDH5/LDH1 + LDH2 was 3.6 ± 1.4 in cancer tissue, significantly greater than in the control. CONCLUSIONS: The increased LDH activity in colorectal cancer tissues resulted mainly from the increased LDH5, suggesting that the alteration of LDH activity and isoenzyme patterns were related to the pathogenesis of colorectal cancer.