The effect of carcinoma of the cervix on the L-lactate-nicotinamide-adenine dinucleotide oxidoreductase activity in vaginal aspirates.

Lactate dehydrogenase (L-lactate-NAD+ oxidoreductase; EC 1.1.1.27) has been assayed in saline extracts of vaginal aspirates obtained from patients with carcinoma in situ and from patients with clinically detectable invasive carcinoma of the cervix. Taking premenopausal and postmenopausal patients separately, significant differences were found between the aspirate lactate dehydrogenase activities obtained from patients with carcinoma in situ and the activities obtained from patients with invasive carcinoma; generally higher activities were obtained from the latter. With the exception of postmenopausal patients with carcinoma in situ, aspirate enzyme activities obtained from both groups of patients were significantly different from those obtained from normal women. Significantly higher lactate dehydrogenase activity was found in aspirates from patients for whom histology showed the presence of an adenocarcinoma or certain highly malignant cell types. Treatment by radium insertion usually resulted in a fall total lactate dehydrogenase activity. Significant differences between groups were found for the proportions of single lactate dehydrogenase isoenzymes in a few instances but no significant difference in overall isoenzyme distribution was found.