Alkaline phosphatase activity in relation to LDH5 (L-lactate: NAD+ - oxidoreductase, E.C.1.1.1.27) in patients with precancerous conditions of the endometrium.

We investigated the serum activity of the fifth fraction of L-lactate: NAD-oxidoreductase (E.C.1.1.1.27) and serum alkaline phosphatase activity prior to diagnostic curettage in patients with abnormal and atypical endomertial hyperplasia. We also determined them in 75 patients with carcinoma of the endometrium, 80 patients with glandular cystic endometrial hyperplasia and a "normal" control group of 70 patients. In the statistical evaluation we found a significantly high incidence of low AP activity and elevated LDH5 in the group of patients with glandular cystic endometrial hyperplasia, as well as in patients with precancerous lesions of the endometrium and carcinoma of the endometrium. The findings raise the question of whether these changes in the serum activity of the given enzymes are only a response to a given hormonal modulation.