Relationship between the maturation index and lactate dehydrogenase activity in human vaginal epithelium

Simultaneous determinations of LDH activity in the vaginal epithelium and the maturation index of the vaginal smear were performed for 7 postmenopausal women receiving estrogen therapy and for 4 premenopausal women. Of the premenopausal women, 1 was receiving cyclic estradiol valerate-levo-norgestrel therapy; the others were menstruating regularly and had no hormone therapy. A good correlation was found between the strength of the estrogen therapy and LDH activity. In general, a positive correlation was found between a high level of LDH activity and a shift to the right in the maturation index. Where inflammation occurred, the LDH activity reflected the estrogen effect, whereas the maturation index did not do so.