HEAT-STABLE ALKALINE PHOSPHATASE IN THE NORMAL FEMALE GENITAL ORGAN

The Regan isoenzyme, a heat-stable alkaline phosphatase, which has been thought to be derived only from cancer or the placenta, has been reported in non-cancer, non-pregnant patients. We performed histochemical studies to determine whether the heat-stable alkaline phosphatase exists in normal cells of the female reproductive organ. For this purpose, the heat-stability test and the L-phenylalanine inhibition test were used. Heat-stable and L-phenylalanine-sensitive alkaline phosphatase was found in normal cells of Muellerian duct origin, e.g., uterine cervical reserve cells, cervical columnar cells and epithelial cells of the endometrial surface. Our findings suggest that heat-stable alkaline phosphatase, such as the Regan enzyme, may be produced by normal cells of Muellerian duct origin.