Phenotypes of the Regan isoenzyme and identity between the placental D-variant and the Nagao isoenzyme.

Abstract

Summary We observed an unexpectedly high incidence of the D-variant placental phenotype in Regan isoenzyme-positive sera of cancer patients: Such D-variant-positive sera exhibit a high degree of inhibition by l-leucine, a phenomenon earlier associated with the Nagao isoenzyme. Unlike normal placentae, a diffuse phenotype of heat-stable alkaline phosphatase is usually noted in cancer sera containing Nagao isoenzyme.