Glutathione peroxidase, glutathione reductase, glutathione S-transferase, and γ-glutamyltranspeptidase activities in the human early pregnancy placenta

Abstract

GSH peroxidase, GSSG reductase, GSH S-transferase, and γ-glutamyltranspeptidase activities were measured in the supernatant of 13 human early pregnancy placenta homogenates. From measurements of GSH peroxidase activity with both H 2O 2 and cumene hydroperoxide as second substrate it was deduced that immature placenta contains only the Sedependent form. All the specimens investigated exhibited GSSG reductase and γ-glutamyltranspeptidase activities. GSH S-transferase activity was noted only using 1-chloro-2,4-dinitrobenzene as electrophilic substrate, while no detectable activity was found with 1,2-dichloro-4-nitrobenzene, 1,2-epoxy-3-( p-nitrophenoxy) propane, and p-nitrobenzylchloride. It is concluded that human placenta is equipped, from early pregnancy, with the enzymatic systems which are involved in GSH-mediated cellular detoxication and in preserving the integrity of the sulfhydryl status of the cells.