Glutathione S-transferases and esterases in placenta after normal and pre-eclamptic pregnancies.
Severe pre-eclampsia reduced significantly (P<0.05) by 68+/-6 per cent (mean+/-sem, n=10) the maximal velocity (V(max)) and, consequently, reduced significantly by 60+/-7 per cent the catalytic efficiency (C(E)) of placental glutathione transferase pi, assayed with ethacrynic acid. Mild and severe pre-eclampsia reduced significantly by 82+/-5 per cent (mean+/-sem, n=5) and by 41+/-5 per cent (mean+/-sem, n=10), respectively, the V(max)and, consequently, reduced significantly by 72+/-7 and by 33+/-13 per cent, respectively, the C(E)of esterase, assayed with p-nitrophenyl acetate. Furthermore, severe pre-eclampsia increased significantly by 296+/-78 per cent the Michaelis-Menten constant (K(m)) of total GST, assayed with chlorodinitrobenzene and, consequently, decreased significantly the C(E)by 83+/-3 per cent. On the other hand, the concentrations of total and non-protein thiols did not change significantly in placental homogenates from patients with mild or severe pre-eclampsia compared to normal pregnancies. These findings would indicate a decreased capacity of the glutathione transferases and esterase detoxification systems to protect the fetus from drugs prescribed to pregnant women suffering pre-eclampsia, mainly in the severe phase.
del Carmen Terrones Saldívar
M
M
Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, 20100 Aguascalientes, Ags, Mexico.
Juárez
F J
FJ
Viramontes
J L
JL
Rodríguez Vázquez
M L
ML
Posadas del Río
F A
FA
D000328:Adult; D004950:Esterases / Q000378:metabolism*; D005260:Female; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D010920:Placenta / Q000201:enzymology*; D011225:Pre-Eclampsia / Q000201:enzymology* / Q000503:physiopathology; D011247:Pregnancy
D005982:Glutathione Transferase; D004950:Esterases