Effect of cadmium on some enzyme activities in first-trimester human placentae.
Explants from first-trimester placentae obtained from non-smoking women were incubated with doses of 0, 0.75, 1.5, 3, 6 and 12 micrograms of cadmium (Cd) as CdCl2 for 6 or 24 h. At the end of the incubation period, the activities of placental aryl hydrocarbon hydroxylase (AHH) (a phase I enzyme), quinone reductase (QR) and catecholamine-O-methyltransferase (COMT) (both phase II enzymes) and glucose-6-phosphate dehydrogenase (G-6-PD) were determined. Cd at low dose levels increased significantly the activities of placental phases I and II enzymes in a time- and dose-dependent manner. Of the first 3 enzymes, only AHH showed a biphasic response for the two time periods, with the activities of QR and COMT continually increasing at all the dose levels tested for the two incubation periods. However, the G-6-PD activity was inhibited at all the dose levels of Cd, the effect being very drastic after exposure to 0.75 ppm Cd for both incubation periods.
Boadi
W Y
WY
Department of Food Engineering and Biotechnology, Technion--Israel Institute of Technology, Haifa.
Urbach
J
J
Brandes
J M
JM
Yannai
S
S
D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism*; D002104:Cadmium / Q000494:pharmacology*; D002394:Catechol O-Methyltransferase / Q000378:metabolism; D046508:Culture Techniques; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism*; D006801:Humans; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism*; D010920:Placenta / Q000187:drug effects* / Q000201:enzymology; D011247:Pregnancy; D011261:Pregnancy Trimester, First
D002104:Cadmium; D005954:Glucosephosphate Dehydrogenase; D001189:Aryl Hydrocarbon Hydroxylases; D016660:NAD(P)H Dehydrogenase (Quinone); D002394:Catechol O-Methyltransferase