Increased biological oxidation and reduced anti-oxidant enzyme activity in pre-eclamptic placentae.
Oxidative stress occurs when cellular levels of reactive oxygen species exceed anti-oxidant capabilities and has been implicated in the pathogenesis of pre-eclampsia. In this study we have examined the tissue levels of endogenous anti-oxidant proteins (superoxide dismutase, glutathione peroxidase, thioredoxin reductase and thioredoxin) and the level of lipid and protein oxidation in placental samples from normal and pre-eclamptic pregnancies. Pre-eclamptic tissue homogenates demonstrated significantly increased levels of lipid peroxidation (20.68 +/- 7.811 microM protein versus 5.33 +/- 4.03 microM/mg protein, P < 0.001) and a trended increase in protein carbonyl concentration (248.1 +/- 97.71 units/mg protein versus 209.7 +/- 82.6 U/mg protein) when compared to controls. The levels and activities of the anti-oxidant proteins superoxide dismutase (2.48 +/- 0.6 U/mg protein versus 2.02 +/- 0.51 U/mg protein, P <0.02), thioredoxin reductase (19.25 +/- 9.81 U/mg protein versus 13.02 +/- 5.66 U/mg protein,P = 0.02), thioredoxin (107.00 +/- 18.11 ng/mg protein versus 91.12 +/- 21.18 ng/mg protein, P = 0.02) and glutathione peroxidase (17.33 +/- 6.63 mmol/min/mg protein versus 11.50 +/- 3.11 mmol/min/mg, P < 0.02) were all found to be significantly reduced when comparing pre-eclamptic placental tissue homogenates to gestational age-matched control placentae from non-pre-eclamptic pregnancies. The results of this study demonstrate a decreased enzymatic anti-oxidant capacity and increased oxidation in placental tissue from pre-eclamptic women, which may contribute to the pathogenesis of this complex disorder.
Vanderlelie
J
J
School of Health Science, Griffith University Gold Coast Campus, Parklands Drive, Southport, QLD 9726, Australia.
Venardos
K
K
Clifton
V L
VL
Gude
N M
NM
Clarke
F M
FM
Perkins
A V
AV
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D010088:Oxidoreductases / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology* / Q000473:pathology; D011225:Pre-Eclampsia / Q000201:enzymology* / Q000473:pathology; D011247:Pregnancy; D013482:Superoxide Dismutase / Q000378:metabolism; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism
D000975:Antioxidants; D013879:Thioredoxins; D010088:Oxidoreductases; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D013880:Thioredoxin-Disulfide Reductase