Plasma phosphatidylcholine hydroperoxide-reducing activity in pregnant women.
Plasma glutathione peroxidase (PGPx) and apolipoproteins A-I, A-II, and B-100 reduce phosphatidylcholine hydroperoxide (PC-OOH) to its hydroxide (PC-OH). To elucidate the relative importance of the reduction pathways we developed a simple assay for measuring total PC-OOH-reducing activity. Human plasma was incubated with 1-palmitoyl-2-linoleoyl-phosphatidylcholine hydroperoxide and the time-dependent reduction was confirmed by its hydroxide formation, measured by reversed-phase high performance liquid chromatography. We determined the PC-OOH reducing activity in blood plasma of healthy men and women as 119 +/- 7 (n = 13, aged 27 to 45) and 101 +/- 4 microM/h (n = 5, aged 24 to 30), respectively. In addition, we also measured PC-OOH-reducing activity in the plasma of 53 pregnant women since they usually show hyperlipidemia or hyper-apolipoproteinemia. The average rate of PC-OOH reduction was 101 +/- 34 microM/hr. The PC-OOH-reducing activity was not affected by the addition of iodoacetamide, an inhibitor of PGPx, suggesting that the activity is due to apolipoproteins. A significant correlation between plasma reducing activity with apolipoprotein B-100 was observed (r = 0.290), but not with apolipoprotein A-I (r = 0.118). In pre-eclamptic patients, about an 8% decrease in plasma PC-OOH-reducing activity was observed as compared to the normal pregnancy group, although the decrease was not statistically significant.
Hayashida
K
K
Department of Obstetrics and Gynecology, Tokai University School of Medicine, Isehara, Kanagawa, Japan.
Iwasaki
K
K
Makino
T
T
Mashima
R
R
Yamamoto
Y
Y
Yoshimura
S
S
D000328:Adult; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D008297:Male; D010084:Oxidation-Reduction; D010713:Phosphatidylcholines / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000097:blood; D011247:Pregnancy / Q000097:blood*; D012016:Reference Values
D053299:Apolipoprotein B-100; D001055:Apolipoproteins B; D010713:Phosphatidylcholines; C057590:phosphatidylcholine hydroperoxide; D005979:Glutathione Peroxidase