Oxidative stability of low density lipoproteins and vitamin E levels increase in maternal blood during normal pregnancy

Abstract

In 24 healthy pregnant women, parameters related to the oxidative stability of low density lipoproteins (LDL) were determined at three times during pregnancy and shortly after delivery. The fatty acid composition of plasma phospholipids (PL) and the plasma concentrations of vitamin E, vitamin A, and beta-carotene were assessed in the same samples. Total triglyceride (TG), total cholesterol, LDL-cholesterol, and high density lipoprotein (HDL)-cholesterol concentrations were also determined. The length of the lag phase of isolated LDL challenged with Cu2+ ions significantly increased with the progression of pregnancy. The oxidation rate and the amount of conjugated dienes formed increased and reached a maximum at 29-37 wk of pregnancy. Total TG, cholesterol, and LDL-cholesterol reached a maximum in the third trimester of pregnancy. beta-Carotene remained stable, vitamin A decreased, and vitamin E significantly increased throughout pregnancy. Vitamin E plasma concentration correlated positively with the length of the lag phase. The increased levels of vitamin E could contribute to the higher resistance of LDL toward oxidation with progressing gestation, measured by the prolonged lag phase. Furthermore, vitamin E plasma levels correlated positively with TG concentration but not with LDL-cholesterol. The level of polyunsaturated fatty acids in PL decreased with the progression of pregnancy. No correlation was found between the fatty acid composition of plasma PL, nor with the cholesterol concentration, and the parameters studied related to the oxidative stability of LDL. The major finding of this study is the increased oxidative resistance of LDL with progressing gestation.

Differential effects of docosahexaenoic acid on preterm and term placental pro-oxidant/antioxidant balance

“…The activity of the primary enzymatic antioxidants (catalase, superoxide dismutase and glutathione reductase) increases over pregnancy, while that of placental glutathione peroxidase remains unchanged (Qanungo & Mukherjea 2000). Conversely, serum or plasma levels of non-enzymatic antioxidants, including vitamin A (De Vriese et al 2001) and b-carotene (Oostenbrug et al 1998), decrease throughout pregnancy, while levels of a-tocopherol increase (Oostenbrug et al 1998, De Vriese et al 2001. Together these gestational changes in antioxidant capacity appear to place the preterm newborn at an increased risk of ROSinduced injury (Shah & Shah 2009).…”

Lowered serum n-3 polyunsaturated fatty acid (PUFA) levels predict the occurrence of postpartum depression: Further evidence that lowered n-PUFAs are related to major depression

“…The lipids were separated by thin layer chromatography on rhodamine-impregnated silica gel plates using petroleum ether (bp 60-80 jC; Merck Belgolab, Overijse, Belgium) / acetone 85:15 as mobile phase (Christophe and Matthijs, 1967). The PL and CE fraction were scraped off and the fatty acids converted into methyl esters by transesterification with 2 mL of a mixture of methanol:benzene:HCl (aqueous, 12N) (80:20:5) (De-Vriese et al, 2001). After cooling and adding 2 mL of water, fatty acid methyl esters were extracted with petroleum ether (bp 40-60 jC), evaporated to dryness under a nitrogen flow at a temperature not exceeding 40 jC, and analysed by temperature programmed capillary gas chromatography (Varian Model 3500, Walnut Creek, CA, USA) on a 30 m  250 Am (L  ID)  0.2Am df column Restek 2330 (Restek Corp., Bellefonte, PA, USA).…”

Relationship between plasma fatty acid profile and antioxidant vitamins during normal pregnancy

“…Hyperlipidemia, characteristic of normal pregnancy during late gestation, is associated with enhanced oxidative stress (Uotila et al, 1991;Morris et al, 1998;Toescu et al, 2002), although this effect seems to be counteracted by increased oxidative resistance of LDL (De Vriese et al, 2001). The latter probably occurs due to the enhanced level of vitamin E, although other antioxidant vitamins, like bcarotene and vitamin A, remain, respectively, stable or decreased during normal pregnancy (De Vriese et al, 2001).…”

“…The latter probably occurs due to the enhanced level of vitamin E, although other antioxidant vitamins, like bcarotene and vitamin A, remain, respectively, stable or decreased during normal pregnancy (De Vriese et al, 2001). Plasma levels of a-and g-tocopherols have consistently been shown to be reduced in the cord blood of normal newborns and in preterm infants compared to either maternal or normal adult levels (Muller, 1994;Yeum et al, 1998;Kiely et al, 1999).…”