Isoprostanes,Prostaglandins and Tocopherols in Pre-eclampsia,Normal Pregnancy and Non-pregnancy

This study is designed to evaluate whether oxidative stress and inflammation are involved in severe pre-eclampsia compared to normal pregnancy and non-pregnancy. We have measured plasma and urinary levels of 8-iso-PGF_2α, a major isoprostane as an indicator of oxidative stress; plasma and urinary 15-keto-dihydro-PGF_2α, a major metabolite of cyclooxygenase-catalysed PGF_2α as an indicator of inflammatory response, and plasma -α-and -γ-tocopherol in 18 pre-eclamptic, 19 normal pregnancy and 20 non-pregnant women. Pregnant women had significantly higher levels of 8-iso-PGF_2α and PGF_2α metabolite as compared to the non-pregnancy. Levels of 8-iso-PGF_2α in the pre-eclamptic women did not differ from the normal pregnancy but PGF_2α metabolite levels were significantly higher in normal pregnancy. On the other hand, γ-tocopherol levels were significantly lower in pre-eclampsia than normal pregnancy. In contrast, the concentration of α-tocopherol was very similar between the groups. α-and γ-tocopherol levels were significantly lower in pregnancy compared to non-pregnancy. Although no direct evidence of oxidative stress and inflammatory response was observed in severe pre-eclampsia, a reduction of γ-tocopherol suggests the possible precedence of oxidative stress in this condition. Higher levels of isoprostanes and prostaglandin metabolite in late pregnancy suggest the importance of both free radicals and cyclooxygenase-catalysed oxidation products in normal biological processes of pregnancy.     

Time course and attenuation of ischaemia-reperfusion induced oxidative injury by propofol in human renal transplantation

Abstract

Ischaemia-reperfusion injury resulting from interruption and restoration of blood flow might be related to free radical mediated oxidative stress and inflammation, and subsequently to post-surgery related complications. We studied the impact of renal transplantation on oxidative stress and inflammation by measuring F₂-isoprostanes and prostaglandin F_2α, respectively, during transplantation and post-surgery. Additionally, due to earlier observations, two dissimilar anaesthetic agents (thiopentone and propofol) were compared to determine their antioxidative capacity rather than their anaesthetic properties. Blood samples were collected before, post-intubation, immediately, 30, 60,120, 240 min, and 12 and 24 h after reperfusion. Oxidative stress and inflammatory response were detected by measuring 8-iso-PGF_2α (a major F₂-isoprostane and a biomarker of oxidative stress) and 15-keto-dihydro-PGF_2α (a major metabolite of PGF_2α and a biomarker of COX-mediated inflammatory response), respectively. Reperfusion of the transplanted graft significantly increased plasma levels of 8-iso-PGF_2α. PGF_2α metabolite levels, although elevated, did not reach statistical significance. In addition, significantly lower levels of 8-iso-PGF_2a were observed in the propofol group compared to the thiopentone group. Together, these findings underline an augmented oxidative stress activity following an inflammatory response after human renal transplantation. Furthermore, propofol a well-known anaesthetic, counteracted oxidative stress by lowering the formation of a major F₂-isoprostane.     

Serum selenium predicts levels of F2-isoprostanes and prostaglandin F2α in a 27 year follow-up study of Swedish men

Low concentrations of selenium (Se) predict mortality and cardiovascular diseases in some populations. The effect of Se on in vivo indicators of oxidative stress and inflammation, two important features of atherosclerosis, in human populations is largely unexplored. This study investigated the longitudinal association between serum selenium (s–Se) and a golden standard indicator of oxidative stress in vivo (8-iso-prostaglandin F_2α, a major F₂-isoprostane), an indicator of cyclooxygenase (COX)-mediated inflammation (prostaglandin F_2α), high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6) and serum amyloid A protein (SAA) in a follow-up study of 27 years. The s–Se was measured in 615 Swedish men at 50 years of age in a health investigation. The status of oxidative stress and inflammation was evaluated in a re-investigation 27 years later by quantification of urinary 8-iso-PGF_2α and 15-keto-dihydro- PGF_2α (a major metabolite of PGF_2α) and serum hsCRP, SAA and IL-6. Men in the highest quartile of s–Se at age 50 had decreased levels of 8-iso-PGF_2α compared to all lower quartiles and decreased levels of PGF_2α compared to all lower quartiles at follow-up. These associations were independent of BMI, diabetes, hyperlipidemia, hypertension, smoking, α-tocopherol and β-carotene at baseline. The s–Se was not associated with hsCRP, SAA or IL-6 at follow-up. In conclusion, high concentrations of s–Se predict reduced levels of oxidative stress and subclinical COX-mediated (but not cytokine-mediated) inflammation in a male population. The associations between Se, oxidative stress and inflammation, respectively, might be related to the proposed cardiovascular protective property of Se.     

Severe Vitamin E deficiency exacerbates acute hyperoxic lung injury associated with increased oxidative stress and inflammation

Hyperoxia causes acute lung injury along with an increase of oxidative stress and inflammation. It was hypothesized that vitamin E deficiency might exacerbate acute hyperoxic lung injury. This study used α-tocopherol transfer protein knockout (α-TTP KO) mice fed a vitamin E-deficient diet (KO E(-) mice) as a model of severe vitamin E deficiency. Compared with wild-type (WT) mice, KO E(-) mice showed a significantly lower survival rate during hyperoxia. After 72 h of hyperoxia, KO E(-) mice had more severe histologic lung damage and higher values of the total cell count and the protein content of bronchoalveolar lavage fluid (BALF) than WT mice. IL-6 mRNA expression in lung tissue and the levels of 8-iso-prostaglandin F_2α (8-iso-PGF_2α) in both lungs and BALF were higher in KO E(-) mice than in WT mice. It was concluded that severe vitamin E deficiency exacerbates acute hyperoxic lung injury associated with increased oxidative stress or inflammation.     

Oxidative stress early in pregnancy and pregnancy outcome

The objectives of this study were to determine whether oxidative stress early in pregnancy influenced pregnancy outcome. A combination of assays were used for exogenous and endogenous anti-oxidants together with two well accepted biomarkers for oxidative stress, the urinary excretion of 8-iso-PGF_2α (a biomarker marker for lipid oxidation, n=508) and 8-oxo-7,8 dihydro-2 deoxyguanosine (8-OHdG, a biomarker for DNA oxidation, n=487). The two biomarkers tracked different pregnancy outcomes. Isoprostanes were associated with an increased risk of pre-eclampsia and a decreased proportion of female births. In contrast, 8-OHdG tracked lower infant birthweight and shortened gestation duration. Birth defects were associated with low levels of 8-OHdG.     

Allergen-induced formation of F2-isoprostanes in a murine asthma model identifies oxidative stress in acute airway inflammation in vivo

F₂-isoprostanes have been associated with various forms of oxidant stress. The levels of F₂-isoprostanes in a murine asthma model were studied both in situ and in vivo and further investigated whether the formation of F₂-isoprostanes was associated with increased ovalbumin (OVA)-induced airway inflammation after a 17-day (OVA-17) or a 24-day (OVA-24) protocol. Bronchial reactivity was assessed by using a ventilator (FlexiVent). OVA-treated animals had higher lung resistance and lung compliance compared to control groups (P<0.001). 8-Iso-PGF_2α levels in bronchoalveolar lavage (BAL) and 8-iso-PGF_2α immunoreactivity in lung tissue were analyzed. OVA-17 mice showed a 2.5-fold increased level of 8-iso-PGF_2α in BAL compared to PBS-17 mice (P=0.023). Lung tissue from OVA-24 mice had more intense 8-iso-PGF_2α staining compared to OVA-17 mice. This study showed an accumulation of F₂-isoprostanes in acute airway inflammation and a markedly increased tissue damage caused by oxidative stress in an ongoing inflammation.     

Plasma F2-isoprostane class VI isomers at 12–18 weeks of pregnancy are associated with later occurrence of preeclampsia

Preeclampsia (PE) has long been associated with early oxidative stress, although the symptoms occur later in pregnancy. We have hypothesized that the oxidative stress in PE, as characterized by the presence of F₂-isoprostane (F₂-isoP) isomers in late pregnancy, should already be present in plasma at the first regular visit of the obstetrical follow-up. There are 64 possible isomers of F₂-isoPs derived from the oxidation of arachidonic acid (AA), but only one of these isomers has been investigated so far in PE, the classical 8-iso-PGF_2α. Here, we have investigated two regioisomers of class III (8-iso-15(R)-PGF_2α and 8-iso-PGF_2α) and a mix of two isomers of class VI ((±)5-iPF_2α-VI) in plasma samples collected prospectively at 12–18 weeks from normotensive controls (n = 60) and pregnant mothers who developed PE later in pregnancy (n = 33). The plasma samples were subjected to alkaline hydrolysis followed by liquid–liquid extraction to extract total F₂-isoPs for later quantification by HPLC-MS/MS. The F₂-isoPs were normalized to either plasma volume or polyunsaturated fatty acid (PUFA) levels measured by GC-FID in plasma phospholipids. Early in pregnancy, only the class VI F₂-isoP isomers were found at concentrations significantly higher in women developing PE later in pregnancy (+13%; p = 0.0074). Normalization of F₂-isoPs to their substrate, AA, or the omega-3 to omega-6 ratio improved the predictability of PE as determined by receiver operating characteristic (from area under the curve of 0.67 to 0.68 and 0.70 respectively). Interestingly, omega-3 fatty acids were 25% higher in the control group than in the PE group (P = 0.0225). Omega-6 PUFAs correlated with F₂-Isop isomers only in cases of PE (r > 0.377; P >0.03, Spearman correlation). In sum, this study indicates that specific isomers of class VI are significant predictors of PE. This work also suggests that F₂-isoP isomers are not all generated and eliminated to the same extent and are influenced by the PUFA composition of plasma phospholipids.     

Isolation and measurement of urinary 8-iso-prostaglandin F2α by high-performance liquid chromatography and gas chromatography–mass spectrometry

8-iso-Prostaglandin F_2α (8-iso-PGF_2α) is a product of free radical-catalyzed peroxidation of arachidonic acid. Measurement of its urinary excretion has been proposed as an index of oxidative status in vivo. A stable isotope dilution method for its quantification by gas chromatography–electron capture chemical ionization mass spectrometry is described. Sample cleanup required the combined use of high-performance liquid chromatography and thin-layer chromatography. The inter-assay R.S.D. in two separate determinations was 1.6 (n=4) and 2.3% (n=4). The accuracy of the assay was evaluated through recovery experiments. The equation of the regression plot correlating the amounts added and recovered was y=0.91x−0.31, r=0.9916 (n=12). The pair of fragment ions ([M−181]⁻) at m/z 569 and m/z 573 was monitored for quantification. The mean 8-iso-PGF_2α excretion rate was 528±127 (S.D.) ng per day in five male volunteers and 730±305 ng per day in six females. Intake of 80 mg of lycopene per day by eleven volunteers for four weeks resulted in a non-significant reduction of 8-iso-PGF_2α excretion.     

The steady-state levels of oxidative DNA damage and of lipid peroxidation (F2-isoprostanes) are not correlated in healthy human subjects

Oxidative damage to DNA in human tissues can be determined by measuring multiple products of oxidative damage to the purine and pyrimidine bases using gas chromatography-mass spectrometry (GC-MS). Oxidative damage to lipids (lipid peroxidation) can be quantitated by the mass spectrometry-based determination of F₂-isoprostanes, specific end-products of the peroxidation of arachidonic acid residues in lipids. For both DNA base damage products and 8-epi prostaglandin F_2α (PGF_2α), there is a wide variation in levels between different healthy human subjects. We measured multiple products of oxidative damage to DNA bases in white cells, and 8-epi PGF_2α in plasma, from blood samples obtained from healthy human subjects in the UK and in Portugal. No correlation of 8-epi PGF_2α levels with levels of any modified DNA base (including 8-hydroxyguanine) was observed. We conclude that no single parameter can be measured as an index of “oxidative stress” or “oxidative damage” in vivo.     

Elevation of oxidative-damage biomarkers during aging in F2 hybrid mice: Protection by chronic oral intake of resveratrol

Resveratrol (RSV), a naturally occurring phytoalexin that can be found in red wine, berries, and peanuts, has been shown to extend both mean and maximum life span in model organisms. RSV has also been reported to shift the physiology of middle-aged mice on a high-calorie diet toward that of mice on a standard diet. These beneficial effects of RSV have been suggested to resemble caloric restriction. Our study in F2 four-way cross-hybrid mice was the first to evaluate the effects of aging and long-term RSV treatment (14.09 ± 3.4 mg/L in drinking water for 6 or 12 months) on biomarkers of oxidative damage to DNA, 8-hydroxy-2′-deoxyguanosine (8OHdG); lipid, 8-iso-prostaglandin_2α (8-iso-PGF_2α); and protein, protein carbonyl content (PCC). There was a significant age-dependent accumulation of oxidative damage to DNA, lipid, and protein as well as a clear increase in urine 8-iso-PGF_2α levels in the majority of mouse tissues. Rates of age-dependent increases in damage biomarkers varied between tissues. Chronic RSV treatment elevated total RSV plasma levels and reduced the observed age-dependent accumulation of (1) 8OHdG in liver and heart, (2) 8-iso-PGF_2α in heart and urine, and (3) PCC in liver and kidney. However, a 12-month RSV intake resulted in significant elevation of 8-iso-PGF_2α and PCC in kidney. Our studies demonstrate that RSV treatment consistently attenuated oxidative damage in tissues where age-related oxidative damage accumulation was prominent, but also suggested that chronic RSV treatment may induce nephrotoxicity.     

Lipid Peroxidation and Depressed Mood in Community-Dwelling Older Men and Women

It has been hypothesized that cellular damage caused by oxidative stress is associated with late-life depression but epidemiological evidence is limited. In the present study we evaluated the association between urinary 8-iso-prostaglandin F_2α (8-iso-PGF_2α), a biomarker of lipid peroxidation, and depressed mood in a large sample of community-dwelling older adults. Participants were selected from the Health, Aging and Body Composition study, a community-based longitudinal study of older persons (aged 70–79 years). The present analyses was based on a subsample of 1027 men and 948 women free of mobility disability. Urinary concentration of 8-iso-PGF_2α was measured by radioimmunoassay methods and adjusted for urinary creatinine. Depressed mood was defined as a score greater than 5 on the 15-item Geriatric Depression Scale and/or use of antidepressant medications. Depressed mood was present in 3.0% of men and 5.5% of women. Depressed men presented higher urinary concentrations of 8-iso-PGF_2α than non-depressed men even after adjustment for multiple sociodemographic, lifestyle and health factors (p = 0.03, Cohen’s d = 0.30). This association was not present in women (depressed status-by-sex interaction p = 0.04). Our study showed that oxidative damage may be linked to depression in older men from a large sample of the general population. Further studies are needed to explore whether the modulation of oxidative stress may break down the link between late-life depression and its deleterious health consequences.     

Nonylphenol exposure is associated with oxidative and nitrative stress in pregnant women

ABSTRACT

Animal studies have shown that exposure to nonylphenol (NP) increases oxidative/nitrative stress, but whether it does so in humans is unknown. This study examines prenatal exposure to NP and its effects on oxidatively/nitratively damaged DNA, lipid peroxidation, and the activities of antioxidants. A total of 146 urine and blood specimens were collected during gestational weeks 27–38 and hospital admission for delivery, respectively. Urinary NP was analyzed by high-performance liquid chromatography (HPLC). Urinary biomarkers of oxidatively/nitratively damaged DNA and lipid peroxidation, including 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodG), 8-nitroguanine (8-NO₂Gua), 8-iso-prostaglandin F_2α (8-isoPF_2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), were simultaneously analyzed using isotope-dilution liquid-chromatography/electron spray ionization tandem mass spectrometry. The activities of maternal plasma superoxide dismutase and glutathione peroxidase were analyzed by enzyme-linked immunosorbent assay. Urinary NP level was significantly associated with 8-oxodG and 8-NO₂Gua levels in late pregnancy, suggesting that NP may enhance oxidatively and nitratively damaged DNA. The adjusted odds ratios for high 8-oxodG level exhibited a significantly dose–response relationship with NP levels, stratified into four quartiles. 8-oxodG appears to be a more sensitive and effective biomarker of NP exposure than 8-NO₂Gua. These relationships suggest NP may play a role in the pregnancy complications.     

Content of liver and brain ubiquinol-9 and ubiquinol-10 after chronic ethanol intake in rats subjected to two levels of dietary α-tocopherol

To assess the effect of chronic ethanol ingestion in the content of the reduced forms of coenzymes Q₉ (ubiquinol-9) and Q₁₀ (ubiquinol-10) as a factor contributing to oxidative stress in liver and brain, male Wistar rats were fed ad libitum a basal diet containing either 10 or 2.5 mg α-tocopherol/100 g diet (controls), or the same basal diet plus a 32% ethanol-25% sucrose solution. After three months treatment, ethanol chronically-treated rats showed identical growth rates to the isocalorically pair-fed controls, irrespectively of α-tocopherol dietary level. Lowering dietary α-tocopherol led to a decreased content of this vitamin in the liver and brain of control rats, without changes in that of ubiquinol-9, and increased levels of hepatic ubiquinol-10 and total glutathione (tGSH), accompanied by a decrease in brain tGSH. At the two levels of dietary α-tocopherol, ethanol treatment significantly decreased the content of hepatic α-tocopherol and ubiquinols 9 and 10. This effect was significantly greater at 10 mg α-tocopherol/100 g diet than at 2.5, whereas those of tGSH were significantly elevated by 43% and 9%, respectively. Chronic ethanol intake did not alter the content of brain α-tocopherol and tGSH, whereas those of ubiquinol-9 were significantly lowered by 20% and 14% in rats subjected to 10 and 2.5 mg α-tocopherol/100 g diet, respectively. It is concluded that chronic ethanol intake at two levels of dietary α-tocopherol induces a depletion of hepatic α-tocopherol and ubiquinols 9 and 10, thus contributing to ethanol-induced oxidative stress in the liver tissue. This effect of ethanol is dependent upon the dietary level of α-tocopherol, involves a compensatory enhancement in hepatic tGSH availability, and is not observed in the brain tissue, probably due to its limited capacity for ethanol biotransformation and glutathione synthesis.     

Enhanced lipid peroxidation and inflammation during heat exposure in rats of different ages: Role of α-tocopherol

To investigate early events possibly related to the development of heat shock, we examined whether inflammatory-(interleukin-6, tumor necrosis factor α and 15-keto-13,14-dihydro-PGF_2α) and peroxidative-(8-iso-PGF_2α and malondialdehyde) markers are altered during acute heat exposure and aging. We also studied the relationships between inflammatory and peroxidative markers in these settings. In order to prevent these reactions developed as a consequence of the conditions mentioned above, we tested the effects of α-tocopherol. Our results demonstrated that 15-keto-13,14-dihydro-PGF_2α and malondialdehyde in the liver were altered during acute heat exposure in the young and middle-aged rats and could be predicted by changes in the levels of circulatory cytokines. Regardless of age, the supplementation with α-tocopherol prevented changes in the plasma cytokine levels and 15-keto-13,14-dihydro-PGF_2α and malondialdehyde levels in the liver, during acute heat exposure. This study notably emphasized the ability of α-tocopherol to prevent different heat induced mechanisms, involved in induction of inflammatory or peroxidative reactions.     

Quantitation of plasma total 15-series F2-isoprostanes by sequential solid phase and liquid-liquid extraction

F₂-isoprostanes are stereo- and regioisomers of prostaglandin F_2α (PGF_2α) and are used as biomarkers for lipid peroxidation. We modified our liquid-liquid extraction (LLE) procedure for F₂-isoprostane analysis (Anal. Biochem. 350 (2006) 41-51) to use a combination of solid phase extraction (SPE) and LLE to produce a cleaner extract that can be easily concentrated. In addition, shortening the high-performance liquid chromatography (HPLC) separation increased peak heights in HPLC-tandem mass spectrometry (HPLC-MS/MS) analysis. Both changes increased the overall sensitivity of the assay. MS/MS analysis served to confirm the identity of specific peaks that may be better biomarkers than the commonly measured 8-iso-PGF_2α.     

Increased levels of plasma 8-EPI-PGF2α in patients with end stage renal failure

Summary

F₂-isoprostanes are a series of prostaglandin-F₂ like compounds specifically derived from peroxidation of arachidonic acid by a mechanism independent of the cyclooxygenase pathway. Of these, 8-epi PGF_2α is shown to be a potent vasoconstrictor. In this study, we have analysed plasma 8-epi PGF_2α as a marker of oxidative stress in patients with end stage renal failure (ESRF) undergoing haemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). Plasma F₂-isoprostanes were isolated by solid-phase extraction on a C₁₈ followed by an NH₂ cartridge. Quantitative analysis of the F₂-isoprostanes as pentafluorobenzyl (PFB) ester/trimethylsilyl (TMS) ether derivatives was carried out by gas chromatography-electron capture mass spectrometry. For 34 individuals with ESRF, the mean level of esterified 8-epi PGF_2α was 0.58 ± 0.22 M; range 0.21–1.16 nM. 8-epi PGF_2α concentration in the patient groups was markedly higher (P<0.0005 by separate variance t-test) than that of control subjects (n=15) 0.28 ± 0.17 nM; range 0.02–0.63 nM. There was no difference in levels of 8-epi PGF_2α in plasma from patients undergoing HD or CAPD, nor was there any association with age, plasma lipids or plasma creatinine. These data provide direct evidence of increased oxidative stress in individuals with ESRF. This marker should be useful in clinical studies examining the degree of oxidative stress in vivo and the therapeutic impact of antioxidants.     

Increases in Tumor Necrosis Factor-α in Response to Thyroid Hormone-induced Liver Oxidative Stress in the Rat

Thyroid hormone-induced calorigenesis contributes to liver oxidative stress and promotes an increased respiratory burst activity in Kupffer cells, which could conceivably increase the expression of redox-sensitive genes, including those coding for cytokines. Our aim was to test the hypothesis that l -3,3',5-triiodothyronine (T₃)-induced liver oxidative stress would markedly increase the production of TNF- α by Kupffer cells and its release into the circulation. Sprague-Dawley rats received a single dose of 0.1 mg T₃/kg or vehicle (controls) and determinations of liver O₂ consumption, serum TNF-α, rectal temperature, and serum T₃ levels, were carried out at different times after treatment. Hepatic content of total reduced glutathione (GSH) and biliary glutathione disulfide (GSSG) efflux were measured as indices of oxidative stress. In some studies, prior to T₃ injection animals were administered either (i) the Kupffer cell inactivator gadolinium chloride (GdCl₃), (ii) the antioxidants α-tocopherol and N-acetyl-L-cysteine (NAC), or (iii) an antisense oligonucleotide against TNF-α (ASO TJU-2755). T₃ elicited an 80-fold increase in the serum levels of TNF-α at 22h after treatment, which coincided with the onset of thyroid calorigenesis. Pretreatment with GdCl₃ , α-tocopherol, NAC, and ASO TJU-2755 virtually abolished this effect and markedly reduced T₃-induced liver GSH depletion and the increases in biliary GSSG efflux. It is concluded that the hyperthyroid state in the rat increases the circulating levels of TNF-α by actions exerted at the Kupffer cell level and these are related to the oxidative stress status established in the liver by thyroid calorigenesis.     

Changes in α-tocopherol and retinol levels during cardiopulmonary bypass correlate with maximal arterial partial pressure of oxygen

Cardiopulmonary bypass (CPB) is associated with oxidative stress. This study examined antioxidant levels in adults undergoing CPB surgery and their correlation with clinical variables. Arterial blood samples were obtained from 27 patients undergoing CPB. The time-course variation of vitamin C (spectrofluorimetry), α-tocopherol and retinol (HPLC) levels were determined. Plasma vitamin C rose initially but gradually decayed during reperfusion until 60% reduction of baseline values post-surgery. α-Tocopherol and retinol were reduced along CPB with post-operative values ～25% lower than baseline. No significant changes were found for selenium and glutathione peroxidase. PaO₂ values rose steadily throughout CPB. A correlation existed for α-tocopherol and retinol depletion vs maximal PaO₂ throughout CPB but no correlation was found for antioxidant consumption vs duration of ischaemia and reperfusion and hypothermia level. In conclusion, consumption of arterial blood antioxidant vitamins occurs with CPB in relation with PaO₂ levels but not for other clinical variables measured in this study.     

Abnormally High Nourishment During Sensitive Periods Results in Body Weight Changes Across Generations

Objective : This study asked whether a brief period of over-nutrition during a developmentally sensitive time could impact the individual's adult weight and that of succeeding generations. Research Methods and Procedures : Female rat pups (F₁ generation) were randomly assigned to 1 of 3 groups: (1) a control group that was naturally reared by mothers; (2) another control group implanted with chronic gastric fistulas on postnatal day 4 and fed enough formula to match the growth of the mother-reared group; and (3) an experimental group gastrostomized and infused from day 8 through day 16 with a greater quantity of food than gastrostomy-reared controls (OF). On postnatal day 16, both gastrostomy-reared groups were returned to normal litters. Adult F₁ females from overfed and mother-reared groups were bred with normal males to yield an F₂ generation. F₂ adult females were bred to normal males to produce an F₃ generation. Results : When adult, the F₁ experimental group was heavier than control groups. F₂ adults from OF mothers were smaller than those from the control group. F₃ animals from OF grandmothers were heavier at weaning than F3 descendants from mother-reared animals. Discussion : Excess nourishment during a developmentally sensitive period changed the metabolic phenotype of one generation so dramatically that the gestational development and subsequent phenotype of two succeeding generations were also changed. The experiment models fetal effects of gestational diabetes in humans and may help to elucidate how, independent of genetic anomalies, secular changes can be detected across generations.     

Comparison of three oxidative stress biomarkers in a sample of healthy adults

Oxidative stress is a potentially important aetiological factor for many chronic diseases, including cardiovascular disease, neurodegenerative disease and cancer, yet studies often find inconsistent results. The associations between three of the most widely used biomarkers of oxidative stress, i.e. F₂-isoprostanes for lipid peroxidation and 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxo-dG) and the comet assay with FPG for oxidative DNA damage, were compared in a sample of 135 healthy African-American and white adults. Modest associations were observed between F₂-isoprostanes and the comet assay (r?=?0.22, p?=?0.01), but there were no significant correlations between 8-oxo-dG and the comet assay (r?=??0.09) or F₂-IsoP (r?=??0.04). These results are informative for researchers seeking to compare results pertaining to oxidative stress across studies and/or assessment methods in healthy disease-free populations. The development and use of oxidative stress biomarkers is a promising field; however, additional validation studies are necessary to establish accuracy and comparability across oxidative stress biomarkers.