Smoking induces oxidative stress inside the Graafian follicle

BACKGROUND: A growing body of evidence indicates that pro-oxidant/antioxidant balance inside ovarian follicles plays an important role in folliculogenesis. Over 20% of women of reproductive age in Europe and the USA regularly smoke cigarettes. The impact of tobacco smoking on the intrafollicular markers of oxidative stress has not been fully elucidated. The objective of the present study was to test the hypothesis that cigarette smoking affects the intrafollicular redox milieu. METHODS: In follicular fluid samples originating from 108 IVF patients, lipid peroxidation was assessed by the thiobarbituric reactive substances method and total antioxidative capacity was quantified by the luminol enhanced chemiluminescence method. The level of patients' exposure to the cigarette smoke was evaluated by measuring the follicular fluid cotinine concentration by means of radioimmunoassay. RESULTS: Intrafollicular exposure to cigarette smoke metabolites was associated with a significant increase in follicular lipid peroxidation intensity (P < 0.001), which was accompanied by a significant decrease in the local antioxidative potential (P = 0.004). CONCLUSION: The results indicate that active smoking affects the pro-oxidant/antioxidant balance inside the pre-ovulatory ovarian follicle by inducing intrafollicular oxidative stress. This provides another possible explanation for impaired folliculogenesis in female smokers.     

脂质过氧化对培养的人内皮细胞血管细胞粘附分子-1表达的影响

目的:观察脂质过氧化对培养的人内皮细胞血管细胞粘附分子-1表达的影响。方法:培养的人脐静脉内皮细胞随机分为实验组和对照组。实验组与不同浓度联胺(1μmol/L、5μmol/L、10μmol/L)作用8h, 对照组不加联胺。细胞原位杂交和细胞酶联免疫吸附法分别测定内皮细胞血管细胞粘附分子-1mRNA和蛋白表达。结果:细胞原位杂交结果图像分析表明, 实验组平均吸光度值分别为0.147±0.013、0.292±0.020和0.396±0.022, 是对照组(0.077±0.011)的1.91倍、3.79倍和5.14倍。方差分析表明, 各组间两两比较有显著差异(P<0.01)。细胞酶联免疫吸附测定结果, 实验组平均吸光度值分别是0.158±0.008、0.220±0.017和0.321±0.023, 为对照组(0.104±0.016)的1.53倍、2.12倍和3.09倍。各组间两两比较有显著差异(P＜0.01)。结论:人脐静脉内皮细胞脂质过氧化增加血管细胞粘附分子-1mRNA和蛋白表达, 这可能促进单核细胞粘附血管内皮, 在动脉粥样硬化发生发展中起重要作用。     

Lipid components in the detergent-resistant membrane microdomain (DRM) obtained from the synaptic plasma membrane of rat brain

Lateral association of sphingolipids and cholesterol is considered to form membrane microdomains such as “lipid rafts” obtainable as a detergent-resistant membrane microdomain (DRM) fraction after solubilization with a non-ionic detergent and density gradient centrifugation. Since not only sphinogolipids and cholesterol, but also functional lipids such as phosphatidylinositol 4,5-bisphosphate (PIP₂) are reported to be localized in DRM prepared from several cultured cells, this domain is considered to be a platform mediating lipid-signaling. Although PIP₂ is considered to have pivotal roles in the nervous system, little information is available on the localization of PIP₂ in the DRM within the synaptic plasma membrane (SPM) obtained from matured rat brains. In this study, in order to know the localization of PIP₂ in SPM-derived DRM, we measured the amount of PIP₂ in SPM and SPM-derived DRM, by the thin-layer chromatography blotting method, using a GST-fusion protein of the pleckstrin-homology domain of phospholipase Cδ1 as a PIP₂ binding probe. About 10% of the PIP₂ in SPM was recovered in DRM. In contrast, over 40% recovery was observed for the membrane cholesterol and sphingomyelin, and about 30% recovery was observed for phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine in the DRM were detected using the thin-layer chromatography method. Since the recovery of proteins in DRM was about 10%, the result indicates that there occurs no enrichment of PIP₂ in DRM prepared from SPM.     

Effects of fibrinogen on lipid peroxidation in patients with coronary heart disease and in vitro

In patients with coronary heart disease oxidizability of lipids during Cu²⁺-induced oxidation of blood plasma inversely correlated with fibrinogen content. A positive correlation was found between the amount of lipid peroxidation products in the plasma from these patients and fibrinogen content. The increase in fibrinogen content was associated with high levels of total lipids and triglycerides and low concentration of high-density lipoprotein cholesterol. In vitro experiments demonstrated that fibrinogen reduces oxidizability of blood plasma. Our results suggest that the decrease in lipid oxidizability at high concentration of fibrinogen in patients with coronary heart disease is related to predominant oxidation of fibrinogen and its competition with plasma lipids during Cu²⁺-induced oxidation.     

Relationship between oxidative stress and embryotoxicity of hydrosalpingeal fluid

BACKGROUND: Oxidative stress mechanisms are involved in the pathophysiology of many reproductive disorders. The objective of this study was to characterize oxidative stress parameters in hydrosalpingeal fluid (HSF) and examine their possible role in early embryo development. METHODS AND RESULTS: HSF was aspirated at laparoscopic salpingectomy in 11 infertile women. Reactive oxygen species (ROS), total (non-enzymatic) antioxidant capacity (TAC) and lipid peroxidation (LPO) were assayed. Two-cell mouse embryos were incubated with 25, 50 or 75% HSF and the blastocyst development rate was observed. ROS was detected in five of 11 (45%) HSF samples with a mean of 4.2 x 10(4) c.p.m. LPO was detected in all samples at a mean (+/- SD) value of 5575.4 +/- 6091.9 micromol/l malonaldehyde. The mean blastocyst development rate at 25, 5+/- 0 and 75% HSF and in the control group was 88.9 +/- 9.4, 65.7 +/- 19.1, 45.7 +/- 5.7 and 96.7% respectively (P < 0.0001). The blastocyst development rate was positively correlated to ROS concentrations (P < 0.02) but was not significantly related to LPO. CONCLUSIONS: The blastocyst development rate decreased with increasing concentrations of HSF. For the first time, the presence of ROS, LPO and TAC activity in human HSF was characterized. A possible role of oxidative stress in the embryotoxicity of HSF is suggested.     

Primary biliary cirrhosis and coronary atherosclerosis: Protective antioxidant effect of bilirubin

Increased concentration of lipid peroxidation products in patients with primary biliary cirrhosis is related to elevation of serum lipid content, but not to activation of lipid peroxidation. Hyperbilirubinemia in patients with primary biliary cirrhosis is accompanied by a decrease in the concentration of lipid peroxidation products and increase in antioxidant activity of blood serum. Antioxidants play a major role in the prevention of atherosclerosis. We hypothesized that the absence of increased risk of atherosclerosis in patients with primary biliary cirrhosis is due to inhibition of lipid peroxidation in blood serum by antioxidant compound bilirubin. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 1, pp. 23–28, January, 2008     

Effect of beta-amyloid peptide fragment 25-35 on nonselective permeability of mitochondria

Beta-Amyloid peptide fragment 25-35 potentiated phosphate- and calcium-induced opening of mitochondrial channels and caused swelling of mitochondria (even without exogenous calcium and phosphate). These changes were accompanied by accumulation of lipid peroxidation products in mitochondria. Specific inhibitors of mitochondrial channels ADP and cyclosporine A prevented beta-amyloid peptide-induced swelling of mitochondria. Our findings suggest that potentiation of mitochondrial channel opening is an important component of the neurodegenerative effect of beta-amyloid.     

Drug resistance in the fission yeast Schizosaccharomyces pombe: pleiotropic mutations affecting the oleic acid and sterol composition of cell membranes

Summary The whole cell lipid and sterol content of the drug resistant strains cyh1, cyh3 and cyh4 was compared with that of wild type by thin layer and gas liquid chromatography and by UV spectrophotometric analysis. The cyh3 and cyh4 strains had a decreased content of the unsaturated 18:1 fatty acid oleic acid, a decreased content of ergosterol and an increased content of 24,28 dehydroergosterol with respect to wild type. The cyh1 strain, however, only showed a decreased content of ergosterol and an increased content of 24,28 dehydro-ergosterol when compared to wild type.