3-nitrotyrosine and 8-oxo-7-8-dihydrodeoxyguanine

The purpose of this study was to use histological and biochemical methods in order to evaluate changes taking place in the ovarian of rats exposed to the effect of a 900-megahertz (MHz) electromagnetic field (EMF) in middle and late adolescence.. Twenty-four 34-d-old female Sprague-Dawley rats were assigned equally to control, sham and EMF groups. EMF group rats were exposed to the effect of a 900-MHz EMF for 1 h a day, at the same time every day between postnatal days 35 and 59, while inside an EMF cage. Sham group rats were kept inside the EMF cage for the same time between postnatal days 35 and 59 without being exposed to any EMF effect. At the end of the study, rats' ovarian were removed and blood specimens were taken. Right ovarium tissues were subjected to routine histological procedures and stained with hematoxylin and eosin, periodic acid shift and Masson's trichrome. Follicles were counted in ovarian sections stained with hematoxylin and eosin. The TUNEL method was used to evaluate apoptosis. Left ovarian tissue and blood specimens were investigated biochemically.. Histopathological examination of EMF group ovarian tissue revealed thinning in the zona granulosa and theca layers, shrinking in granulosa cells, reduced mitotic activity and leukocyte infiltration in the follicles and stroma. Secondary follicle numbers in the EMF group were significantly lower than in the other groups. In terms of biochemistry, EMF and sham group superoxide dismutase, catalase and anti-Mullerian hormone levels and EMF group 3-nitrotyrosine values increased significantly compared to the control group. EMF and sham group serum catalase and 8-hydroxy-deoxiguanosine values increased significantly compared to the control group, and EMF group total oxidant status and oxidative stress index values were significantly higher compared to the sham and control groups.. A total of 900-MHz EMF applied in middle and late adolescence may cause changes in the morphology and biochemistry of the rat ovarium.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Body Weight; Catalase; Electromagnetic Fields; Female; Granulosa Cells; Guanine; Humidity; Leukocytes; Mitosis; Organ Size; Ovary; Oxidative Stress; Rats; Rats, Sprague-Dawley; Temperature; Theca Cells; Time Factors; Tyrosine

Previous studies have suggested the importance of reactive oxygen species in all the steps of carcinogenesis. Antioxidant enzymes are considered as the most specific and efficient way to protect cells from reactive oxygen species. The purpose of the current study was to identify the role of oxidative stress and major antioxidant enzymes in ovarian carcinomas.. The material consisted of 68 invasive ovarian carcinomas which were studied by immunohistochemistry with antibodies to antioxidant enzymes peroxiredoxins (Prxs) I-VI and thioredoxin and oxidative stress markers nitrotyrosine and 8-hydroxydeoxyguanosine (8-OHdG). Both the intensity and the extent of the stainings were assessed, and the nuclear and cytoplasmic expressions were evaluated separately.. The study revealed the hydroxyl radical-derived oxidative stress marker in DNA, 8-OHdG, to be a powerful prognostic factor in ovarian carcinoma (Kaplan-Meier survival log-rank-analysis P = 0.003; risk of death to ovarian carcinoma 2.69; 95% confidence interval 1.35-5.35. 8-OHdG was also associated with poor differentiation (P = 0.053), higher stage (P < 0.001), and non-optimal surgical outcome (P = 0.002). High cytoplasmic Prx IV immunostaining was associated with a better prognosis (P = 0.024), and elevated cytoplasmic expression rates of Prxs V (P = 0.043) and VI (P = 0.032) were associated with a higher stage.. To conclude, it appears that hydroxyl radical-derived oxidative stress, but not nitric oxide radical-derived oxidative stress, plays a significant role in ovarian carcinogenesis. Immunohistochemical assessment of 8-OHdG could provide a useful prognostic marker in ovarian cancer.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Antioxidants; Biomarkers, Tumor; Carcinoma; Cell Nucleus; Cytoplasm; DNA Adducts; Female; Guanine; Humans; Immunohistochemistry; Neoplasm Staging; Ovarian Neoplasms; Oxidative Stress; Prognosis; Survival Analysis; Tyrosine

Cigarette smoking increases the risk of developing atherosclerosis and ischaemic heart disease. Smoking-induced oxidative stress is considered to favour oxidation of low-density lipoprotein (LDL) and subsequently promotes the atherogenic process. We investigated whether peroxynitrite, a reaction product of cigarette smoke, is involved in facilitated oxidation of LDL in smokers.. Plasma LDL was obtained from 10 healthy asymptomatic cigarette smokers and 10 healthy nonsmokers. The state of enhanced oxidative stress in the plasma was assessed by LDL subfraction assay using anion-exchange high-performance liquid chromatography (AE-HPLC) and measurements of thiobarbituric acid-reactive substances (TBARS), 8-hydroxydeoxyguanosine (8-OHdG), vitamin E, 3-nitrotyrosine and 3-chlorotyrosine.. Smokers showed a significantly higher level of TBARS and 8-OHdG as well as a significantly lower level of vitamin E than nonsmokers, even after stopping smoking for 10 h or more. The LDL subfraction assay demonstrated an increase in oxidatively modified LDL, as expressed by lower levels of LDL1 and higher levels of LDL2. The 3-nitrotyrosine levels in apolipoprotein B in LDL were significantly higher in smokers than nonsmokers, while the 3-chlorotyrosine levels remained unchanged. In addition, these changes observed in the smokers were further accelerated within 30 min after resumption of cigarette smoking when compared with the levels before smoking resumption.. The present study suggests that peroxynitrite plays a significant role in oxidative modification of plasma LDL induced by cigarette smoking.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Biomarkers; Chromatography, High Pressure Liquid; Female; Guanine; Humans; Lipoproteins, LDL; Male; Oxidation-Reduction; Oxidative Stress; Peroxynitrous Acid; Smoking; Thiobarbituric Acid Reactive Substances; Tyrosine; Vitamin E