Oxidative Damage in Various Tissues of Rats Exposed to Radon

Abstract

Oxidative damage can be induced by many environmental stressors. 8-Hydroxydeoxyguanosine (8-OHdG) has been used as a biomarker of oxidative DNA damage in both in vitro and in vivo studies. In the present study, Wistar rats were exposed to radon gas at a concentration of 100,000Bq/m(3) for 12 h/d for 30, 60, and 120 d, equivalent to cumulative doses of 60, 120, and 240 working level months (WLM), respectively. Changes in levels of 8-OHdG, reactive oxygen species (ROS), and total antioxidant (T-AOC), as well as expressions of some DNA repair enzymes such as 8-oxoguanine DNA glycosylase (OGG1) and MutT homolog 1 (oxidized purine nucleoside triphosphatase, MTH1), were determined in rat urine, peripheral blood lymphocytes, and lung after exposure to radon. The results revealed an increase in 8-OHdG and ROS levels, a decrease in T-AOC levels, and reduced OGG1 and MTH1 expression levels. The elevated amount of 8-OHdG in urine or lymphocytes was positively correlated with the cumulative exposure dose, whereas OGG1 and MHT1 expression levels in lung were inversely correlated with cumulative exposure dose. These findings indicate that oxidative damage induced by radon may be involved in radon-induced carcinogenesis.

Estimation of tissue and crevicular fluid oxidative stress marker in premenopausal, perimenopausal and postmenopausal women with chronic periodontitis

“…The decline is also known to decrease sensitivity of oral tissues to the antioxidant effects of oestrogen further compounding the ROS‐mediated damage in periodontal tissues . However, the lack of significant correlation between the periodontal parameters and 8‐OHdG values in tissue and GCF may indicate dominance of oxidative damage in the periodontium caused by menopause than by periodontitis . It should also be taken into account that increase in 8‐OHdG concentration may not only reflect an increased burden of ROS, but also an impairment of the repair mechanisms .…”

“…61 However, the lack of significant correlation between the periodontal parameters and 8-OHdG values in tissue and GCF may indicate dominance of oxidative damage in the periodontium caused by menopause than by periodontitis. 63,64,66,67,70 It should also be taken into account that increase in 8-OHdG concentration may not only reflect an increased burden of ROS, but also an impairment of the repair mechanisms. 71,72 Whether menopause can induce or exacerbate existing periodontitis through ROS overload or due to impaired reparative mechanism is subject to debate and needs to be investigated further.…”

Nonlinear dose–response relationship between radon exposure and the risk of lung cancer

“…One of the postulated mechanisms of carcinogenesis is DNA damage by α-particles mediated by the production of reactive oxygen species that are produced in the cytoplasm and subsequently reach the nucleus (Nie et al, 2012;Sethi et al, 2012). α-Particles could induce DNA damage through double-strand breaks, leading to somatic mutations, chromosome aberrations, and finally, a deregulation of the cell cycle and subsequent carcinogenesis (Li and Tong, 2007;Robertson et al, 2013).…”

Potential Application of Benzo(a)Pyrene-Associated Adducts (Globin or Lipid) as Blood Biomarkers for Target Organ Exposure and Human Risk Assessment

“…Further, these biomarkers may be used not only for quantitative analysis of human exposure and risk assessment, but also to perform qualitative risk assessments that may predict the progress of chemical carcinogenesis as well as target organ toxicity (Jiang et al, 2013;Nie et al, 2012).…”