Farmers are frequently exposed to ultraviolet（UV） radiation which causes various diseases by inducing oxidative stress.This study aimed to assess the effects of sunblock on oxidative stress in the body.Eighty-seven ...Farmers are frequently exposed to ultraviolet（UV） radiation which causes various diseases by inducing oxidative stress.This study aimed to assess the effects of sunblock on oxidative stress in the body.Eighty-seven farmers were divided into two groups：those who wore sunblock for five days and those who did not.The total antioxidant capacity（TAC） in urine,which is an antioxidant indicator,and 8-hydroxy-2-deoxyguanosine（8-OHdG） levels in urine,an oxidative stress indicator,were measured.The urinary TAC of sunblock users was significantly higher than that of non-users,but urinary 8-OHdG levels were not significantly different.Even after adjustment for potential confounders,urinary TAC was found to be markedly increased with sunblock usage.These results suggest that sunblock is effective in preventing oxidative stress among farmers.In addition,they show that urinary TAC can be used as a good effect marker of oxidative stress caused by UV exposure.展开更多
A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that h...A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that help to limit damage from reactive oxygen species and chaperones that help to minimize protein misfolding or unfolding under stress conditions. To understand the molecular mechanisms that act to protect cells during primate torpor, the present study characterizes antioxidant and heat shock protein（HSP） responses in various organs of control（aroused）and torpid gray mouse lemurs, Microcebus murinus. Protein expression of HSP70 and HSP90 a was elevated to 1.26 and 1.49 fold, respectively, in brown adipose tissue during torpor as compared with control animals, whereas HSP60 in liver of torpid animals was 1.15 fold of that in control（P 〈 0.05）. Among antioxidant enzymes, protein levels of thioredoxin 1 were elevated to 2.19 fold in white adipose tissue during torpor, whereas Cu–Zn superoxide dismutase 1 levels rose to 1.1 fold in skeletal muscle（P 〈 0.05）. Additionally, total antioxidant capacity was increased to 1.6 fold in liver during torpor（P 〈 0.05）, while remaining unchanged in the five other tissues. Overall, our data suggest that antioxidant and HSP responses are modified in a tissue-specific manner during daily torpor in gray mouse lemurs. Furthermore, our data also show that cytoprotective strategies employed during primate torpor are distinct from the strategies in rodent hibernation as reported in previous studies.展开更多
基金supported by Ministry of Agriculture,Food and Rural Affairs,Republic of Korea
文摘Farmers are frequently exposed to ultraviolet（UV） radiation which causes various diseases by inducing oxidative stress.This study aimed to assess the effects of sunblock on oxidative stress in the body.Eighty-seven farmers were divided into two groups：those who wore sunblock for five days and those who did not.The total antioxidant capacity（TAC） in urine,which is an antioxidant indicator,and 8-hydroxy-2-deoxyguanosine（8-OHdG） levels in urine,an oxidative stress indicator,were measured.The urinary TAC of sunblock users was significantly higher than that of non-users,but urinary 8-OHdG levels were not significantly different.Even after adjustment for potential confounders,urinary TAC was found to be markedly increased with sunblock usage.These results suggest that sunblock is effective in preventing oxidative stress among farmers.In addition,they show that urinary TAC can be used as a good effect marker of oxidative stress caused by UV exposure.
基金supported by a Discovery grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada (Grant No. 6793)a grant from the Heart and Stroke Foundation of Canada (Grant No. G-140005874) to KBS. KBS holds the Canada Research Chair in Molecular PhysiologyCWW, KKB, and SNT all held NSERC postgraduate scholarships
文摘A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that help to limit damage from reactive oxygen species and chaperones that help to minimize protein misfolding or unfolding under stress conditions. To understand the molecular mechanisms that act to protect cells during primate torpor, the present study characterizes antioxidant and heat shock protein（HSP） responses in various organs of control（aroused）and torpid gray mouse lemurs, Microcebus murinus. Protein expression of HSP70 and HSP90 a was elevated to 1.26 and 1.49 fold, respectively, in brown adipose tissue during torpor as compared with control animals, whereas HSP60 in liver of torpid animals was 1.15 fold of that in control（P 〈 0.05）. Among antioxidant enzymes, protein levels of thioredoxin 1 were elevated to 2.19 fold in white adipose tissue during torpor, whereas Cu–Zn superoxide dismutase 1 levels rose to 1.1 fold in skeletal muscle（P 〈 0.05）. Additionally, total antioxidant capacity was increased to 1.6 fold in liver during torpor（P 〈 0.05）, while remaining unchanged in the five other tissues. Overall, our data suggest that antioxidant and HSP responses are modified in a tissue-specific manner during daily torpor in gray mouse lemurs. Furthermore, our data also show that cytoprotective strategies employed during primate torpor are distinct from the strategies in rodent hibernation as reported in previous studies.
