The first report demonstrating that prolonged endurance exercise promotes oxidative stress in humans was published more than 4 decades ago.Since this discovery,many ensuing investigations have corroborated the fact th...The first report demonstrating that prolonged endurance exercise promotes oxidative stress in humans was published more than 4 decades ago.Since this discovery,many ensuing investigations have corroborated the fact that muscular exercise increases the production of reactive oxygen species(ROS)and results in oxidative stress in numerous tissues including blood and skeletal muscles.Although several tissues may contribute to exercise-induced ROS production,it is predicted that muscular contractions stimulate ROS production in active muscle fibers and that skeletal muscle is a primary source of ROS production during exercise.This contraction-induced ROS generation is associated with(1)oxidant damage in several tissues(e.g.,increased protein oxidation and lipid peroxidation),(2)accelerated muscle fatigue,and(3)activation of biochemical signaling pathways that contribute to exercise-induced adaptation in the contracting muscle fibers.While our understanding of exercise and oxidative stress has advanced rapidly during the last decades,questions remain about whether exercise-induced increases in ROS production are beneficial or harmful to health.This review addresses this issue by discussing the site(s)of oxidant production during exercise and detailing the health consequences of exercise-induced ROS production.展开更多
Cell growth of Nitzschia closterium and Platymonas subcordiformis was stimulated under 4 and 8μg·L -1 anthrancene stress, respectively. The cell growth of two species was also stimulated under 30mg·L -1 str...Cell growth of Nitzschia closterium and Platymonas subcordiformis was stimulated under 4 and 8μg·L -1 anthrancene stress, respectively. The cell growth of two species was also stimulated under 30mg·L -1 streptomycin stress. The hormesis of marine microalgae cells under low level of anthrancene and streptomycin resulted in low level of free radical and decrease of microorganisms. Furthermore, the hormesis of marine microalgae was also discussed in this paper.展开更多
Combined chemical analyses and biological measurements were utilized to investigate potential toxicological effects and possible mechanisms involved in risk assessment of rare earth elements （REEs） on Viciafaba L. s...Combined chemical analyses and biological measurements were utilized to investigate potential toxicological effects and possible mechanisms involved in risk assessment of rare earth elements （REEs） on Viciafaba L. seedlings, which were hydroponically cultivated and exposed to various concentrations of lanthanum （La） for 15 days. The results showed that La contents in both the solution and roots increased with the increase of extraneous La, contributing to hormetic dose responses of superoxide dismutase （SOD）, catalase （CAT）, guaiacol peroxidase （GPX）, ascorbate peroxidase （APX） and endoprotease （EP） isozymes activities, and HSP 70 production enhanced at low doses but suppressed at higher doses of La. These physiological responses constituted antioxidant and detoxification systems against La-induced oxidative stress. The elevated La levels also contributed to oxidatively modified proteins, which were most responsible for subsequent cell death and growth retardation of the roots. By combination of hormetic and traditional threshold dose levels, the threshold dose range was deduced to be 108-195 μg La/g dry weight in the roots, corresponding to 0.90-3.12 mg/L of soluble La in the culture solution. It suggests that persistent applications of REEs may lead to potential ecological risk in the environment.展开更多
Root/shoot(R/S)ratio is an important index for assessing plant health,and has received increased attention in the last decades as a sensitive indicator of plant stress induced by chemical or physical agents.The R/S ra...Root/shoot(R/S)ratio is an important index for assessing plant health,and has received increased attention in the last decades as a sensitive indicator of plant stress induced by chemical or physical agents.The R/S ratio has been discussed in the context of ecological theory and its potential importance in ecological succession,where species follow different strategies for above-ground growth for light or below-ground competition for water and nutrients.We present evidence showing the R/S ratio follows a biphasic dose–response relationship under stress,typical of hormesis.The R/S ratio in response to stress has been widely compared among species and ecological succession classes.It is constrained by a variety of factors such as ontogeny.Furthermore,the current literature lacks dose-response studies incorporating the full dose–response continuum,hence limiting scientific understanding and possible valuable application.The data presented provide an important perspective for new-generation studies that can advance current ecological understanding and improve carbon storage estimates by R/S ratio considerations.Hormetic response of the R/S ratio can have an important role in forestry for producing seedlings with desired characteristics to achieve maximum health/productivity and resilience under plantation conditions.展开更多
文摘The first report demonstrating that prolonged endurance exercise promotes oxidative stress in humans was published more than 4 decades ago.Since this discovery,many ensuing investigations have corroborated the fact that muscular exercise increases the production of reactive oxygen species(ROS)and results in oxidative stress in numerous tissues including blood and skeletal muscles.Although several tissues may contribute to exercise-induced ROS production,it is predicted that muscular contractions stimulate ROS production in active muscle fibers and that skeletal muscle is a primary source of ROS production during exercise.This contraction-induced ROS generation is associated with(1)oxidant damage in several tissues(e.g.,increased protein oxidation and lipid peroxidation),(2)accelerated muscle fatigue,and(3)activation of biochemical signaling pathways that contribute to exercise-induced adaptation in the contracting muscle fibers.While our understanding of exercise and oxidative stress has advanced rapidly during the last decades,questions remain about whether exercise-induced increases in ROS production are beneficial or harmful to health.This review addresses this issue by discussing the site(s)of oxidant production during exercise and detailing the health consequences of exercise-induced ROS production.
文摘Cell growth of Nitzschia closterium and Platymonas subcordiformis was stimulated under 4 and 8μg·L -1 anthrancene stress, respectively. The cell growth of two species was also stimulated under 30mg·L -1 streptomycin stress. The hormesis of marine microalgae cells under low level of anthrancene and streptomycin resulted in low level of free radical and decrease of microorganisms. Furthermore, the hormesis of marine microalgae was also discussed in this paper.
基金supported by the National Natural Science Foundation of China (No. 20877032)the Foundation of State Key Laboratory of Pollution Control and Resources Reuse of China (No. PCRRF08011)
文摘Combined chemical analyses and biological measurements were utilized to investigate potential toxicological effects and possible mechanisms involved in risk assessment of rare earth elements （REEs） on Viciafaba L. seedlings, which were hydroponically cultivated and exposed to various concentrations of lanthanum （La） for 15 days. The results showed that La contents in both the solution and roots increased with the increase of extraneous La, contributing to hormetic dose responses of superoxide dismutase （SOD）, catalase （CAT）, guaiacol peroxidase （GPX）, ascorbate peroxidase （APX） and endoprotease （EP） isozymes activities, and HSP 70 production enhanced at low doses but suppressed at higher doses of La. These physiological responses constituted antioxidant and detoxification systems against La-induced oxidative stress. The elevated La levels also contributed to oxidatively modified proteins, which were most responsible for subsequent cell death and growth retardation of the roots. By combination of hormetic and traditional threshold dose levels, the threshold dose range was deduced to be 108-195 μg La/g dry weight in the roots, corresponding to 0.90-3.12 mg/L of soluble La in the culture solution. It suggests that persistent applications of REEs may lead to potential ecological risk in the environment.
基金supported by JSPS KAKENHI Grant Number JP17F17102German Research Foundation(BE4189/1-3)+1 种基金the US Air Force [AFOSR FA9550-13-1-0047]Exxon Mobil Foundation [S18200000000256]
文摘Root/shoot(R/S)ratio is an important index for assessing plant health,and has received increased attention in the last decades as a sensitive indicator of plant stress induced by chemical or physical agents.The R/S ratio has been discussed in the context of ecological theory and its potential importance in ecological succession,where species follow different strategies for above-ground growth for light or below-ground competition for water and nutrients.We present evidence showing the R/S ratio follows a biphasic dose–response relationship under stress,typical of hormesis.The R/S ratio in response to stress has been widely compared among species and ecological succession classes.It is constrained by a variety of factors such as ontogeny.Furthermore,the current literature lacks dose-response studies incorporating the full dose–response continuum,hence limiting scientific understanding and possible valuable application.The data presented provide an important perspective for new-generation studies that can advance current ecological understanding and improve carbon storage estimates by R/S ratio considerations.Hormetic response of the R/S ratio can have an important role in forestry for producing seedlings with desired characteristics to achieve maximum health/productivity and resilience under plantation conditions.
