摘要
Hormesis效应因其表现出的低浓度促进和高浓度抑制的特殊现象逐渐成为毒理学研究的热点.近年来,人们对抗生素的Hormesis效应进行了大量的研究.吲哚作为一种广泛存在的信号分子,对细菌的多种生理活动都起着重要的调控作用,吲哚是否可能参与调控抗生素对细菌的Hormesis效应是值得我们关注的问题.本文以磺胺甲氧哒嗪(Sulfamethoxypyridazine,SMP)为研究对象,以大肠杆菌为模式生物,建立了大肠杆菌产吲哚浓度的测定方法,并利用该方法测定了SMP对大肠杆菌的Hormesis效应下,大肠杆菌产吲哚的浓度随SMP浓度增加的变化情况.结果显示,当SMP对大肠杆菌的生长起促进作用时,细菌单位OD600产吲哚的浓度随SMP浓度的增加呈现了下降的趋势;当SMP对大肠杆菌的生长表现为抑制作用时,细菌单位OD600产吲哚的浓度随SMP浓度的增加呈现了逐渐上升的趋势.通过初步探究我们推测,SMP可能通过诱导大肠杆菌产生吲哚,并以吲哚作为信号分子调控大肠杆菌的分裂,从而对大肠杆菌的生长表现出Hormesis效应.本研究为尚未有定论的Hormesis机制提供了一定的理论指导.
Hormetic effect characterized by stimulation at low concentrations and inhibition at high concentrations has increasingly become the focus of toxicological research.In recent years,the hormetic effect of antibiotics has been investigated extensively.Indole,an important intercellular signaling molecule,plays a crucial role in the regulation of bacterial physiological activities.Whether indole can regulate the hormetic effect of antibiotic on bacteria is worthy of our attention.In this study,the indole production of Escherichia coli(E.coli)under the effect of sulfamethoxypyridazine(SMP)was determined by the method we established.The results showed that,the concentration of indole produced by per optical density(OD600)of E.coli decreased gradually when SMP exhibited stimulatory effect on the growth of bacteria.However,when the bacterial growth was inhibited by SMP,the concentration of indole produced by per OD600 of E.coli increased considerably.Through analysis,we speculate that SMP may induce E.coli to produce indole and then use indole as a signaling molecule to regulate the bacterial division,thus causing the hormetic effect on the bacterial growth.This study provides a new possibility for the unknown mechanism of hormesis.
作者
潘永正
孙昊宇
王雅娟
张跃恒
印春生
林志芬
PAN Yongzheng;SUN Haoyu;WANG Yajuan;ZHANG Yueheng;YIN Chunsheng;LIN Zhifen(College of Marine Ecology and Environment,Shanghai Ocean University,Shanghai,201306,China;State Key Laboratory of Pollution Control and Resource Reuse,College of Environmental Science and Engineering,Tongji University,Shanghai,200092,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第4期950-959,共10页
Environmental Chemistry
基金
同济大学污染控制与资源化研究国家重点实验室自主研究(重点)项目(PCRRK16007)
国家自然科学基金(21377096,21577105)
上海市科学技术委员会(14DZ2261100)
国家水污染防治科技重大项目(2018ZX07109-1)
环境化学与生态毒理学国家重点实验室(KF2016-11)资助