盐酸四环素对秀丽线虫(C.elegans)的急性与多代毒性研究

环境中抗生素的生态安全性受到越来越多的关注.以盐酸四环素(TCH)为对象、秀丽线虫(C.elegans)为模式生物,开展了急性与多代毒性研究.急性毒性实验表明盐酸四环素对秀丽线虫的LC50为167.5mg·L-(112h)、82.9mg·L-(124h),与现有四环素毒性数据相比,秀丽线虫对TCH的毒性更为敏感.分别对虫卵和成虫进行多代毒性的研究表明,盐酸四环素环境水平(μg·L-1)下的暴露,对秀丽线虫母代(P0)、子一代(F1)和子二代(F2)的逆向运动抑制率(RMI)、身体弯曲频率(BBFI)、Omega运动抑制率(OMI)3个行为学指标均具有显著的抑制作用,而且行为学指标比死亡率更加敏感,虫卵比成虫更加敏感.多代毒性作用的结果表明,盐酸四环素对P0、F1和F2产生的毒性存在差异,对于RMI和BBFI,其毒性作用强度为P0>F2>F1;对于OMI,其毒性作用强度为P0>F1≈F2.代际之间没有显示世代毒性逐代恶化或逐代修复的一般规律,可能与行为学指标的敏感性差异、盐酸四环素自身的降解、生物抗性有关.

Tetracycline Hydrochloride's Acute Toxicity and Behavioral Toxicity with Multiexposures at Environmental Levels on C. elegans

Antibiotics are a new threat to the ecological stability.Caenorhabditis elegans were used to study the acute toxicity and multigeneration toxicity of tetracycline hydrochloride(TCH).with reverse movement,body bending frequency and Omega movement as behavioral indicators.The LC50 values of TCH for C.elegans were 167.5mg·L-1(12h)and 82.9mg·L-1(24h).C.elegans showed more sensitive than previous acute toxicity studies on tetracycline.At environmental levels,TCH caused obvious behavioral defects with eggs having more susceptibility than adults,and all three behavioral indicators had more sensitivities than lethality as used in the acute toxicity.Toxic effects for three exposed generations showed the second exposed generation suffering the most severe defects,instead of typical pattern for toxicity between generations which contains successive deterioration or recovery.The primary reasons are quite related to the different sensitivities among different behavioral indicators,the degradation of TCH and the potential resistance resulted in C.elegans.