两种有机磷农药对缢蛏(Sinonovacula constricta)鳃超微结构的影响

在实验室模拟缢蛏生长环境,研究结构、性质不同的两种典型有机磷农药(OPs)乐果和三唑磷对滩涂养殖生物缢蛏的毒性效应,通过电镜观察乐果和三唑磷对缢蛏鳃超微结构的影响.结果发现:乐果和三唑磷对缢蛏鳃超微结构的影响主要表现在对细胞核和各种细胞器(如线粒体、内质网、高尔基体)的伤害.主要病变为:细胞核变形,核膜凸起或凹陷,染色质发生凝聚或边缘化;线粒体肿大,双层膜溶解,内嵴部分消失;个别线粒体内嵴完全瓦解,形成电子透明区;粗面内质网水肿,核糖体部分脱落,片层结构间距增大;高尔基膜囊水肿,膜溶解,高尔基小泡破裂消失.本研究为了解不同OPs对缢蛏的毒性效应提供了病理形态学证据,为预测OPs对近海海洋生物及人类健康的影响提供有力的证据,为规范OPs的应用、制定海洋环境质量标准提供了部分基础理论依据.

Effects of dimethoate and triazophos on ultra-structural lesions in gill of Sinonovacula constricta

The toxic effects of two typical organophosphorous pesticides(OPs),dimethoate and triazophos,on Sinonovacula constricta(Lamarck) living in the intertidal sediment were investigated in this study.S.constricta was cultured in the simulate laboratory and the razor living surrounding.Samples were taken at 14d after exposed to OPs.The concentrations of OPs were determined with GC.The ultra-structure changes in gill epithelium of S.constricta were observed with an electron microscope.The ultra-structure in gill was destroyed when exposed to dimethoate and triazophos.The symptoms presented as lesions of nuclear,cellular organelles such as mitochondria,rough endoplasmic reticulum and Golgi apparatus.The nuclear became malformed.The nuclear envelopes were either convex or concave.The chromatin became agglomerated or on the edge.Mitochondria swelled up,and the cristae of mitochondria disintegrated partly,some disintegrated completely and became transparent electronic density area.The rough endoplasmic reticulum swelled up and ribosome fell from the rough endoplasmic reticulum.The lamina structure swelled and the space between them enlarged.The follicles of Golgi apparatus swelled,the membrane dissolved,and the vesicles disintegrated even disappeared.The results provided the pathologic and morphologic evidences for the toxic effects of OPs on S.constricta.The addition of histopathological lesions and OPs level in bivalve could be helpful to assess comprehensively the effects of OPs on S.constricta and the surrounding environment,furthermore to forecast the effects of OPs on the aquatic biota and human health.The study provided a partial theoretical support for establishing a criterion of OPs of the marine environment.