三丁基锡对褐菖鲉胚胎卵黄囊吸收的影响

鱼类胚胎期的营养对各种器官的发育至关重要,环境条件对营养吸收的影响会增加畸形率和死亡率。研究三丁基锡(tributyltin,TBT)对鱼类胚胎期营养吸收的影响有助于深入认识TBT对鱼类胚胎发育的毒性。本实验以海洋经济鱼类褐菖鲉(Sebastiscus marmoratus)为对象,研究环境水平TBT(0.01、0.1、1、10 ng.L-1)对胚胎卵黄囊吸收的影响。通过油红O染色,发现TBT暴露引起褐菖鲉胚胎血管系统中脂类染色信号减少,而卵黄中的脂类染色正常,说明TBT可能影响了胚胎正常血液循环,从而影响了正常的营养运输。另外,TBT对Na+,K+-ATP酶、碱性磷酸酶活性的抑制以及对甲状腺激素受体α和糖皮质激素受体基因表达的影响可能和其对卵黄囊的吸收抑制有关。TBT对鱼类胚胎卵黄吸收的抑制将影响鱼类的生长和发育,增加畸形率和死亡率,最终导致鱼类种群数量减少。

Effects of tributyltin on the absorption of yolk sac in Sebastiscus marmoratus embryos

Organotin compounds,especially tributyltin(TBT),are widely used as biocidal additives in antifouling paints and have become a ubiquitous marine environmental contaminant.Some current studies addressing the embryonic toxicity of TBT on fishes have been reported.The deformities were mainly shown as unusual bone growth and muscle disorders.Nutrition was important for the development of various organs.It could provide deep insight into the embryonic toxicity of TBT on fishes to better understand the effects of TBT on the absorption of yolk sac.The present study was conducted to investigate the effects of TBT at environmentally relevant concentrations(0.01,0.1,1,10 ng·L-1) on the absorption of yolk sac in rockfish(Sebastiscus marmoratus) embryos.Oil red O staining assay showed a weakened lipid signal in vascular system(dorsal aorta and posterior cardinal vein) and head,especially around capsule ears,in embryos exposed to TBT,but no change of lipid signal was found in the yolk sac,which suggested that TBT may affect the normal blood circulation,thus affecting the normal nutrition transport.In addition,TBT inhibited Na+,K+-ATP enzyme activity,which could affect normal cardiac function and blood circulation,and ultimately depress the absorption of yolk sac.Alkaline phosphatase,thyroid hormone receptor and the glucocorticoid receptor were closely related to the growth and metabolism in fish.The suppression of alkaline phosphatase and the changes of thyroid hormone receptor and glucocorticoid receptor expression could affect the absorption and metabolism of the yolk sac,and adaptability to the environment.The results provided new information of embryonic toxicity of TBT,which was important for fully understanding the environmental endocrine disrupting effects and mechanism of TBT.Depending on the effects of TBT on absorption of yolk sac in embryos,TBT exposure might influence the growth and development,increase the deformity rate and mortality and lead to the decline of fish resources.As an important part of the food chain in water environment,fish has an important influence on the ecological system.The results provide important evidences for constituting marine environment policies and evaluating effects of organotin compounds on resources of marine fish.