P-糖蛋白在双壳贝类对镉累积和排出过程中的作用研究

Bivalves is a kind of high-quality protein resources, with high quality of meat. Harmful heavy metal Cd residues in bivalves exceeded easily when the breeding water was contaminated with Cd, because they are filter feeders, which brought potential safety hazard for food seriously. Cd was primarily binded with metallothionein of bivalves, which was diffcult to be excreted by itself. Currently, there are no effective methods to remove Cd from bivalves, inhibiting Cd from accumulating into bivalves would be a promising method. The inhibition of P-glycoprotein was intended to be clarified in the project. The P-glycoprotein was used to inhibit Cd in aquaculture water from accumulating into bivalves, while it was expressed and excreted by induced with rifampicin, the mechanism of P-glycoprotein in the inhibition process is defined. The content of P-glycoprotein and Cd in bivalves after stimulated by Cd and the variety of Cd content, ATPase activity, P-glycoprotein conformation after the activity of P-glycoprotein is inhibited and induced, are studied. The accumulation of Cd in bivalves was inhibited effectively by utilizing the transportation effect of P-glycoprotein, which made the residual determination of Cd reduced greatly. The definition of P-glycoprotein inhibition would resolve the problem of harmful heavy metal Cd accumulation in bivalves scientifically, which providing a novel and promising method for the residual determination of Cd in the culture of bivalves.

双壳贝类肉质鲜美，是一类优质的蛋白质资源。由于双壳贝类属于滤食性动物，养殖水域遭有害重金属Cd污染后，易导致贝类Cd残留超标，给食用带来了严重的安全隐患。Cd进入体内后主要与金属硫蛋白结合，难以自行排出体外。目前还没有有效的方法脱除双壳贝类体内的Cd，抑制Cd累积就成为一种新兴的方法。本课题拟明确P-糖蛋白的抑制作用。利用利福平诱导双壳贝类表达P-糖蛋白抑制水域中的Cd在体内累积，明确P-糖蛋白在抑制和排出过程中的作用机理。研究Cd应激后双壳贝类体内P-糖蛋白和Cd的含量、抑制和诱导P-糖蛋白活性后双壳贝类体内Cd的含量、ATP酶活性、P-糖蛋白构象的变化。该方法利用P-糖蛋白的转运作用，有效地抑制了Cd在双壳贝类体内累积，大大降低了双壳贝类的Cd残留量。明确P-糖蛋白的抑制作用，科学地解决了双壳贝类Cd的累积问题，可为双壳贝类养殖中Cd的残留问题提供新方法。

太平洋牡蛎肉质鲜美，是一类优质的蛋白质资源。但由于太平洋牡蛎属于滤食性动物，养殖水域遭到有害重金属镉污染后，易导致太平洋牡蛎镉残留超标，给食用带来了严重的安全隐患。本课题利用异搏定抑制P-糖蛋白的活性，明确了P-糖蛋白在太平洋牡蛎体内对镉的抑制作用。利用利福平诱导太平洋牡蛎表达P-糖蛋白抑制水域中的镉在体内累积，明确P-糖蛋白在抑制和排出过程中的作用。结果表明，1 μg/L异搏定处理组中太平洋牡蛎体内的镉含量增加了42.32%，1 μg/L利福平实验组和25 μg/L RFP实验组与1 μg/L染镉组相比，太平洋牡蛎体内的镉含量降低幅度分别达到了13.10%和31.89%。该方法利用P-糖蛋白的转运作用，有效地抑制了镉在太平洋牡蛎体内累积，大大降低了太平洋牡蛎的镉残留量。本课题在一定程度上解决了太平洋牡蛎镉的累积问题，为太平洋牡蛎养殖中镉的残留问题提供了新的方法。