铅在日本沼虾体内的分布和积累

应用组织化学、透射电镜和原子吸收光谱分析等方法，研究了Pb在日本沼虾各主要器官和组织中的分布和积累情况。结果表明，在浓度为0．625mg·L^-1Pb溶液暴露10d后的日本沼虾触角腺内，具有大量的电子密度较高的Pb颗粒．在电镜下细胞内的溶酶体中沉积有大量的Pb颗粒，这些Pb通过积聚，在细胞顶端部位逐渐增多，从而出现外排现象．中肠细胞内含有Pb颗粒，细胞质出现空泡化，核膜和线粒体内嵴部分解体．肝胰脏细胞内除分布有少量Pb颗粒外，细胞结构基本完整．在沼虾鳃细胞内未发现Pb颗粒，但在鳃丝之间发现少量Pb颗粒吸附在鳃丝的表面原子吸收光谱分析结果表明，触角腺中Pb含量最高，达637．6mg·kg^-1；触角腺在Pb的解毒方面起着重要作用。

Accumulation and distribution of lead in Macrobrachium nipponense

The accumulation and distribution of lead granules in the major organs of Macrobrachium nipponense were studied by means of histochemistry, transmission electron microscope (TEM) and atomic absorption spectrophotometer (AAS) analysis. The results showed that many high electronic dense lead granules (EDG) were found primarily in the antennal gland of this species exposed to 0.625 mg.L-1 Pb2+ for 10 days. Under TEM, lead granules were deposited in lysosome, then gradually accumulated in cell apex, and finally individually discharged into gland lumen by apocrine secretion and excreted with urine. There was a small quantity of lead granules in the cells of midgut. Many vacuolus were observed in the cytoplasm of the cells, and the nuclear membranes and cristae in mitochondria were disintegrated partially. The structure of hepatopancreas cells basically remained intact, although there were a few of lead granules in the cells. No lead granule was found in the cells of gills, but a few of lead granules adsorbed on the surface of gill filaments among the gill filaments. The highest concentration (637.6 mg.kg-1) of lead was found in antennal gland by AAS, suggesting that the antennal gland might play an important role in detoxifying process of lead.