镉对中华绒螯蟹鳃组织及其亚显微结构的影响

EFFECTS OF CADMIUM ON TISSUE AND ULTRASTRUCTURE OF GILL OF ERIOC HEIR SIN EN SIS (M. EDW.)

于1986年10月—1987年5月以不同浓度的镉(6.25,12.5和25.0mg/L),对采自长江口的中华绒螯蟹进行了急性毒性试验,以光镜和电镜观察。结果表明,受镉作用后,整个鳃叶增厚,血腔增大;血细胞增多,上皮层破坏直至解体;鳃上皮细胞的亚显微结构因镉的作用顶膜微绒毛和底膜内折消失,线粒体膨胀直至解体。以统计分析检验了对照组和不同镉浓度组处理的蟹鳃之间的形态指标的差异,并分析了这些形态指标的变化同镉浓度的相关性。通过对鳃上皮细胞与鳃生理功能关系的分析,认为镉对鳃组织及细胞结构的损害影响了鳃组织的能量代谢、离子主动转运机制及渗透压调节能力。

Acute poisoning experiments on Eriocheir sinensis (M. Edw.) from the estuary of the Changjiang River were made at varying concentrations of cadmium (6.25, 12.5 and 25.0 mg/L) by means of light and electron microscope from October, 1986 to May, 1987.The results showed that entire gill lamella was irregularly thickened, and haemolymph spaces in which there were increased haemocytes were enlarged as a result of effects of lower concentrations of cadmium on the gill. With exposure to higher concentrations of cadmium the integrality of the gill epithelial layers and the gill epithelial cells were damaged, culminating in their breakdown.The ultrastructural changes of cadmium effects on the gill epithelial cells include enlarged sub-cuticular spaces and intracellular vacuoles, disappearance of apical microvilli and basal infoldings, decrease of numbers of cell organelle such as mitochondrion, swollen and disintegrated mitochondria and diffusion of cytoplasm and chromatin. The gill epithelial cells were disintegrated with exposure to the highest concentration of cadmium.Differences of morphometric indicators between untreated and treated specimens with the concentrations of cadmium were tested, and correlativity of the change of the morphometric indicators with the concentrations of cadmium was also calculated by using of statistical analysis.It is assumed that the damage of the integrality of the gill epithelial layers, the structure of apical microvilli-mitochondrion and basal in folding-mitochondrion of epithelial cell and abundant mitochondria induced by cadmium affects energy metabolism of the gill tissue arid mechanism of active ion transport and function of osmoregulation after analysis of relationship between the gill epithelial cells and physiological function of the gill.