镉暴露对文蛤雄性生殖细胞的影响

以文蛤(Meretrix meretrix)为实验材料,采用体外暴露法进行镉染毒,镉离子浓度设置为0、1.5、3、6和12 mg·L-1.染毒5天后解剖取材,测量其精子浓度、运动能力、顶体酶活性和核DNA完整性；目的是从生理、生化和分子生物学角度综合评价镉对文蛤雄性生殖细胞的影响.实验结果表明,文蛤精子浓度、运动能力、顶体酶、DNA完整性均在镉浓度小于成体半致死浓度的情况下,与镉浓度呈现出显著的剂量-效应关系.对镉离子的敏感性分别为:DNA完整性＞精子浓度＞顶体酶活性＞快速运动比例＞运动比例.文蛤雄性生殖细胞的生理、生化指标均可作为重金属镉污染海洋贝类毒性效应的指示物.

Effects of cadmium exposure on spermatozoon of Meretrix meretrix

To investigate the toxicological effects of cadmium on the spermatozoon of Meretrix meretrix at physiological, biochemical and molecular biological level, animals were exposed to Cd²⁺ solution at different concentrations (0, 1.5 mg·L^-1, 3 mg·L^-1, 6 mg·L^-1 and 12 mg·L^-1). After five days, the density, movement, acrosin activity as well as DNA integrity of the sperm were measured. The results showed that there was an obvious dose-response relationship between cadmium concentration and the density, movement, acrosin activity, and DNA integrity of the sperm when the cadmium concentration is under LC₅₀. The sensitivity of the above indexes to cadmium is DNA integrity > sperm's concentration > acrosin activity > the proportion of rapid movement > the proportion of movement. The physiological and biochemical indexes of spermatozoon of M. meretrix could be considered as potential biomarkers for detecting the deleterious effects of the heavy metals in marine molluscs.