氯化镉对不同倍性泥鳅鳍细胞系的毒性效应

旨在研究不同浓度氯化镉对60~80 代二倍体和三倍体泥鳅鳍细胞系（DIMF和TRMF）的毒性效应，比较不同倍性细胞系间的敏感性差异。采用MTT比色法测定半致死浓度，采用酶活力测定法、微核试验和实时定量PCR法测定了氯化镉对2 种细胞系的细胞毒性和遗传毒性。结果表明：氯化镉处理下DIMF、TRMF细胞系半致死浓度分别为(24.0±0.7)、(27.3±1.3) μmol/L。2 种细胞系的SOD、GSH-Px活性随着氯化镉浓度的增加，呈现先升高后降低的趋势，而GST活性则表现为逐渐降低。随着氯化镉浓度的增加微核率先升高后降低，DIMF、TRMF最大微核率分别为(7.33±0.33)‰、(8.33±0.67)‰。经氯化镉处理的细胞金属硫蛋白(MT)表达量显著增加，30 μmol/L 浓度组表达量最大，分别为对照组的55.6 和57.6 倍。研究表明，氯化镉对泥鳅二倍体和三倍体细胞系具有细胞毒性和遗传毒性，且二倍体细胞系较三倍体细胞系对氯化镉更为敏感。

Cytotoxicity of Cadmium Chloride to Loach Fin Diploid and Triploid Cell Lines in Vitro

In this study, 60-80 generation of loach fin diploid cell line (DIMF) and triploid cell line (TRMF) were used to assess toxicity of cadmium chloride in vitro, and the toxicity characteristics between different ploidies were compared. Semi-lethal concentrations were determined with MTT method; cytotoxicity and genotoxicity were studied through enzyme activity test, micronucleus rate test, and real-time quantitative PCR. Results showed that semi-lethal concentration of DIMF and TRMF was 24.0±0.7μmol/L and 27.3±1.3μmol/L, respectively. Activities of SOD and GSH-Px firstly increased, and then decreased. The activity of GST decreased progressively with the increase of cadmium chloride concentration. Micronucleus rates increased firstly and then decreased with the increase of cadmium chloride concentration, and the maximum micronucleus rate of DIMF and TRMF was 7.33 ± 0.33‰and 8.33 ± 0.67‰, respectively. Relative expression level of MT significantly increased when DIMF and TRMF were exposed by cadmium chloride. The maximum expression levels (55.6 and 57.6 folds of those in control) occurred when cadmium chloride concentration was 30 μmol/L. All results indicated that cytotoxicity and genotoxicity could be detected in DIMF and TRMF subjected to cadmium chloride, and DIMF was more sensitive to cadmium chloride than TRMF.