多溴联苯醚对鲫鱼肝脏组织乳酸脱氢酶及同工酶的影响

Effects of polybrominated diphenyl ethers on the activity and isoenzymes of lactate dehydrgenase in the Carassius auratus liver

以鲫鱼(Carassius auratus)为试验材料,研究了经不同浓度的2,2’,4,4’-四溴联苯醚(PBDE-47)和十溴联苯醚(PBDE-209)连续暴露后,鲫鱼肝脏组织中乳酸脱氢酶(LDH)活性及其同工酶谱的动态变化。结果表明,采用质量浓度为0.10～5.00 mg/L的PBDE-47和质量浓度为10.0～50.0 mg/L的PBDE-209对鲫鱼进行水质接触染毒,在试验的10 d内,除了0.10 mg/L的PBDE-47试验组外,其余各组鲫鱼肝脏组织中的LDH活性都发生了明显的动态变化(p<0.01),呈先升高后降低的趋势,在试验的第4～6 d达到峰值,LDH活性与多溴联苯醚(PBDEs)之间的剂量-效应关系并不显著;鲫鱼肝脏组织的LDH同工酶谱也发生了明显变化,不仅同工酶的谱带数有所增加,而且着色明显加深。研究表明,LDH及其同工酶可作为污染生物标志物来评价多溴联苯醚对鱼类肝脏组织的损伤及其生化毒性效应。

The present paper intends to introduce its authors＇ experimental research on the toxic effects of tetrabromodiphenyl ether （PBDE-47） and decabromodiphenyl ether （PBDE-209） on the activi-ties of lactate dehydrogenase （LDH） and spectrum of LDH isoenzymes in the liver of Carassius auratus exposed to PBDE-47 and PBDE-209. For the research purpose, we have deliberately put the fishes under test back to water with the concentration of PBDE-47 being 0.10 - 5.0 mg/L and PBDE-209 being 10.0 - 50.0 mg/L. The activity of LDH in the liver of Carassius auratus was then analyzed every 2 - 4 days in a 10 days exposure period at the temperature of 22 ℃. The results of our experiments prove that the normal value of LDH in the liver of Carassius auratus was （284：1： 6.20） U/g prot. Both the test group of 0.1 mg/L PBDE-47 and the solvent control group had no effects on LDH in the liver after being treated 10 days later. Furthermore, no significant difference （ p 〉 0.05） was found between the control and testing group with 0.10 mg/L PBDE-47. On the contrary, a very significant inhibition （p 〈 0.01） to the activity of LDH was observed in the remaining test groups, especially in those exposed to 〉 0.10 mg/L PBDE-47 and 10.0 mg/L PBDE-209, though no obvious concentration-dependent negative correlation was detected with both the PBDE congeners. During the tested period, the activity of LDH tended to increase at first, and then began to go down. LDH eould reaeh the highest value within 4 - 6 days. The ex- periments also show that the spectrum of LDH in liver could be changed. After the test, the spectrum of LDH was found with specific bands, deeply stained and broad. The results can clearly indicate that LDH and the spectrum of its isoenzymes in the fish livers can be taken as a biomarker to assess the biochemical toxicity of polybrominated diphenyl ethers.