Dieldrin对PC12细胞的增殖及酪氨酸羧化酶mRNA表达的影响

目的 :观察有机氯杀虫剂dieldrin对培养的PC12细胞增殖及对其酪氨酸羟化酶mRNA(THmRNA)表达的影响 ,探讨该毒物致帕金森病 (PD)的可能机制。方法 :以MPP+ 为阳性对照 ,用不同浓度 (10 -4 ～ 1mmol·L-1)的MPP+ 和dieldrin分别于预PC12细胞 2 4h后计细胞数 ,并采用半定量逆转录聚合酶链式反应 (RT PCR)方法测定THmRNA表达的改变。结果 :(1)MPP+ 和dieldrin对PC12细胞均有毒性 ,1mmol·L-1的MPP+ 可使细胞数减少至对照组的 45 % (P <0 0 1) ,低于此浓度的MPP+ 对细胞增殖无影响 ;但 0 1mmol·L-1的dieldrin就可使细胞数减少至对照组的 3 0 % (P <0 0 1) ,1mmol·L-1的dieldrin使PC12细胞全部死亡。 (2 )MPP+ 和dieldrin均可降低THmRNA的表达。 0 1mmol·L-1MPP+ 和dieldrin使细胞THmRNA的表达分别下降至对照组的 69 3 % (P >0 0 5 )和 61 7% (P <0 0 1)。结论 :Dieldrin不仅具有与MPP+ 相同的抑制培养的PC12细胞的增殖及THmRNA表达的作用 ,而且其对细胞的毒性强于MPP+ ,提示dieldrin是一种潜在的致PD物质 ,其与PD的关系值得进一步研究

Effects of Dieldrin on the Proliferation of PC12 Cell and the Expression of Tyrosine Hydroxylase mRNA

Aim: To evaluate the possible pathogenesis of dieldrin by measuring the PC12 cell survival and the expression of tyrosine hydroxylasc mRNA (THmRNA) after incubation with dieldrin for 24h. Methods:PC12 cella were selected in this study. MPP+ was used as a positive control.After 24h of growth, various concentrations of MPP+ and dieldrin ( 10-4～1 mmol· L-1) were added to the growth medium for 24h. PC12 cell survival was examined and the expression of THmRNA was measured by using RT-PCR. Resnlts: (1) Both MPP+ and dieldrin had toxic effects on PC12 cell. The PC12 cell survival signifiantly decreased to 45 % of the control after incubation with 1 mmol·L- 1 MPP+ for 24h. However, MPP+had no effect on cell survival when its concentration was lower than 1 mmol· L-1. The PC12 cell survival significantly decreased to 30% ( P<0.01 ) of the control after incubation with 0.1 mml·L-1 dieldrin for 24 h. Morever, after treating with 1 mmol· L-1 dieldrin for 24h, the PC12 cells were totally dead. (2) Both MPP+ and dieldrin had toxic effects on the expression ofTHmRNA. When PC12 cells were incubated with 0.1 mmol·L-1MMP+ and dieldrin for24 h, the exptessions of THmRNA were decreased to 69.3% (P>0.05) and 61.7% (P<0.01) of the control,respectively. Conclusion:Dieldrin, which has stronger toxic effects on PC12 cell survival and the expression of THmRNA than MPP+ ,may be apotential etiological agent for parkisonism.