镉及α-硫辛酸对大鼠肝脏GJIC功能的影响

Effects of cadmium and α-LA on gap junctional intercellular communication of the rats liver

为探讨镉及α-硫辛酸(α-LA)对大鼠肝细胞缝隙通讯功能(GJIC)的影响,将30只100g左右SD雌性大鼠随机均分为3组:对照组(自由饮水及超纯水灌胃)、镉组(50mg/L醋酸镉自由饮水及超纯水灌胃)、镉与α-LA共同处理组(50mg/L醋酸镉自由饮水及α-LA灌胃50mg/kg)。12周后,采用荧光染料标记传输示踪法(IL/DT)测定GJIC功能,免疫印迹检测大鼠肝脏中Cx43、p-Cx43、Cx32蛋白表达变化,荧光定量PCR法检测大鼠肝脏中Cx32、Cx26、Cx43mRNA表达量的变化。IL/DT结果显示,大鼠长时间饮用醋酸镉后,肝脏细胞间荧光黄两侧扩散距离极显著减少(P<0.01),α-LA处理后极显著提高(P<0.01)。肝脏中Cx43、p-Cx43、Cx32蛋白表达量呈显著或极显著的降低,Cx43、Cx32、Cx26mRNA转录基因表达也呈显著或极显著的降低(P<0.05或P<0.01),α-LA处理后都有显著或极显著升高(P<0.05或P<0.01)。结果表明:长期饮用醋酸镉可以抑制大鼠肝细胞GJIC,可能是连接蛋白或基因表达减少,α-LA能缓解镉对GJIC的影响。

Vivo studies were carried out in 30 female SD rats （100 g） to investigate the toxical effect of cadmium on the function of rat liver, the protect effect of lipoic acid and the regulation role of gap junction intercellular communication （GJIC）. After one week feeding, the rats were allocated randomly to three groups of ten each,including control group rats drinking the DDW （double dis- tilled water） ;the cadmium group rats consumed the CdAc2 （50 mg/L） as drinking water; the cadmium and the α-LA treated group rats consumed the CdAc2 as drinking water, plus lipoic acid （50 mg/kg） by intragastric administration. After 12 weeks treatment,the GJIC of the hepatocyte were detected by the incision loading dye-transfer assay and the Cx43, p-Cx43, Cx32 in the liver were measured by Western blot. The gene transcription levels （Cx43,Cx32,Cx26 mRNA） in liver were measured by fluorescent quantitative-PCR （FQ-PCR）. The results of IL/DT indicated that the function of GJIC in Cd or Cd＋α-LA group were inhibited （P〈0.01）. But the the function of GJIC in Cd ＋ α-LA group was better than the Cd group （P〈0.01）. Compared with the control group, the expression level of Cx43, Cx32 and p-Cx43 levels in the liver of rats decreased significantly （P〈0.05 or P〈0.01） in Cd or Cd＋α-LA grout,. Compared,the Cd group with the relative mRNA transcription levels of Cx43,Cx32,Cx26 were sigificantly lower than that those of the control group （P〈0.05 or P〈0.01）,while the transcription levels of these genes in Cd ＋α-LA group was higher than those of expression of the proteins or gene w acid could reduce these damages to the Cd group （P〈0. 01）. In conclusion,Cd could decrease the hich were associated with the gap junction in liver. The α-lipoic GJIC by Cd.