The Role Of Endoplasmic Reticulum Stress In Acrylonitrile-induced Liver Damage In Rats

Objective:To study the effect of ACN on oxidative damage induced by ACN in ERS signaling pathways and the effect of NAC on hepatic injury induced by ACN,to explore the toxic mechanism of ACN in liver injury.Methods: 50 healthy adult male SD rats weighing 250~300g were randomly divided into5 groups,10 rats in each group,with 12.5,25,50.0mg/kg ACN gavage,NAC group were treated by intragastric administration of 300.0mg/kg NAC after 30 minutes of reperfusion 50.0mg/kg ACN,control group 0.5ml/100 g in corn oil by gavage,1times/day,6 days/week,a total of 13 weeks.After the end of exposure,the rats were sacrificed by cervical dislocation.(1)The liver tissue of rats was isolated and weighed,and the liver organ coefficient was calculated.(2)The contents of GSH,SOD activity,GSH-Px activity,CAT activity and MDA content in liver tissue were measured by spectrophotometry method.(3)The expression of ERS-related genes GRP78,PERK,CHOP and caspase-12 mRNA in liver tissue were detected by RT-PCR.(4)Western Blot was used to detect the expression of endoplasmic reticulum stress related protein GRP78,eif2?,p-eif2?,CHOP in liver tissue.Results:(1)The organ coefficient of liver in the middle and high ACN groups were higher than that in the control group,the differences were statistically significant(P<0.05).(2)The content of GSH in the low and middle ACN group were significantly decreased compared to control group(P<0.05);The activity of GSH-Px in the low ACN group was significantly increased compared to control group(P<0.05);The activity of SOD and the content of MDA in low and middle ACN groups were increased significantly compared to control group(P<0.05).;The activity of CAT in middle and high ACN groups were decreased significantly,compared to control group(P<0.05).The content of GSH in the liver of the NAC group was higher than that of the high ACN group(P<0.05);MDA content and SOD activity were significantly lower than those of the high ACN group(P<0.05),the differences werestatistically significant(P<0.05).The activity of GSH-Px and CAT activity were higher than those of high ACN group,but the differences were not statistically significant(P>0.05).(3)RT-PCR results showed that GRP78,PERK,CHOP and caspase-12 mRNA expression levels in the liver of high ACN exposure group were higher than those in control group,the differences were statistically significant(P<0.05).The expression of PERK,CHOP and caspase-12 m RNA in the liver of NAC group were significantly lower than those in the high ACN group(P<0.05).The expression of GRP78 mRNA in the liver of NAC group was lower than that in the high ACN group,but the difference was not statistically significant(P>0.05).(4)The results of Western Blot showed that the expression levels of GRP78,p-eif2?/eif2?,CHOP and caspase-12 protein in the high ACN group were significantly higher than those in the control group,and the differences were statistically significant(P<0.05).The expression levels of GRP78,p-eif2?/eif2?,CHOP,caspase-12 protein in NAC group were lower than that in high ACN exposure group,the difference were statistically significant(P<0.05).Conclusion: Chronic exposure to ACN could cause oxidative damage on rat liver,and then ERS signaling pathway was activated by up-regulate the expression of ERS-related genes GRP78,PERK,CHOP and caspase12 m RNA and GRP78,p-eif2?/eif2?,CHOP,caspase-12 protein expression level.NAC could reduce the degree of oxidative damage and antagonize the ERS signaling pathway.It's suggested that ROS plays an important role in liver injury and ERS signaling pathway induced by ACN.