PM2.5-induced Cardiovascular Toxic Effects And Intervention Of Fish Oil And Vitamin E

BackgroundIn recent years,haze occurs frequently in China.Its main reason is the high concentration of fine particulate matter(PM2.5).PM2.5 is directly related to the mortality and morbidity of cardiovascular disease.For quite a long time in the future,most of the residents in our country will still suffer from the harm of haze.So it is imperative to make a thorough inquiry to the harming health effect and its mechanism from PM2.5 and to find the appropriate antagonist.ObjectiveTo anaiysis the toxic effects of PM2.5 exposure on cardiovascular system in rats and intervention effect of fish oil and vitamin E by observing the autonomic nervous system,inflammatory reaction,oxidative stress,endothelial dysfunction,coagulation function,myocardial injury,and myocardial and aorta abdominalis pathology between the experimental group and the control group of rats.MethodsPM2.5 Suspension Preparation: Acetate membranes are used to collect PM2.5 samples of Xinxiang city from November 2015 to March 2016,and the dried samples are diluted by 0.9% sterilized physiological saline.Laboratory animals and our treatment:64 clean(SPF)grade Wistar male rats were randomly divided into 8 groups,The 8 groups were normal saline control group,PM2.5 poisoned group,solvent(corn oil)control group,solvent+PM2.5 poisoned group,fish oil control group,fish oil+PM2.5 poisoned group,vitamin E control group and vitamin E+PM2.5 poisoned group,8 rats in each group.All the rats in the normal saline group,the solvent group,the fish oil group and the vitamin E group were treated with corresponding intragastric administration for 3 weeks and then given saline intratracheal instillation and while the rats in the PM2.5 poisoned group were given PM2.5 through gavage and intratracheal instillation,1 times a day,a total of 3 times.During the experimental process,the rats body weight and other basic conditions of rats were closely observed and recorded.All rats were anesthetized after the last exposure at the end of 24 hours,and the body surface electrocardiogram was recorded.The changes of HRV and average heart rate were analyzed.From the abdominal aorta collected the blood sample and killed all the animals.Blood samples were preserved.To determine CRP,IL-6,ET-1 and P-selectin by ELISA,8-epi-PGF2 by chemiluminescence method,LDH by microplate method,pathological histology of the left cardiac and abdominal aorta were observed with HE staining.Results(1)General conditions :During the experiment,all rats had no death;during the first 3 weeks of intragastric administration,the 8 groups in the body weight growth trend and amplitude were probably the same;during the fourth weeks of intratracheal instillation,the body weight growth trend of the rats in four PM2.5 exposure groups became smaller than that of respective control groups.(2)HRV and average heart rate change :Compared with the NS control group,the HRV indexes of PM2.5 exposure group include SDNN,RMSSD,LF and HF were significantly decrease,while the average heart rate increase(P<0.05);The HRV indexes of fish oil+PM2.5 poisoned group were higher and the average heart rate was lower than the PM2.5 poisoned group(P<0.05);The HRV indexes of Vit-E+PM2.5 poisoned group have no statistical significance with PM2.5 poisoned group(P>0.05).(3)Blood biochemical index changes: Compared with the PM2.5 poisoned group,levels of CRP,IL-6,ET-1,P-selectin,8-epi-PGF2α and LDH of NS control group were significant lower(P<0.05),there were no significant difference between the NS control group and the other three control groups(P>0.05).Levels of CRP,IL-6,8-epi-PGF2α,ET-1,P-selectin and LDH of fish oil+PM2.5 poisoned group were significant lower than the PM2.5 poisoned group(P<0.05);Levels of P-selectin and LDH was slightly lower PM2.5 poisoned group(all P<0.05).levels of CK-MB of different groups have no statistical significance(all P > 0.05).(4)Pathological change: The myocardial pathological of four control groups did not see apparently unusual,The myocardial pathological of PM2.5 poisoned group found that:Epicardial edema and infiltration of inflammatory cells,myocardial cell vacuoles degeneration and vasodilation between myocardial congestion.Fish oil intervention alleviated the above pathological changes,Vit-E intervention also did.Abdominal aortic pathology of all intervention groups had no significant change.Conclusion1.PM2.5 exposure causes cardiovascular toxic effect in rats: represented as decreased heart rate variability,increased inflammatory cytokines CRP and IL-6,elevated oxidative stress maker 8-epi-PGF2α,increased endothelial damage indicator ET-1 and fibrinogen index P-selectin,raised myocardial injury index LDH.The pathologic changes of myocardial tissue included congestion in mesenchyma,epicardial edema and infiltration of inflammatory cells and myocardial cell vacuoles degeneration.2.Fish oil can effective antagonize the toxic effects of PM2.5 exposure.Vit-E have partial antagonistic effect on the toxic effects of PM2.5 exposure(P-selectin,LDH and myocardial pathological).