Experimental Study OfT He Portective Function On Myocardial Injury Of ω-3Polyunsatuarted Fatty Acids In Seirously Bunred Rats

Objective: To investigate the protective function on myocardial and effect onultrastructural changes of myocardial cells of ω-3polyunsaturated fatty acids inseriously burned rats.Method: A total of72SD rats with30%total body surface area(TBSA) full thicknessburn were randomly divided into3groups:(1) normal control group (A group,n=8);(2)the experimental group (B group,n=32)(3)treatment group (C group,n=32). A groupof rats was injected NS with2mL/(kg d) by tail vein, B、C group of rats was injected20%middle-long-chain fatty emulsion1mL/(kg·d)or ω-3fish oil with2mL/(kg d)by tail vein at the same time every day.Before injury group (A group) and after injurygroups (C group, B group) were measured respectively the levels of serum IL-6, TNF-αand cardiac troponin T (cTnI)，observed morphological changes of cardiac musculartissue by normal light and TEM, expression level of NF-κBp65in cardiac musculartissue were detected by immunohistochemical staining. The expression of myocardialTNF-αmRNA was assessed by RT-PCR. Each subgroup was8rats.Results:1.The levels of TNF-α and IL-6in the blood serum of B group and C groupwere significantly higher than the normal control group (P<0．01).The levels of TNF-αand IL-6of the C group were lower than those of B group at postburn4d,7d,10d（P<0.05or P<0.01）.2.The levels of cTnI of the B group and the C group weresignificantly upper than the normal control group(A group) at every phase point(P<0．01); Compared with B group,the levels of cTnI of C group were obviouslylower at postburn4d,7d10d (P<0．05).3. The damage in the myocardium of Cgroup was less than B group observed by transmission electron microscope, whileexisted in both B group and C group in comparision with A group.4.Theexpression levels of NF-κBp65in cardiac muscular tissue of B group and C group were higher than those of A group detected by immunohistochemical staining.Compared with B group, expression levels in C group declined（P<0.05）.5. Theexpression levels of myocardial TNF-αmRNA enhanced significantly in contrast withthose of A group（P<0.01）, expression levels of C group decreased at postburn4d,7d phase point in comparision with those of B group（P<0.05）.Conclusion:1. ω-3PUFAs reduce the releasing of pro-inflammatory media,exampleIL-6, TNF-α to promote immune dysfunction after burn.2. ω-3PUFAs effectivelyreduces the expression of NF-κBp65in cardiac muscular tissue byimmunohistochemical method and TNF-αmRNA by RT-PCR.3. ω-3PUFAs reduce thelevels of cTnI, improve the injury of cardiocytes,and protect the myocardium.4.The anti-inflammatory mechanism of the ω-3PUFAs may due to blocking theactivating of signal path of NF-κB consequently reducing productions of the variousinflammation mediators.ω-3PUFAs may protect cardiocyte and improve heart functionvia anti-inflammatory after sever burn.