Effects Of Different Degree Acute Normovolemic Hemodilution On Myocardial Enzyme And Tumor Necrosis Factor-α In Rabbits

Objectives To observe the influence of acute normovolemic hemodilution on myocardial enzyme and tumor necrosis factor-αin rabbits,and then study the injury of different degree acute normovolemic hemodilution on rabbits'heart.Methods Twenty-four healthy rabbits were anesthetized with 20% urethane 5ml·kg-1 and mechanically ventilated(vt =15ml kg-1 ,f=30 bpm).Body temperature were maintained on 37oC. Left jugular artery was cannulated for BP, bood sample collection.Right jugular vein was cannulated for monitoring CVP. Left femoral artery and vein were cannulated for hemodilution.Hemodilution were performed at 30 min following the empirical formula..Blood were withdrawn from femoral artery and simultaneously replaced by intravenous infusion of equal volume of 6% HES until achieving target Hct. The animals were randomly divided into 4equal groups with 6 animals in each group:Ⅰcontrol group was without hemodilution; groupⅡwhich Hct was 24%; groupⅢwhich Hct was 18%; groupⅣwhich Hct was 12%. Blood sample were taken before hemodilution,and at 2 hours,4 hours and 8 hours after hemodilution for determination of plasma CK,CKMB,LDH and TNF-α.At the end of the experiment,myocardial tissue was obtained for microscopic examination.Results In groupⅣ,the plasma CK activities at T3 were significantly higher than T0(P<0.05),and were higher than the others groups at T3(P<0.05).The plasma CKMB activities at T2 and T3 in groupⅣwere higher than baseline(T0)(P<0.05).The plasma LDH activities at T3 in groupⅡ,Ⅲ,Ⅳwere higher than T3 in groupⅠ(P<0.05).The plasma LDH activities at T1 to T3 in groupⅣwere higher than the same moment in groupⅠ(P<0.05).The plasma levels of TNF-αwere significantly increased compared to baseline(T0)( P<0.05) at T2,T3 in groupⅢ,Ⅳ,T1 in groupⅣ.Conclusions While the hematocrit of ANH became lower,the inflammatory factor and myocardial enzyme will step up.