Effects Of L-Arginine On Plasma Levels Of Cytokines And Cardiac Troponin I After Cardiopulmonary Bypass

Background: Cardiopulmonary bypass(CPB) induces the release of inflammatory cytokines that play an important role in systemic inflammatory response and endothelial cell injury; result in systemic insult .The effects of CPB were secondary to the exposure of blood to abnormal surfaces in the bypass circuit the activation of complement and the formation of an antigen-antibody complex. L-argmine is a kind of essential amino acid with numerous roles in cellular metabolism including nitric oxide (NO) creatine, polyamine biosynthesis. NO is synthesized by the vascular endothelium through the conversion of L-arginine by the enzyme NO synthase. L-arginine can reduce systemic inflammatory responses after CPB and decrease myocardiac reperfusion injury. This study evaluates the effect of L-arginine by means of comparing tumor necrosis factor α(TNF-α), interleukin-6 (IL-6).cardiac troponin I (cTnl) and interleukin-2 (IL-2) levels ofboth groups after CPB.Methods: 26 patients with rheumatic heat disease were dividedinto two groups randomizer/: (1) treated group (group A,n=13), given L-arginine at 200mg/kg; (2)control group (groupB, n-13). Blood samples for cTnl TNF- a ? IL-6 andIL-2analysis were collected before cardiopuhnonary bypass(CPB) and at 2 and 24 h after initiation of CPB byenzyme-linked immunosorbent assay technique.Result:1.There were no operative complications, no reoperations forbleeding.2.A significant (P<0.05) increase of TNF- a and IL-6 occuredin both group at 2 hour and 24 hours after CPB whencompared with the same group at basline before CPB;in groupA, TNF- and IL-6 levels were significant lower than ingroup B(P<0.05) at 24 hours after CPB.3. A significant (P<0.05) decrease of IL-2 occured in group Aonly at 2 hours and group B at 2,24 hours after CPB. whencompared with the same group at basline before CPB. Therewas no significant differences between group A and group Bbut L-Arginine may shorten the period of IL-2 concentrationrefreshment to its level of preoperation.4. In all patients in group A and group B cTnl concentrationsincreased after CPB when compared with the same groupat basline before CPB.(P<0.05); in group A,cTnI level wassignificant lower than in group B(P<0.05) at 2,24 hours afterCPB.