The Clinical Study On The Protective Effects Of Fructose-1, 6-Diphosphate On Pulmonary Ischemia-Reperfusion Injury In Infants

Objective To explore the protective effects and possible mechanism of fructose-1,6-diphosphate(FDP) preconditioning and postconditioning on CPB-induced pulmonary ischemia-reperfusion injury(PIRI) in infants.And compare the protective effctcs of this two.Methods Thirty-nine infants with congenital heart defects undergoing cardiac surgery under cardiopulmonary bypass(CPB) were randomly divided into three groups with 13 cases each:control groups(CG),FDP preconditioning group(FDPⅠG),FDP postconditioning group(FDPⅡG).In FDP I G,FDP(200mg/kg) was injected into the internal jugular vein after induction of anesthesia and before beginning of CPB,5 minutes later,start CPB.In FDPⅡG,FDP(200mg/kg) was injected into the internal jugular vein at the start of aortic cross clamp was opened.In CG,the same volume of normal saline instead of FDP was infused through the same path before CPB.Blood sample were taken to determine the plasma superoxide dismutase(SOD) activity,the plasma concentrations of maleic dialdehyde(MDA) before operation(T1),at 15 rain after aortic cross clamp(T2) and at 20 minutes(T3),3 hours(T4),24hours(T5) after aortic cross clamp was opened.The plasma concentrations of NO and surfactant-associated proteins A(SP-A) were measured at T1 and T4.Respiratory index(RI) were calculated by the results of arterial blood gas analysis at T1,T3,T4,T5.Lung tissue of 5 patients in each groups were taken randomly before closing thoracic cavity.Lung tissue structural changes were observed under light microscope,as well as the expression of nuclear factor-κB(NF-κB) of lung tissue by immunohistochemical method.Record mechanical ventilation time of every patients after operation.Results The difference of the three groups were not statistically significant at TI(P＞0.05).Compared with CG,In FDPⅠG and FDPⅡG,the plasma SOD activity increased, MDA concentration decreased at T3,T4,T5,NO concentration increased,SP-A concentration decreased at T4,RI decreased at T3,T4,T5,the NF-κB activity of lung tissue weakened,their gray value increased,these difference are significant(P＜0.05).By observe lung tissue pathology changes under light microscope,we found that in CG alveolar structure damage significantly,there were lots of effusion and bleeding in alveolar space,many polymorphonuclear infiltrated lung tissue.In the two FDP groups,the alveolar structure were complete relatively,there were less effusion,bleeding and polymorphonuclear infiltration in lung tissue.FDPⅠG compared with FDPⅡG,the difference about the plasma SOD activity,MDA,NO,SP-A concentration,RI,NF-κB activity of lung tissue were not statistically significant(P＞0.05),difference of lung tissue injury of the two groups were not significant.Mechanical ventilation time of the three groups after operation were not different significantly(P＞0.05).Conclusions 1.FDP preconditioning and FDP postconditioning have obvious protective effect on pulmonary ischemia-reperfusion injury.2.FDP preconditioning and FDP postconditioning have the same protective effect on pulmonary ischemia-reperfusion injury.