RESUMEN
Objective To investigate the effect of matrix metalloproteinases(MMPs) in ventilator-induced lung injury inflammatory reaction of newborn rabbits.Methods Seventy-five newborn rabbits aged 1-5 days were randomly arranged to 3 groups:control group(n=3),other 72 rabbits designed by 2?2?3 factorial were divided into high concentration oxygen(100%)and low concentration oxygen(45%) groups,and each group was subdivided into 2 groups:High peak inspiratory pressure(PIP)group and low PIP group.All rabbits were done by mechanical ventilation and killed to obtain lung tissue at 1,3,6 hours after trailing respectively.The concentration of MMP-9 and MMP-2 in lung tissue bomogenate were detected by ELISA,at the same time the ratio of wet to dry was detected and pathological section was analyzed.Results 1.The concentration of MMP-2 in high concentration oxygen group,high PIP group and low PIP group increased compared with that in normal group,and there were significant differences.2.The mean concentration of MMP-9 was lower in high concentration oxygen group than that in normal control group,and there was significant difference between 2 groups.The mean concentration of MMP-9 in low concentration oxygen group was higher than that in normal group,and there was no significant difference between 2 groups.There was no significant difference in effect to mean concentration of MMP-9 by different PIP.3.There were positive correlation between MMP-2 and MMP-9,MMP-2 and the ratio of wet to dry in lung.Conclusions Within 6 hours in newborn rabbits by mechanical ventilation,ventilation with high concentration oxygen up-regulate MMP-2,but down-regulated MMP-9.The lungs stretch by mechanical ventilation increase MMP-9,but decrease MMP-2.Mechanical ventilation can affect the synthesis of MMPs,and MMPs plays an important role in ventilator-induced lung injury of newborn rabbits.