Effects of rapamycin preconditioning on lung injury induced by limb ischemia-reperfusion in rats / 临床麻醉学杂志

ABSTRACT

Objective To discuss the effects and related mechanisms of rapamycin preconditioning on lung injury induced by limb ischemia-reperfusion (IR) in rats.Methods Sixty healthy male SD rats, aged 4-5 months, weighing 250-300 g, were randomly divided into 5 groups (n=12 each) using a random number table sham operation group (group S);limb ischemia-reperfusion group (group IR);rapamycin 1, 5, 10 mg/kg pretreatment groups (groups R1, R5 and R10).Ischemia-reperfusion of limb was produced by occlusion of bilateral femoral arteries for 2 h followed by 3 h reperfusion.Blood samples were collected to determine serum superoxide dismutase (SOD), malondialdehyde (MDA), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations,1ungs were removed for microscopic examination and for determination of wet/dry lung weight ratio.Results The activity of SOD in groups IR, R1 and R5 was significantly lower than that in group S (P＜0.05).The activity of SOD in groups R1, R5 and R10 was significantly higher than that in group IR, that in groups R5 and R10 was significantly higher than that in group R1, that in group R10 was significantly higher than that in the group R5 (P＜0.05).Serum MDA, IL-1β, IL-6, TNF-α concentrations and wet/dry lung weight ratio were significantly increased in groups IR, R1 and R5 (P＜0.05).Serum MDA, IL-1β, IL-6,TNF-α concentrations and wet/dry lung weight ratio were lower in groups R1, R5 and R10, those in groups R5 and R10 were significantly lower than those in group R1, those in group R10 was significantly lower than those in group R5 (P＜0.05).Compared with group S, the lung tissue injured more significantly in group IR.Compared with group IR, the lung tissue injury gradually reduced in groups R1,R5 and R10.Conclusion Rapamycin pretreatment can reduce lung injury caused by limb ischemia-reperfusion injury in rats in a dose-dependent manner, the greater the dose, the stronger the effect of reducing lung injury caused by limb ischemia-reperfusion injury.The mechanisms may involve attenuating oxidative stress and inhibiting inflammatory response.