[The protective effects of ischemia preconditioning on the lung injury following with limbs ischemia/reperfusion].

OBJECTIVE: To explore the protective effects of ischemic preconditioning (IPC) on the lung injury following with limbs ischemia /reperfusion (LI/R). METHODS: The models of LI/R injury were constructed in rabbits. The blood from right external jugular vein and left common carotid artery, into and out-flowing pulmonary blood (IPB, OPB) respectively. Superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO) in IPB and OPB and lung tissues were measured, as well as total nitric oxide synthase (tNOS) and inducible nitric oxide synthase (iNOS) in lung tissues were detected in different groups. The effects of IPC on the lung injury were observed. RESULTS: Compared with sham and before ischemic, the activity of SOD decreased and the content of MDA and NO increased after 4 h ischemia followed by 4 h reperfusion in IPB, OPB and lung tissues. The activity of tNOS and iNOS in lung tissues increased remarkably as well, there was statistical significance (P < 0.05, P < 0.01). SOD increased and MDA, NO, tNOS, iNOS decreased significantly by IPC before ischemia/reperfusion. The correlation analysis indicated that MDA was negatively correlated with SOD and was positively correlated with MDA, NO, iNOS (P < 0.01). CONCLUSION: Oxygen free radicals metabolic confusion of lung occurred in the course of LI/R, IPC could strengthen the resistance of peroxidation in lung and had protective effects on the lung injury following with LI/R.