Cariporide Pretreatment Attenuates Lung Ischemia-Reperfusion Injury in Rabbits

Objective To explore the effects of selective Na⁺/H⁺ exchanger antagonist Cariporide on ischemia-reperfusion induced lung injury. Methods Twenty four New Zealand White rabbits with lung ischemia-reperfusion model were established and randomly divided into four groups (n=6 per group) including sham group (S group), ischemia-reperfusion group (IR group), low potassium dextran group (LPD group) and Cariporide group (HOE group). Blood and lung tissue samples were obtained for blood gas, biochemical analyses and histologic examination. Results Systemic administration of HOE increased oxygenation index (arterial oxygen tension/fraction of inspire oxygen, PaO₂ /FiO₂ ) and superoxide dismutase （SOD） activities, while decreased malondialdehyde （MDA） contents, proinflammatory cytokines and natrium hydrogen exchanger-1 （NHE1） expressions, along with the reduction of lung water content （LWC） except for histologic evaluation scores (P<0.05, versus IR group and LPD group). Conclusion Systemic administration of Cariporide before ischemia could protects the lung from ischemia-reperfusion injury via decreasing NHE1 expression. The protective effect seems to be closely related to regulating intracellular calcium overload, oxidative damage and antioxidant enzyme activities and neutrophil infiltration.