[Mechanism of heart and lung injury induced by cerebral ischemia/reperfusion in both young and old mice].

Objective To study the mechanism of heart and lung injury after cerebral ischemia/reperfusion in mice. Methods C57BL/6J mice were divided into young and old groups according to their ages, the former being 5-6 months old and the latter being 20-21 months old. Each group was divided into five subgroups subjected to sham operation, middle cerebral artery occlusion for 1-hour ischemia followed by 1-, 12-, 24-, 48-hour reperfusion. At different reperfusion time, HE and TUNEL staining were used to observe the morphological changes of heart and lung tissues; meanwhile, chemical colorimetry was performed to determine the changes of cardiac Na(+)-K(+)-ATPase and Ca(2+)-ATPase; the lung indexes were evaluated; the levels of nuclear factor (NF)-κBp65, p-NF-κBp65, IκBα, p-IκBα were detected by Western blotting; the levels of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α) were determined by ELISA; and the release of NO was examined by colorimetry. Results We observed inflammatory responses in the lung tissues of young and old mice at 24-hour reperfusion and 1-hour reperfusion, respectively, and hemorrhage in the heart tissues of young and old mice at 24-hour reperfusion and 12-hour reperfusion, respectively.Lung tissues showed earlier response to the stimulation of cerebral ischemia/reperfusion than heart tissues did. Meanwhile, the results of Na(+)-K(+)-ATPase, Ca(2+)-ATPase, lung index, NF-κB signaling pathway and inflammatory cytokines in young and old mice were consistent with histological changes of heart and lung tissues. Conclusion Cerebral ischemia/reperfusion can cause heart and lung tissue injury in the old mice, and energy metabolism and inflammation cascade are the main mechanisms of the injury.