Effects of biliverdin on lung injury induced by brain death in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of exogenous biliverdin on lung injury induced by brain death (BD) in rats. Methods Twenty-three adult male Wistar rats in which Fogarty balloon catheter was successfully inserted into cranial cavity were randomly divided into 3 groups group Ⅰ sham operation (group S,n = 7); group Ⅱ brain death (group BD, n = 8) and group Ⅲ biliverdin + BD (group B, n = 8). The animals were anesthetized, intubated and mechanically ventilated. Femoral artery and vein were cannulated for MAP monitoring and drug and fluid administration. Brain death was induced by injecting slowly normal saline into the balloon in group Ⅱ and Ⅲ. BD was confirmed by dilated and fixed pupils, apnea, transient hypertension and EEG changes. In group Ⅲ biliverdin 35 mg/kg was injected intraperitoneally as soon as BD was confirmed. The animals were mechanically ventilated for another 1.5 h during which MAP was maintained at 80-120 mm Hg by iv norepinephrine infusion. Arterial blood samples were obtained before anesthesia, immediately before and at 5, 30,60, 90 min after intraperitoneal biliverdin for blood gas analysis and determination of plasma bilirubin concentration. PaO2/FiO2 was calculated. The animals were sacrificed at 1.5 h after biliverdin administration. The left lung was removed for detection of MDA content, SOD activity, total antioxidant capacity, cell apoptosis and biliverdin reductase expression in lung tissue. Results Brain death significantly decreased PaO2/FiO2, lung SOD activity and total antioxidant capacity and increased lung MDA content and apoptosis as compared with sham operation group. IP biliverdin significantly attenuated BD-induced lung injury in group B as compared with group BD. The plasma bilirubin concentration and biliverdin reductase expression were significantly higher in group B than group BD. Conclusion Exogenous biliverdin can attenuate BD-induced lung injury by inhibiting pulmonary oxidative stress response and apoptosis.