The Effects Of δ-Opioid Peptide Administration Before CPB On Ischemia-Reperfusion Injury In Pig Lung

Following cardiopulmonary bypass(CPB) or lung transplantation, Lung injury is a significant clinical problem. Lung ischemia-reperfusion(I-R) injury is a major cause of all factors responsible for respiratory dysfunction, even respiratory failure, which affect the effect of surgical operation, even leading to death.Since 1980s, Several reports showed that opioid provided a protective effect in several organs by activating specific opioid receptors. But it was until 1995 that people recognized that opioid might involve in the ischemic precondition(IPC). Although, IPC provided the protection on tissue from I-R injury, It was not easy to take IPC during operation.Administering opioid receptor agonist performs the similar effect as IPC attracted people's interests.Objective The purpose of this study was undertaken to evaluate the role of δ-opioid receptor and [D-Ala²-D-Leu⁵]-enkephaline(DADLE), a δ-opioid receptor agonist, on pulmonary I-R injury after CPB, and to evaluate some of plausible mechanisms concerning the protection of δ-opioid receptor agonist and the interactions with Glibenclamide,a K_ATP channel closer.Material and Methods Thirty-five male pigs, weighting 25-35 Kg, were used in this study. The swines were anesthetized with intramusclar atropine 0.5mg and intravenous 3% pentobarbital 3-5mg?Kg^-1,tracheostomized and mechanically ventilated (V_T 15-20 ml?Kg^-1, RR 16bpm,FiO₂ 100%). Right femoral artery was cannualated for blood pressure monitoring and blood sampling. Routine CPB was used in four groups,the mean times of CPB was 110 mins in...