Roles of phosphoinositide 3 kinase/serine -threonine kinase signal pathway in cardioprotection of fentanyl postconditioning and limb remote postconditioning

Objective To assess the roles of phosphoinositide 3 kinase/serine-threonine kinase(PI3K/Akt) signal pathway in cardioprotection of fentanyl postconditioning and limb remote postconditioning in an in vivo rat model with myocardial ischemia reperfusion injury.Methods Thirty-two anesthetized male SD rats (weighed 250 g-350 g) were randomly allocated into the four groups:group C (control),group F (fentanyl postconditioning),group R (RIPOC),and group F-R (combined fentanyl postconditioning and RIPOC).All rats were treated with left anterior descending coronary artery(LAD) occluded for 30 min,followed by a 60-min reperfusion (LAD open) in vivo.The Olingo PI3k/Akt signaling pathway microarray (SA Bioscience)and Western-blot technique were used to distinguish the expression of genes related to PI3K/Akt pathway and levels of phosphorylated Akt in myocardial tissue sample from ischemia area.Results Expressions of many detected genes relating to PI3K/Akt signal pathway were significantly different among the four groups.As compared with group C,9 genes showed a significant up-regulated expression in group F,2 genes showed a significant up-regulated expression in group R,and a total number of 33 genes showed a significant up-regulated expression in group F-R.The Western-blot analysis revealed that the expression of phosphorylated Akt in myocardium increased significantly in groups F,R and F-R compared with group C.The expression of phosphorylated Akt in myocardium was also stronger in group F -R than in groups F and R.Conclusions Combined fentanyl postconditioning and RIPOC can produce an enhanced activation of PI3K/Akt signal pathway. Key words: Myocardial ischemia/reperfusion injury;  Cardioprotection;  Remote ischemia postconditioning;  Pharmacological postconditioning;  Opioid;  Phosphoinositide 3 kinase/serine-threonine kinase signal pathway