TY - JOUR AB - The present study aimed to determine whether post-ischemic treatment with dexmedetomidine (DEX) protected the heart against acute myocardial ischemia/reperfusion (I/R)‑induced injury in rats. The phosphatidylinositol‑3 kinase/protein kinase B(PI3K/Akt)‑dependent signaling pathway was also investigated. Male Sprague Dawley rats (n=64) were subjected to ligation of the left anterior descending artery (LAD), which produced ischemia for 25 min, followed by reperfusion. Following LAD ligation, rats were treated with DEX (5, 10 and 20 µg/kg) or underwent post‑ischemic conditioning, which included three cycles of ischemic insult. In order to determine the role of the PI3K/Akt signaling pathway, wortmannin (Wort), a PI3K inhibitor, was used to treat a group of rats that had also been treated with DEX (20 µg/kg). Post‑reperfusion, lactate dehydrogenase (LDH), cardiac troponin I (cTnI), creatine kinase isoenzymes (CK‑MB), superoxide dismutase (SOD) and malondialdehyde (MDA) serum levels were measured using an ultraviolet spectrophotometer. The protein expression levels of phosphorylated (p)‑Akt, Ser9‑p‑glycogen synthase kinase‑3β (p‑GSK‑3β) and cleaved caspase‑3 were detected in heart tissue by western blotting. The mRNA expression levels of B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein (Bax) were detected using reverse transcription‑polymerase chain reaction. At the end of the experiment, the hearts were removed and perfused in an isolated perfusion heart apparatus with Evans blue (1%) in order to determine the non‑ischemic areas. The risk and infarct areas of the heart were not dyed. As expected, I/R induced myocardial infarction, as determined by the increased serum levels of cTnI, CK‑MB and MDA, and the decreased levels of SOD. Post‑ischemic treatment with DEX increased the expression levels of p‑Akt and p‑GSK‑3β, whereas caspase‑3 expression was reduced following DEX treatment compared with in the I/R group. Compared with the I/R group, the ratio of Bcl‑2/Bax at the mRNA level was elevated in the DEX and ischemic post‑conditioning groups, whereas the expression levels of Bax were decreased. Conversely, the effects of DEX were attenuated by Wort. These results indicated that, similar to post‑ischemic conditioning, post‑ischemic treatment with DEX protects the heart against I/R via the PI3K/Akt‑dependent signaling pathway, possibly by activating GSK‑3β. AD - Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230601, P.R. China Department of Anesthesiology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui 233004, P.R. China Department of Physiology, Bengbu Medical College, Bengbu, Anhui 233030, P.R. China AU - Cheng,Xiang,Yang AU - Gu,Xiao,Yu AU - Gao,Qin AU - Zong,Qiao,Feng AU - Li,Xiao,Hong AU - Zhang,Ye DA - 2016/07/01 DO - 10.3892/mmr.2016.5345 EP - 803 IS - 1 JO - Mol Med Rep KW - dexmedetomidine cardioprotection apoptosis ischemia/reperfusion phosphatidylinositol‑3 kinase/protein kinase B signaling pathway PY - 2016 SN - 1791-2997 1791-3004 SP - 797 ST - Effects of dexmedetomidine postconditioning on myocardial ischemia and the role of the PI3K/Akt-dependent signaling pathway in reperfusion injury T2 - Molecular Medicine Reports TI - Effects of dexmedetomidine postconditioning on myocardial ischemia and the role of the PI3K/Akt-dependent signaling pathway in reperfusion injury UR - https://doi.org/10.3892/mmr.2016.5345 VL - 14 ER -