title: Cardioprotection of ischemic preconditioning in rats involves upregulating adiponectin.
abstract: It has been reported that ischemic preconditioning (IPC) and adiponectin (APN) are cardioprotective in many cardiovascular disorders. However, whether APN mediates the effect of IPC on myocardial injury has not been elucidated. This study was conducted to investigate whether IPC affects myocardial ischemic injury by increasing APN expression. Male adult rats with cardiac knockdowns of APN and its receptors via intramyocardial small-interfering RNA injection were subjected to IPC and then myocardial infarction (MI) at 24 h after IPC. Globular APN (gAd) was injected at 10 min before MI. APN mRNA and protein levels in myocardium as well as the plasma APN concentration were markedly high at 6 and 12 h after IPC. IPC ameliorated myocardial injury as evidenced by improved cardiac functions and a reduced infarct size. Compared with the control MI group, rats in the IPC + MI group had elevated levels of left ventricular ejection fraction and fractional shortening and a smaller MI size (P< 0.05). However, the aforementioned protective effects were ameliorated in the absence of APN and APN receptors, followed by the inhibition of AMP-activated protein kinase (AMPK) phosphorylation, but reversed by gAd treatment in wild-type rats, and AMPK phosphorylation increased (P< 0.05). Overall, our results suggest that the cardioprotective effects of IPC are partially due to upregulation of APN and provide a further insight into IPC-mediated signaling effects.
authors.affiliation: Department of Intensive Care UnitChina-Japan Friendship Hospital, Beijing, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of CardiologyChina-Japan Friendship Hospital, Beijing, People's Republic of China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Intensive Care UnitChina-Japan Friendship Hospital, Beijing, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Duan
authors.affiliation: Department of Plastic and CosmetologyBeijing Haidian Hospital, Beijing, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Ma
authors.affiliation: Department of Physiology and PathophysiologySchool of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Kong
authors.affiliation: Department of CardiologyChina-Japan Friendship Hospital, Beijing, People's Republic of China.
authors.forename: Yuannan
authors.initials: Y
authors.lastname: Ke
authors.affiliation: Department of Intensive Care UnitChina-Japan Friendship Hospital, Beijing, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of CardiologyChina-Japan Friendship Hospital, Beijing, People's Republic of China victorzheng@sina.com.
authors.forename: Jingang
authors.initials: J
authors.lastname: Zheng
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D052242:Adiponectin / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D005786:Gene Expression Regulation; D006334:Heart Function Tests; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D009203:Myocardial Infarction / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D015428:Myocardial Reperfusion Injury / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D054419:Receptors, Adiponectin / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013318:Stroke Volume / Q000502:physiology
chemical_list: D052242:Adiponectin; C499920:Adipoq protein, rat; D034741:RNA, Small Interfering; D054419:Receptors, Adiponectin; D055372:AMP-Activated Protein Kinases
keywords: adiponectin; gene regulation; ischemia preconditioning; myocardial infarction