Original Article
Protective effects of remote ischemic preconditioning in isolated rat hearts
Xiao Teng1, Xin Yuan1*, Yue Tang1*, Jingqian Shi2
1State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases,
Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China; 2Beijing Hospital, Beijing 100730, China. *Equal contributors.
Received June 8, 2015; Accepted July 28, 2015; Epub August 15, 2015; Published August 30, 2015
Abstract: To use Langendorff model to investigate whether remote ischemic preconditioning (RIPC) attenuates post-ischemic mechanical dysfunction on isolated rat heart and to explore possible mechanisms. SD rats were randomly divided into RIPC group, RIPC + norepinephrine (NE) depletion group, RIPC + pertussis toxin (PTX) pretreatment group, ischemia/reperfusion group without treatment (ischemia group) and time control (TC) group. RIPC was achieved through interrupted occlusion of anterior mesenteric artery. Then, Langendorff model was established using routine methods. Heart function was tested; immunohistochemistry and ELISA methods were used to detect various indices related to myocardial injury. Compared with ischemia group in which the hemodynamic parameters deteriorated significantly, heart function recovered to a certain degree among the RIPC, RIPC + NE depletion, and RIPC + PTX groups (P<0.05). More apoptotic nuclei were observed in ischemia group than in the other three groups (P<0.05); more apoptotic nuclei were detected in NE depletion and PTX groups than in RIPC group (P<0.05). While,there was no significant difference between NE depletion and PTX groups. In conclusion, RIPC protection on I/R myocardium extends to the period after hearts are isolated. NE and PTX-sensitive inhibitory G protein might have a role in the protection process.
Keywords: Remote ischemic preconditioning, norepinephrine, heart transplantation, heart function