Myocardial protection of adiponectin /adiponectin receptor 1 signal pathway in rats with limb ischemic preconditioning / 中华老年医学杂志

ABSTRACT

Objective To investigate the myocardial protection of adiponectin (ADP) /adiponectin receptor 1 (ADPR1) related-signal pathway in rats with limb ischemic preconditioning.Methods Thirty SD male rats were randomly divided into sham-operation group,myocardial ischemia reperfusion injury (MIRI) group,limb ischemic preconditioning (LIPC) group,LY294002 (the PI3-specific inhibitor) pretreatment group and LY294002+LIPC group (n=10 each).The mRNA level of myocardial ADP and ADPR1,the protein expressions of phosphatidylinositol 3-kinase (PI3k)phosphorylated Akt (p-Akt) were determined by RT-PCR and Western blot,respectively. Results As compared with sham-operation group,the mRNA levels of ADP and ADPR1 in MIRI group were significantly decreased (0.53 ± 0.07 vs.0.74 ± 0.08 and 0.52 ± 0.02 vs.0.72 ± 0.04,P＜0.05).Compared with MIRI group,the mRNA levels of ADP (0.72±0.21) and ADPRI (0.80±0.023) in LIPC group were increased,ADP(0.49±0.07) and ADPR1 (0.52± 0.02) mRNA were decreased in LY294002 group (both P＜0.05),but there were no difference in ADP(0.70±0.16) and ADPR1(0.78±0.05) mRNA between LY294002+LIPC group and MIRI group.The protein levels of Pl3k and p-Akt were lower in MIRI group than in sham-operation group (3.85±0.23 vs.2.83±0.22and 3.77±0.32 vs.2.66±0.29,P＜0.05).In contrast to MIRI group,the yield of PI3k (2.65±0.32)and p-Akt(2.26±0.27) protein (P＜0.05) were increased in LIPC group,but there were unproductive protein of PI3k (3.75 ± 0.65) and p-Akt (4.01 ± 0.71) in LY294002 group with no differences versus the levels of PI3k (3.23 ± 0.48) and p-Akt (3.17 ± 0.54) in LY294002 + LIPC group. Conclusions Limb ischemic preconditioning may protect myocardium by promoting serum adiponectin levels,improving myocardial mRNA expressions of ADP and ADPR1,activating the ADP/PI3k/Akt signaling pathway in reperfusion injury.