Resveratrol restored the structural and functional association between M3 receptor and connexin 43 gap junction proteins in ischemia-reperfusion injury of isolated rat heart / 药学学报

This study is to explore whether the protective effect of resveratrol on ischemia-reperfusion injury is correlated with the structural and functional association between M3 receptor (M3 subtype of muscarinic acetylcholine receptor) and Cx43 (connexin 43 gap junction proteins). Immunoprecipitation, immunoblotting and immunofluorescence were applied to investigate whether resveratrol has an effect on structural and functional association between M3 and Cx43. The effect of resveratrol on electrocardiogram Lead II ex vivo in rats, SOD (superoxide dismutase) activity and MDA (malondialdehyde) content was also observed in order to evaluate the protective effect of resveratrol on ischemia-reperfusion injury. Resveratrol could restore the structural and functional association between M3 receptor and Cx43 gap junction proteins that was partially destroyed under ischemia-reperfusion injury. The phosphorylation and spatial distribution disturbances in Cx43 expression caused by ischemia-reperfusion injury were also restored. Also, the QRS duration, SOD activity and MDA content were restored. Resveratrol could restore the structural and functional association between M3 receptor and Cx43 gap junction proteins.

Integration between M3 muscarinic acetylcholine receptor and connexin 43 as antiarrhythmic targets in rat ventricular myocardium / 药学学报

<p><b>AIM</b>To optimize the method of investigating structural integration between proteins and study the integration between arrhythmia related proteins in molecular level.</p><p><b>METHODS</b>Immunostaining the normal ventricular myocytes was used to observe the distribution of connexin 43 and muscarinic acetylcholine receptor (mAChR). The five mAChR subtypes were precipitated using immunoprecipitation. Then, SDS-PAGE and Western blotting with the anti-connexin 43 antibody were performed to observe whether they were structurally integrated. Further, different concentrations of detergent were used to observe whether this relationship could be broken.</p><p><b>RESULTS</b>The five subtypes of mAChR existed in the cardiac myocyte of the rat, and all the five mAChR subtypes combined with connexin 43. In the normal rat ventricular myocyte membrane, connexin 43 and M3 receptor are co-located. When adding certain concentration of detergent to the membrane protein, the integration between M3 receptor and connexin 43 was broken, and the phosphorylated form of connexin 43 integrated with M3 receptor.</p><p><b>CONCLUSION</b>The results indicated that the structural integration between mAChR and phosphorylation of connexin 43 existed in rat ventricular myocardium, and this integration could be broken by certain concentration of detergent.</p>