Introduction and objectives Ischemia and ischemia/reperfusion can dephosphorylate and redistribute Connexin 43 (Cx43). But it is unknown whether no-reflow phenomenon has an effect on the expression and distribution of Cx43 after acute infarction and reperfusion.

Methods 21 open-chest pigs were divided into three groups. Left anterior descending artery (LAD) occlusion for 90 min before 180 min of reperfusion was made in ischemia/reperfusion group. The pigs in ischemia groups were either subjected to a 90 min or 270 min LAD ligation. No-reflow and risk regions were determined pathologically by dye staining. Cx43 expression was measured by western blotting and quantitative RT-PCR analysis. Cx43 spacial distribution was shown by immunofluorescence examination.

Results The content of phosphorylated and mRNA of Cx43 was higher in reflow region than in no-reflow and sustained ischemic region. The distribution of Cx43 was also altered in no-reflow region.