The effects of various beta-blockers on myocardial gap junction structure in rat with myocardial ischemia-reperfusion injury / 中华心血管病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To compare the effects of carvedilol, metoprolol and propranolol on myocardial gap junction (GJ) structure in rat with myocardial ischemia and reperfusion injury.</p><p><b>METHODS</b>Rats were divided randomly into five groups sham operation group (SO), myocardial ischemia and reperfusion group (IR), IR + carvedilol group (CV), IR + metoprolol group (MT), and IR + propranolol group (PP). The left anterior descending branch was ligated for 30 minutes and reperfused for 4 hours (IR). After 4 h reperfusion, the distribution and composition of gap junctional connexin 43 (CX43) were observed by immunofluorescence and laser scanning confocal microscopy (LSCM), and the quantification of CX43 was measured by LSCM.</p><p><b>RESULT</b>Compared with SO group, IR resulted in abnormal distribution and composition of CX43-GJ and the impairment of CX43-GJ was significantly attenuated by CV, MT and PP treatments with the best effect observed in CV group (P<0.05 vs. MT and PP).</p><p><b>CONCLUSION</b>These results suggest that beta-blockers, especially, carvedilol, could significantly attenuate IR induced CX43-GJ impairment.</p>