[The effects of various beta-blockers on myocardial gap junction structure in rat with myocardial ischemia-reperfusion injury].
OBJECTIVE
To compare the effects of carvedilol, metoprolol and propranolol on myocardial gap junction (GJ) structure in rat with myocardial ischemia and reperfusion injury.


METHODS
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.


RESULTS
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).


CONCLUSIONS
These results suggest that beta-blockers, especially, carvedilol, could significantly attenuate IR induced CX43-GJ impairment.
Fan
Shu-ying
SY
Department of Cardiology, China-Japan Friendship Hospital, Beijing 100029, China.
Ke
Yuan-nan
YN
Zeng
Yu-jie
YJ
Su
De-chun
DC
Wang
Yong
Y
Zhang
Pei
P
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D018031:Connexin 43 / Q000378:metabolism; D004195:Disease Models, Animal; D017629:Gap Junctions / Q000187:drug effects*; D008297:Male; D015428:Myocardial Reperfusion Injury; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000319:Adrenergic beta-Antagonists; D018031:Connexin 43