RESUMEN
AIM:To determine the effects of Tongxinluo (TXL) on connexin 43 (Cx43) remodeling and ven-tricular arrhythmia ( VA) after myocardial infarction ( MI) in rats .METHODS:Male SD rats were randomly divided into sham-operated (sham) group (n=25) and operation group (n=75).The left anterior descending (LAD) was ligated in operated group , while the rats in sham group only underwent pericardiotomy .The rats in operation group which survived for 3 d after operation were randomly assigned to TXL group and MI group .The rats in TXL group was administrated with TXL (2 g? kg-1? d-1, intragastric administration) for 4 weeks, while normal saline was applied to the rats in sham group and MI group.The levels of interleukin-1β(IL-1β) and endothelin-1 (ET-1) in the tissue from the border zone were measured by ELISA after treatment .The distribution and the mRNA and protein expression of Cx 43 were detected by immunohisto-chemical staining , RT-PCR and Western blotting , respectively .The burst pacing was used to induce ventricular arrhythmia ( VA) .RESULTS:Compared with sham group , the levels of IL-1βand ET-1 and the incidence of VA were significantly increased , while the mRNA and protein expression of Cx 43 was markedly reduced with irregular distribution in MI group (P<0.05).Compared with MI group, the levels of IL-1βand ET-1 and the incidence of VA were significantly reduced , while the expression of Cx 43 at mRNA and protein levels was markedly increased with augmented linear distribution in the myocardial cell intercalated disc in TXL group (P<0.05).CONCLUSION:TXL reduces the incidence of VA after MI via inhibiting the Cx43 remodeling .