Résumé
AIM:Todetecttheeffectofspironolactoneonhyperthyroxine-inducedatrialremodeling.METH-ODS:New Zealand rabbits were divided into control group ( C ) , hyperthyroxine group ( H ) and spironolactone group ( S) .Thyroxin was given to the rabbits in group H and group S by intraperitoneal injection for 4 weeks , and then spirono-lactone was given in group S by gavage for 2 weeks.Atrial fibrillation (AF) was induced by burststimulation after ad-ministration.The inducing rate of AF and atrial effective refractory period ( AERP) were tested by intra-cardiac electro-physiologic instrument.The expression of AF-related Ca2+channel (Cav1.2), K+channels (Kv1.5 and Kv4.3) and con-nexins (Cx40 and Cx43) at mRNA and protein levels was detected by real-time PCR, immunohistochemistry and Western blot.RESULTS:Spironolactone reduced the inducing rate of AF .No significant difference of AERP between group H and group S was observed (P>0.05).Compared with group H, the protein expression of Cav1.2 was significant increased in group S (P<0.05).The expression of Kv1.5 at mRNA and protein levels in group S was significantly lower than that in group H (P<0.05), while the protein expression of Kv4.3 in group S was significantly decreased compared with group H (P<0.05).The mRNA expression of Cx43 in group S was significantly decreased compared with group H (P<0.01), whereas the protein expression of Cx 40 in group H was significantly higher than that in group S ( P<0.05 ) .CONCLU-SION:Spironolactone attenuates the hyperthyroxine-induced atrial remodeling in rabbits , and reduces the susceptibility of the myocardium to AF .