摘要
Objective: To study the distribution of I_ Ca,L in endomyocardium(Endo), mid-myocardium(Mid) and epicardium(Epi) in female and male rabbit ventricle and to elucidate the mechanism of sex difference in drug-associated torsade de pointes. Methods: Whole-cell patch clamp technique was used to record action potential and I_Ca,L. Results: Action potential duration ofMidinfemale rabbit heart waslonger thanthat in male and transmural dispersion of repolarization in female was largerthan thatinmale. The densities of I_ Ca,L in Endo, Mid and Epi of female rabbits were (7.1±0.6), (10.4±0.9) and (9.6±1.1) pA/pF and they were (9.1±0.9), (10.5±1.0) and (9.8±0.9) pA/pF in male respectively. Transmural heterogeneity of I_ Ca,L in female ventricle was more significant than that in male rabbit.Conclusion:Female rabbitspossessmoresignificant transmural heterogeneityof I_Ca,L,whichmaybe responsiblefor largertransmuraldispersion of repolarization and more drug-associated torsade de pointes in female.
Objective: To study the distribution of I_ Ca,L in endomyocardium(Endo), mid-myocardium(Mid) and epicardium(Epi) in female and male rabbit ventricle and to elucidate the mechanism of sex difference in drug-associated torsade de pointes. Methods: Whole-cell patch clamp technique was used to record action potential and I_Ca,L. Results: Action potential duration ofMidinfemale rabbit heart waslonger thanthat in male and transmural dispersion of repolarization in female was largerthan thatinmale. The densities of I_ Ca,L in Endo, Mid and Epi of female rabbits were (7.1±0.6), (10.4±0.9) and (9.6±1.1) pA/pF and they were (9.1±0.9), (10.5±1.0) and (9.8±0.9) pA/pF in male respectively. Transmural heterogeneity of I_ Ca,L in female ventricle was more significant than that in male rabbit.Conclusion:Female rabbitspossessmoresignificant transmural heterogeneityof I_Ca,L,whichmaybe responsiblefor largertransmuraldispersion of repolarization and more drug-associated torsade de pointes in female.
