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Objective: To study the distribution of ICa,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 ICa,L. Results: Action potential duration of Mid in female rabbit heart was longer than that in male and transmural dispersion of repolarization in female was larger than that in male. The densities of ICa,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 ICa,L in female ventricle was more significant than that in male rabbit. Conclusion: Female rabbits possess more significant transmural heterogeneity of ICa,L, which may be responsible for larger transmural dispersion of repolarization and more drug-associated torsade de pointes in female.