Summary
The current difference between male and female rabbit ventricular myocytes was investigated for elucidating the mechanism of longer QT interval and higher incidence of drug-associated torsade de pointes in female rabbits than in male rabbits. Whole cell patch clamp technique was used to record APD,I to,I k, tail,I k1 andI Ca,L of myocytes from left ventricular apex. There was no difference in the membrane capacitance between male and female rabbit myocytes. APD90 was longer in female rabbits (560.4±26.5 ms,n=15) than in male ones (489.0±20.7 ms,n=14),P<0.05. In female rabbit myocytes,I K, tail,I to,I Ca, L were 0.71±0.05 pA/pF (n=17), 8.28±1.03 pA/pF (n=18), 24.5±3.6 pA/pF (n=12) and 9.0±2.3 pA/pF (n=15) respectively. In male rabbit myocytes, they were 0.84±0.07 pA/pF (n=18), 8.60±1.20 pA/pF (n=18), 25.9 ±4.5 pA/pF (n=14) and 9.3±2.6 pA/pF (n=16) respectively.I K, tail in female rabbits was significantly lower than that of male rabbits (P<0.05), but there was no difference inI to,I Ki andI Ca, I between male rabbits and female rabbits (P>0.05). The lowerI K, tail of female rabbit myocytes may contribute to the longer repolarization and the higher incidence of drug-associated torsade de pointes.
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RUAN Yanfei, female, born in 1973, Doctor in Charge
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Yanfei, R., Nian, L., Qiang, Z. et al. Sex difference in the repolarization currents of rabbit ventricular cells. Current Medical Science 25, 260–262 (2005). https://doi.org/10.1007/BF02828136
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DOI: https://doi.org/10.1007/BF02828136