Testosterone does not shorten action potential duration in Langendorff-perfused rabbit ventricles

Akira Ueoka, Yen Ling Sung, Xiao Liu, Carine Rosenberg, Zhenhui Chen, Thomas H. Everett, Michael Rubart, James E. Tisdale, Peng Sheng Chen

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Background: Women have longer baseline QT intervals than men. Because previous studies showed that testosterone and 5α-dihydrotestosterone shorten the ventricular action potential duration (APD) in animal models, differential testosterone concentrations may account for the sex differences in QT interval. Objective: The purpose of this study was to test the hypothesis that testosterone shortens the APD in Langendorff-perfused rabbit ventricles. Methods: We performed optical mapping studies in hearts with or without testosterone administration. Acute studies included 26 hearts using 2 different protocols, including 17 without and 9 with atrioventricular (AV) block. For chronic studies, we implanted testosterone pellets subcutaneously in 7 female rabbits for 2–3 weeks before optical mapping studies during complete AV block. Six rabbits without pellet implantation served as controls. Results: The hearts in the acute studies were paced with a pacing cycle length (PCL) of 200–300 ms and mapped at baseline and after administration of 1 nM, 10 nM, 100 nM, and 3 μM of testosterone. There was no shortening of APD80 at any PCL. Instead, a lengthening of APD80 was noted at higher concentrations. There were no sex differences in testosterone responses. In chronic studies, heart rates were 136 ± 5 bpm before and 148 ± 9 bpm after (P = .10) while QTc intervals were 314 ± 9 ms before and 317 ± 99 ms after (P = .69) testosterone pellet implantation, respectively. Overall, ventricular APD80 in the pellet group was longer than in the control group at 300- to 700-ms PCL. Conclusion: Testosterone does not shorten ventricular repolarization in rabbit hearts.

Original languageEnglish
Pages (from-to)1864-1871
Number of pages8
JournalHeart Rhythm
Issue number11
Publication statusPublished - Nov 2022
Externally publishedYes


  • Androgen
  • Dihydrotestosterone
  • Optical mapping
  • QT interval
  • Sex differences
  • Testosterone

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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