Cardiovascular Pharmacology

Chiral selective effects of doxazosin enantiomers on blood pressure and urinary bladder pressure in anesthetized rats

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To study chiral selective effects of doxazosin enantiomers on blood pressure and urinary bladder pressure in anesthetized rats.


In anesthetized rats, the carotid blood pressure, left ventricular pressure of the heart and the urinary bladder pressure were recorded.


Administration of S-doxazosin at 0.25, 2.5, 25, and 250 nmol/kg iv produced a dose-dependent decrease in blood pressure, but its depressor effect was significantly weaker than that induced by R-doxazosin and racemic-doxazosin (rac-doxazosin), and the ED30 values (producing a 30% decrease in mean arterial pressure) of R-doxazosin, rac-doxazosin and S-doxazosinwere 15.64, 45.93, and 128.81, respectively. Rac-doxazosin and its enantiomers administered cumulatively in anesthetized rats induced a dose-dependent decrease in the left ventricular systolic pressure and ±dp/dtmax, and the potency order of the 3 agents was R-doxazosin >rac-doxazosin >S-doxazosin. Rac-doxazosin and its enantiomers decreased the vesical micturition pressure dose-dependently at 2.5, 25, and 250 nmol/kg, and the inhibitory potency among the 3 agents was not significantly different.


S-doxazosin decreases the carotid blood pressure and left ventricular pressure of the heart less than R-doxazosin and rac-doxazosin, but its effect on the vesical micturition pressure is similar to R-doxazosin and rac-doxazosin, indicating that S-doxazosin has chiral selectivity between cardiovascular system and urinary system in anesthetized rats.


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Author information

Correspondence to Lei-ming Ren.

Additional information

Project supported by the Hebei Natural Science Foundation (No C2006000802).

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About this article


  • R-doxazosin
  • S-doxazosin
  • blood pressure
  • ventricular pressure
  • urinary bladder pressure
  • rat

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