Selective effects of alfuzosin and doxazosin with intraduodenal administration on urethral pressure of cats.
OBJECTIVE
To observe the selective effects of alfuzosin (Alf) and doxazosin (Dox) on the urethral pressure by different administration routes.


METHODS
The urethral pressure of the anesthetized cat was increased by electric stimulation of the hypogastric nerve. The different effects of Alf or Dox on the arterial blood pressure and urethral pressure between intraduodenal administration (i.d.) and intravenous infusion (i.v.) were compared.


RESULTS
When the hypogastric nerve was stimulated by electric stimulation (10 Hz, 25 V), the ratios of ED20(BP)/ED50(UP) i.d. to ED20(BP)/ED50(UP) i.v. were 10.9:4.3 for Alf, and 3.1:2.1 for Dox. The reduction in urethral pressure induced by i.d. Alf was greater than that by i.v. Alf. Dox did not show any difference in its effects by 2 administration routes.


CONCLUSIONS
Intraduodenal administration of Alf, but not Dox, selectively decreased the urethral pressure elevated by electric stimulation. The uroselectivity of i.d. Alf was not due to the species difference in its bioavailability and biotransformation.
Yang
Z H
ZH
Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.
Ren
L M
LM
Wu
Z J
ZJ
Fu
S X
SX
Li
Y S
YS
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D017292:Doxazosin / Q000494:pharmacology*; D004558:Electric Stimulation; D007001:Hypogastric Plexus / Q000502:physiology; D007262:Infusions, Intravenous; D008297:Male; D011312:Pressure; D011799:Quinazolines / Q000494:pharmacology*; D014521:Urethra / Q000502:physiology*
D000317:Adrenergic alpha-Antagonists; D011799:Quinazolines; C047638:alfuzosin; D017292:Doxazosin