[Effects of doxepin on isolated basilar and saphenous artery rings of rabbits].
OBJECTIVE
To study the effects of doxepin (Dox) on cerebral artery.


METHODS
The effects of Dox were observed using the isolated basilar and saphenous artery rings of rabbits.


RESULTS
Dox inhibited the constriction of the basilar and saphenous artery rings evoked by KCl with IC50 5.75 mumol.L-1 (95% confidence limits were 2.3-14 mumol.L-1, n = 8) and 34.6 mumol.L-1 (95% confidence limits were 3.8-316 mumol.L-1, n = 8), respectively. Dox also inhibited the constriction of the basilar and saphenous artery rings of the rabbits stimulated by 5-hydroxytryptamine (5-HT), IC50 were 6.3 mumol.L-1 (95% confidence limits were 1.7-23.3 mumol.L-1, n = 7) and 8.0 mumol.L-1 (95% confidence limits were 6.3-10.3 mumol.L-1, n = 6), respectively. In both samples (basilar and saphenous artery rings) CaCl2 evoked, the pD2 of Dox was 5.28 +/- 0.40 and 4.76 +/- 0.14, respectively (n = 6, P < 0.01). Dox 5.8 mumol.L-1 inhibited the constriction of the saphenous artery evoked by norepinephrine (NE) in Ca(2+)-free medium. Dox 30 mumol.L-1 inhibited the constriction of the saphenous artery evoked both by NE and by readmission of CaCl2 (1.25 mmol.L-1).


CONCLUSIONS
As compared with its effect on the saphenous artery, Dox selectively inhibited the basilar artery.
Qi
M
M
Department of Pharmacology, He-nan Medical University, Zhengzhou, China.
Hu
X J
XJ
Lü
A G
AG
Ke
J
J
Zhang
G Q
GQ
D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology*; D001488:Basilar Artery / Q000187:drug effects*; D004316:Doxepin / Q000494:pharmacology*; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000037:antagonists & inhibitors; D011817:Rabbits; D012702:Serotonin Antagonists / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*
D000929:Antidepressive Agents, Tricyclic; D012702:Serotonin Antagonists; D004316:Doxepin; D009638:Norepinephrine