A regional difference in endothelium-dependent relaxation responses to acetylcholine in the canine venous system.
Endothelium-dependent relaxations of canine veins isolated from 15 different sites were examined. Acetylcholine (ACh, 10(-10)-10(-6) M) caused marked endothelium-dependent relaxations in the external jugular vein, superior vena cava, brachiocephalic vein, segment A (supradiaphragmatic portion) and D (infrarenal portion) of the inferior vena cava. However, only contractile responses were induced by ACh in the portal, mesenteric veins and the segment C of the inferior vena cava (between liver and renal veins) with or without endothelium. The other 7 veins showed only small endothelium-dependent relaxations (10-20%). These results indicated that the endothelium-dependent responses of canine veins to ACh are regionally different.
Furuta
T
T
Department of Pharmacology, Nagoya University School of Medicine, Japan.
Shigei
T
T
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D004285:Dogs; D004727:Endothelium / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects; D014680:Veins / Q000187:drug effects*
D000109:Acetylcholine