Acetylcholine induced endothelial-dependent vasodilation increases as artery diameter decreases in the rabbit ear.
Isolated resistance vessels in the rabbit ear preconstricted with histamine were relaxed by acetylcholine by a proportionately greater amount than the central ear artery. The relaxation was antagonized by atropine and also by endothelium removal. Our studies represent the first direct evidence that endothelium-dependent dilation can occur in resistance vessels.
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001158:Arteries / Q000033:anatomy & histology / Q000187:drug effects*; D004423:Ear / Q000098:blood supply; D004727:Endothelium / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011817:Rabbits; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
D000109:Acetylcholine