The inability of the rat aorta to relax to acetylcholine does not imply lack of a functional endothelium only.
1. The inability of blood vessels to relax to acetylcholine is often used as the sole test of endothelial removal. 2. Following blotting of the intimal surface of the rat aorta with filter paper, the tissue did not relax to acetylcholine and the contractions to alpha 2-adrenoceptor agonists and to the lower concentrations of noradrenaline, adrenaline, phenylephrine and KCl were enhanced. 3. However the responses to the higher concentrations of noradrenaline, adrenaline, phenylephrine and KCl were reduced. 4. These results show that blotting with filter paper destroys the endothelium and some smooth muscle.
Doggrell
S A
SA
Department of Pharmacology, School of Medicine, University of Auckland, New Zealand.
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000502:physiology; D001381:Azepines / Q000494:pharmacology; D015259:Dopamine Agents / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D004837:Epinephrine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D001381:Azepines; D015259:Dopamine Agents; D010656:Phenylephrine; D011189:Potassium Chloride; C024763:talipexole; D000109:Acetylcholine; D009638:Norepinephrine; D004837:Epinephrine