Pharmacological features of vascular responses of isolated rat common carotid arteries to vasroactive substances revealed by the cannula insering method.

Publisher Website
Google Scholar
Abstract
Using the cannula inserting method, we studied vascular responses of isolated rat common carotid arteries to 15 vasoactive substances. Intraluminal injections of phenylephrine, norepinephrine (NE), angiotensin II, 5-hydroxytryptamine (5-HT) and prostaglandin F2a (PGF2a) induced a strong vasoconstriction in such a way that a maximum increase in perfusion pressure amounted to approximately 50 mmHg. The order of their potencies were as follows : Phenylephrine .gtoreq. NE .gtoreq. angiotensin II > PGF2a .gtoreq.5-HT .mchgt. KCl. The selective alpha-2 agonists, xylazine and clonidine, induced no or a slight vasoconstriction. Tyramine, ATP and acetaldehyde induced only a slight constriction. Histamine, adenosine and acetylcholine (ACh) induced no effect. In preparations preconstricted by a high dose of NE, ACh and isoproterenol induced a vasodilation in a dose-related manner. It is concluded that the cannula inserting method is useful for investigating vascular responses in isolated and perfused rat vessels.