title: Comparison of the direct effects of halothane and isoflurane on large and small coronary arteries isolated from dogs.
abstract: Relaxant responses to halothane and isoflurane were compared in helical strips of dog epicardial coronary arteries of different sizes: proximal large coronary arteries with outside diameters (OD) larger than 2.5 mm and distal small arteries with 0.7-0.9 mm OD. Responses to pharmacologic vasodilators, including nitroglycerin (NTG) and adenosine, were also studied for comparison. The relaxation induced by halothane in concentrations of 0.8-2.3% and by NTG (10(-9)-10(-5) M) was greater in proximal large coronary arteries than in distal small ones contracted with 20 mM KCl. In contrast, the relaxation by isoflurane (1.2-3.5%) and by adenosine (10(-8)-10(-4) M) was greater in small coronary arteries than in large ones. These results suggest that isoflurane is, like adenosine, preferentially a small artery dilator.
authors.affiliation: Department of Anesthesia, Kyoto University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hatano
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Yakushiji
authors.forename: M
authors.initials: M
authors.lastname: Nishiwada
authors.forename: K
authors.initials: K
authors.lastname: Mori
authors.forename: F C
authors.initials: FC
authors.lastname: Anaes
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D005260:Female; D006221:Halothane / Q000494:pharmacology*; D066298:In Vitro Techniques; D007530:Isoflurane / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D005996:Nitroglycerin / Q000494:pharmacology
chemical_list: D007530:Isoflurane; D005996:Nitroglycerin; D000241:Adenosine; D006221:Halothane