Pharmacologic Inhomogeneity Between the Reactivity of Intramural Coronary Arteries and Arterioles

Abstract
We hypothesized that because of their size, anatomic location, and hemodynamic function, coronary arteries and arterioles would respond differently to vasoactive substances. Intramural arteries (281.7 ± 23.1 μm) and arterioles (77.3 ± 6.6 μm) of the left anterior descending coronary of rats were isolated and cannulated. Spontaneous tone was lower in arteries than in arterioles (81.1 ± 5.7 vs. 53.0 ± 3.9% of passive diameter, p −8