Experimental lung research
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Adenosine (AD) has been reported to induce both pulmonary arterial constriction and dilation. We investigated the effect of AD using two complementary techniques. The isolated rat lung perfused with Earle's balanced salt solution containing albumin was used to measure pulmonary arterial (Ppa), venous, and double occlusion (microvascular; Pmv) pressure, and resistance changes. ⋯ In vessels without endothelium, only relaxation was observed. Isolated guinea pig arterial rings responded to AD with vasodilation similar to the results in the rat arterial rings. Results of this study show that AD primarily causes a direct dose-dependent relaxation of pulmonary arterial smooth muscle in both the isolated perfused lung and isolated arterial ring preparation.