PERICARDIAL FLUID ADENOSINE IN ISCHEMIC AND VALVULAR HEART-DISEASE

Adenosine released by ischemic myocardial cells stimulates coronary ar tery vasodilation. Measurement of adenosine concentrations in pericard ial fluid in animal models of myocardial ischemia has been used to stu dy the process of adenosine release. To determine whether pericardial fluid adenosine concentrations are increased in human ischemic heart d isease, adenosine concentrations were measured in pericardial fluid in 23 subjects undergoing open-heart surgery for coronary artery disease . The results were compared with adenosine concentrations measured in pericardial fluid obtained from 20 subjects undergoing surgery for val vular heart disease. Adenosine concentrations also were measured in pl eural fluid obtained during internal mammary artery bypass grafting. A denosine concentrations were significantly increased in subjects with coronary artery disease compared with fluid obtained from subjects wit h valvular heart disease (2.47 +/- 0.24 vs 1.36 +/- 0.21 [SEM] mu M [p = 0.0013]), Adenosine concentrations were higher in pleural fluid tha n pericardial fluid from the same individuals. Adenosine concentration s were significantly correlated with pericardial fluid cell counts and lactate dehydrogenase concentrations (r = 0.48; p = 0.0012 and r = 0. 77, p = 0.0001, respectively). The results are consistent with myocard ial release of adenosine in ischemic heart disease. If adenosine conce ntrations in pericardial fluid approximate those in myocardial interst itial fluid, sufficient adenosine is present to stimulate adenosine re ceptor activation in coronary artery smooth muscle.