摘要：

Infusion of adenosine into the coronary arteries of isolated guinea pig hearts produced a dosedependent inhibition of dP/dt_max caused by bolus injections of isoproterenol (4×10^–11 moles). Threshold concentration of adenosine was 10^–7 M and maximal inhibition (90%) occurred at 10^–5 M. Coronary dilation induced by, papaverine did not influence the contractile response to catecholamines. In addition to its influence on cardiac performance, adenosine (10^–5 M) effectively inhibited the isoproterenol (10^–7 M) induced initial rise in myocardial levels of cyclic 3<img src="/content/V53KG940NG251614/xxlarge8242.gif" alt="prime" align="BASELINE" border="0">5<img src="/content/V53KG940NG251614/xxlarge8242.gif" alt="prime" align="BASELINE" border="0">-AMP, glucose-1-phosphate and glucose-6-phosphate. Adenosine also antagonized the effect of isoproterenol on adenylate cyclase activity in a crude membrane preparation from guinea pig v

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