Sources of human plasma cyclic AMP. Examinations before and after beta 2 adrenergic stimulation.

Plasma cyclic AMP was measured in different vessels in seventeen volunteers before and after stimulation with terbutaline. Differences between arterial blood and blood from the hepatic vein, right ventricle, inferior vena cava and a cubital vein could not be demonstrated. Only in the renal vein was the concentration of cyclic AMP decreased. Our results indicate that cyclic AMP is not generated from any specific isolated organ and that changes in cyclic AMP after subcutaneous injection of terbutaline reflect a general influence of this drug.