Absence of the effect of ephedrine on levels of cyclic adenosine monophosphate in human lymphocytes.

Concentrations of 10(-6) to 10(-3) M ephedrine did not increase cyclic adenosine monophosphate (cAMP) levels of normal human lymphocytes even in the presence of theophylline or cortisol, which enhance the response to isoproterenol or prostaglandin E1. Preincubation for 2 hr with ephedrine did not reduce the subsequent effect of isoproterenol, although preincubation with isoproterenol itself did. Therefore, ephedrine is not a direct beta-adrenergic agonist on human peripheral blood lymphocytes.