yet does not influence
the effect of the metabolically stable adenosine derivative N-ethylcarboxamidoadenos-
ine (NECA) (16). This indicates that inhibition of adenosine transport may be respon-
sible for the observed reinforcement of adenosine-stimulated cAMP accumulation,
since adenosine uptake inhibitors have been shown to have little or no effect on
cAMP accumulation induced by NECA