Notes: SQ 22,536 is an inhibitor of adenylyl cyclase with an IC50 value of 13 μM for inhibition of prostaglandin E1-stimulated increase in cAMP in intact platelets.{20863} It has been used to evaluate adenylyl cyclase activity during iloprost-induced vasorelaxation of isolated pulmonary veins or aorta in several research paradigms, inhibiting cAMP elevation at concentrations of 100-300 μM without effecting relaxation.{20861,20862}