Stimulation of cyclic AMP accumulation by 2 chloroadenosine: lack of incorporation of nucleoside into cyclic nucleotides

Cultured cells that respond to adenosine and 2 chloroadenosine with stimulation of accumulation of cyclic AMP were incubated with ³H 2 chloroadenosine. Cyclic AMP synthesis was stimulated with isoproterenol or 2 chloroadenosine, and the possible incorporation of ³H into cyclic AMP or 2 chloro cyclic AMP was evaluated. Such incorporation was not found to be significant. There is thus no evidence that 2 chloroadenosine and related nucleosides stimulate cyclic AMP synthesis by increasing the availability of substrate for adenylate cyclase.