“ Adenosine and derivatives modified in the ribose function were inhibitory, irrespective of the stimulant used, both in the presence of MgCl2 or MnCl2.”
“N6-substituted adenosine analogs proved to be inhibitory in the presence of 5 MM MgCl2 , but in the presence of 1 mM MnCl2 the fluoride stimulated adenylate cyclase activity was potentiated, while basal and isoprenaline stimulated activity were not significantly inhibited.”