in the presence of 100 microm gtp , 100 microm guanyl-5'-yl imidodiphosphate [ gpp ( nh ) p ] , or 10 mm naf , there is a greater than additive increase in forskolin-stimulated enzyme activity as well as a concomitant decrease ( two- to fourfold ) in the ec50 value for forskolin stimulation of striatal enzyme activity .
C0018353
gtp
C0018366
gpp ( nh ) p