beta-adrenoceptor density and ligand affinity , basal adenylate cyclase activity and camp synthesis upon stimulation with forskolin , fluoride , guanine nucleotides ( gtp or guanylyl imidodiphosphate ( gppnhp ) or isoproterenol in the presence of the nucleotides were studied in membranes prepared from lungs of young ( aged 2-3 months ) and of old ( aged 24-25 months ) male wistar rats .
C0018353
gtp
C0018366
guanylyl imidodiphosphate