Table 1

Maximal inhibition of isoproterenol-stimulated adenylate cyclase activity by D2S and serine mutant receptors

graphic
AgonistMaximal inhibition of adenylate cyclase
D2SS193AS194AS197A
%
Dopamine81  ± 1178  ± 3094  ± 3
NPA98  ± 195  ± 398  ± 299  ± 1
DHX79  ± 30093  ± 7
Quinpirole98  ± 295  ± 396  ± 295  ± 3
7-OH-DPAT92  ± 391  ± 598  ± 192  ± 7
   

Maximal inhibition of isoproterenol-stimulated conversion of [3H]ATP to [3H]cAMP in intact C6 cells, expressed as a percentage of isoproterenol-stimulated activity in the absence of dopamine receptor agonist, was determined by analysis of dose-response curves for the indicated agonists from at least three independent experiments.