Fig. 9.

Effect of P2Y₁R activation on A₁R agonist-mediated G protein coupling. Dose–response curves of CHA-stimulated [³⁵S]GTPγS binding were obtained incubating control HC (▪) and MeSADP-treated (100 nm) HC (•) with different agonist concentration (0.1 nm−10 µm). Data are expressed as percentage of [³⁵S]GTPγS specific binding over basal value, set to 100%, and are reported as mean ± SEM (n = 4), all performed in duplicate. Student's t-test, two-tails, unpaired: P = 0.004 for EC₅₀ of Control HC vs. MeSADP-treated HC. Aliquots of HC were also pre-exposed to the selective A₁R antagonist DPCPX (50 nm; ▴) and then stimulated by CHA (0.1 nm−10 µm).