Figure 3.

Functional calcium concentration response curves of some nicotinic ligands in a FLIPR Ca²⁺ influx assay, two-step addition protocol. (A) Representative concentration response curves to the agonists nicotine, varenicline, sazetidine A, cytisine and A-85380, in the first addition. The antagonists α-conotoxin MII, α-conotoxin MII[H9A;L15A], α-conotoxin PIA, methyllycaconitine, and DHβE did not significantly increase calcium response (data not shown). Data were expressed as percentage of the maximum response to nicotine. (B) Representative concentration response curves to the agonists nicotine, varenicline, sazetidine A, cytisine and A-85380 for the inhibition of channel activation induced by the subsequent addition of 200 nM nicotine. Data were expressed as percentage of the response in the absence of inhibitor. (C) Representative concentration response curves to the antagonists α-conotoxin MII, α-conotoxin MII[H9A;L15A], α-conotoxin PIA, methyllycaconitine, and dihydro-β-erythroidine for the inhibition of channel activation induced by the subsequent addition of 200 nM nicotine. Data were expressed as percentage of the response in the absence of inhibitor.