Figure 1.
Inhibition curves for the displacement of [3H]-N-methylscopolamine by PAPA-TAC (6), ASA-TAC (8), biotinyl-TAC (9), and the eosine isothiocyanate conjugate of TAC (15). Specific counts are shown versus concentration of the inhibitor for rat forebrain membranes (●) and rat heart membranes (○). Inhibition of [3H]NMS binding was determined by incubating the analog and membranes with 0.5 nM [3H] NMS in phosphate-buffered saline at pH 7.2 at 37 °C for 60 min. Nonspecific binding was determined by coincubation with 1 μM atropine.