Table 1

IC₅₀ values for the inhibition of specific [¹²⁵I-Tyr³]NT binding and [³H]SR 48692 binding in various membrane preparations

Binding Assay	IC₅₀ ( nM)
Binding Assay	NT	SR 142948A	SR 48692
[¹²⁵I-Tyr³]NT binding
h-NTR1-CHO cells	0.47 ± 0.07	1.19 ± 0.15	19.3 ± 4.9
HT 29 cells	0.26 ± 0.04^1-a	0.32 ± 0.08	30.3 ± 1.5^1-a
Adult rat brain	3.20 ± 0.50^1-a	3.96 ± 1.12	82.0 ± 7.4^1-a
Adult guinea pig brain	2.80 ± 1.60^1-a	0.37 ± 0.01	0.99 ± 0.14^1-a
[³H]SR 48692 binding
Adult guinea pig brain	102 ± 13	0.30 ± 0.05	6.0 ± 1.2

Each value represents the mean ± S.E.M. from at least three separate experiments performed in triplicate.

↵1-a Results were previously reported (Gully et al., 1993) and obtained under identical conditions.