TABLE 1

Comparisons of experimental functional pK_b values with binding affinity pK_i values for selective αAR antagonists for mouse α₂AR subtypes

pK_b values represent the negative logarithm₁₀ of the K_b and are expressed as the mean. Schild regression slopes are expressed as the mean slope ± S.E. and were determined in three to five separate experiments using brain slices from WT mice. Reported pK_i values are from binding affinity studies using recombinant mouse α₂AR clones expressed in COS-7 cells. pK_b value was calculated using a single 10 μM concentration of JP-1302.

Antagonist	pK_b	Slope	Reported pK_i Values
Antagonist	pK_b	Slope				α_2AAR	α_2BAR	α_2CAR
Atipamezole	8.79	1.06 ± 0.12	9.07^a	8.30^b	8.80^a
Rauwolscine	7.75	1.01 ± 0.07	7.27^a	8.14^b	9.10^a
WB-4101	6.87	0.89 ± 0.08	6.58^a	7.15^b	8.11^a
Prazosin	5.71	0.97 ± 0.06	5.67^a	7.23^b	7.01^a

↵ a Link et al. (1992).
↵ b Chruscinski et al. (1992).