TABLE 1

Dissociation constants for recombinant A2BARs determined in radioligand binding assays

Ki values were obtained from competition binding experiments using [3H]MRS 1754. All values are the mean ± S.E. of three to four assays.

R1
R2
R3
Rat*
Human*
Dog
Rabbit
Mouse
Ratio**
nM
Xanthines
    Enprofylline H Propyl H 4730 ± 270 6960 ± 2730 5840 ± 810 5630 ± 730 1.5 (D/H)
    Theophylline Methyl Methyl H 15,100 ± 2700 9070 ± 1490 38,700 ± 6500 17,700 ± 5000 6410 ± 1300 6.0 (D/M)
    8-PT Methyl Methyl Embedded Image 415 ± 219 371 ± 99 249 ± 48 436 ± 48 1.8 (M/R)
    8-SPT Methyl Methyl Embedded Image 1330 ± 220 7240 ± 2060 2370 ± 230 4990 ± 1090 5.4 (D/H)
    DPSPX Propyl Propyl Embedded Image 721 ± 173 200 ± 11 568 ± 15 3.6 (D/R)
    XAC Propyl Propyl Embedded Image 16.0 ± 0.7 29.8 ± 9.6 4.47 ± 0.40 4.51 ± 0.44 6.7 (D/R)
    MRS 1754 Propyl Propyl Embedded Image 12.8 ± 1.1 1.97 ± 0.31 12.8 ± 1.7 1.79 ± 0.24 3.39 ± 0.18 7.2 (D,Rt/R)
    CPX Propyl Propyl Embedded Image 186 ± 5 63.8 ± 8.3 147 ± 30 96.0 ± 13.0 86.2 ± 16.0 2.9 (Rt/H)
    BG 9719 (CVT-124) Propyl Propyl Embedded Image 742 ± 76 470 ± 40 1010 ± 180 2.1 (M/R)
Non-Xanthines
    N-0861 (A1-selective) (adenine derivative) 20,070 ± 2840 17,300 ± 1760 27,500 ± 7350 1.6 (M/R)
    ZM 241385 (A2A-selective) (triazolotriazine derivative) 145 ± 15 76.2 ± 21.1 109 ± 28 31.3 ± 11.1 4.7 (H/M)
    Alloxazine (A2B-selective) (benzopteridine derivative) 2040 ± 570 2840 ± 850 648 ± 82 485 ± 35 5.9 (D/M)
    MRS 1523 (A3-selective) (pyridine derivative) 0%*** 0%*** 22 ± 3%*** 0%***
    CGS-15943 (quinazoline derivative)
32.4 ± 1.0
19.1 ± 4.1
24.4 ± 8.0
9.07 ± 1.31
3.6 (H/M)

  • ↵* Data from Kim et al. (2000, 2002) and Ji et al. (2001).

  • ↵** Ratio of species with highest Ki/species with lowest Ki (Rt, H, D, R, and M denote rat, human, dog, rabbit, and mouse, respectively).Embedded Image Embedded Image Embedded Image Embedded Image Embedded Image Embedded Image