Table 3:
Substrate Binding Affinity of Adenosine Receptors
| Receptor | Selective agonists | Selective antagonists | Radioligands | Reference | |||
|---|---|---|---|---|---|---|---|
| compound | affinity | compound | affinity | compound | affinity | ||
| A1 | Adenosine | 70nM-0.31μM (EC50) | DPCPX | 0.3–3.9nM | [3H]-CCPA | 0.6 (Kd) | (J. F. Chen, et al., 2014; Fredholm, et al., 2007; Geiger, LaBella, & Nagy, 1984; Klotz, 2000; Klotz, Keil, Zimmer, & Schwabe, 1990; Kreft, Bier, Holschbach, Schulze, & Coenen, 2017; Martin, Wysocki, Barrett, May, & Linden, 1996; Stockwell, Jakova, & Cayabyab, 2017; Yun, et al., 2019) |
| CPA | 8.9 (pKi) | 8-cyclopentyltheophylline | 7.5–8.0pM (Ki) | [3H]-R-PIA | 2.0 (Kd) | ||
| CCPA | 800 (pKi) | WRC0571 | 8.8pM (Ki) | [3H]-CHA | - | ||
| CHA | 3.6 | - | - | [3H] NECA | 14 (Kd) | ||
| S-ENBA | 0.3nM | - | - | 125I-AB-MECA | 3.4–8.5 | ||
| LUF6944 | 7.6 (Ki) | - | - | [3H]-DPCPX | 0.3–3.9 (Kd) | ||
| LUF6941 | 7.9 (Ki) | - | - | CPMMCB | 3.73nM (Ki) | ||
| - | - | - | - | CPFPX | 3.49nM (Ki) | ||
| - | - | - | - | CBCPM | 8.68nM (Ki) | ||
| A2A | Adenosine | 0.7μM (EC50) | Caffeine | 43,000nM (Ki) | [3H]-CGS 21680 | 32nM (Kd) | (de Lera Ruiz, et al., 2014; Dionisotti, et al., 1997; Fernandez-Duenas, et al., 2014; Fredholm, 2007; Fredholm, et al., 2001; Grahner, Winiwarter, Lanzner, & Muller, 1994; Klotz, et al., 1998; C. E. Muller, et al., 1998; Murphree, Marshall, Rieger, MacDonald, & Linden, 2002; Nonaka, Ichimura, et al., 1994; Nonaka, Mori, et al., 1994; O’Malley, et al., 2009; Okusa, Linden, Macdonald, & Huang, 1999; Olah, Jacobson, & Stiles, 1994; Palmer, Poucher, Jacobson, & Stiles, 1995; Preti, Baraldi, Moorman, Borea, & Varani, 2015; van der Walt & Terre’Blanche, 2018) |
| C2-/C8-substituted adenosine | 7.19nM (Ki) | SCH 58261 | 0.6 nM (Ki) | [3H]-NECA, 125 | 20nM (Kd) | ||
| 2-((4-aryl(alkyl)piperazin-1-yl)alkylamino)-5′-N-ethylcarboxamidoadenosine (2-F, 4-Cl) | 4.78nM (Ki) | ZM241385 | 1.4 nM (Ki) | I-ZM 241385 | 0.7nM (Kd) | ||
| CGS 21680 | 72±10nM (Kd) | KF 17387, CSC | 1± 0.057nM (Ki) | [3H]-MSX-2 | 8nM (Kd) | ||
| HE-NECA | 36±2nM (Kd) | 5-hydroxy-2-(3-hydroxyphenyl)-4H-1-benzopyran-4-one | 1.44uM (Ki) | 125I-AB-MECA | 25nM (Kd) | ||
| CV-1808 | 76 nM (Ki) | Istradefylline | 36nM (Ki) | [3H]-SCH 58261 | 2nM (Kd) | ||
| CV-1674 | - | - | - | - | - | ||
| ATL146e | 0.2nM (Ki) | - | - | [3H]-ZM-241385 | - | ||
| A2B | Adenosine | 24μM (EC50) | MRS1754 (enprofylline) | 2nM (Ki) | [3H]-DPCPX) | 56 nM (Ki) | (Fredholm, 2007; Fredholm, et al., 2001; Jacobson & Gao, 2006; Linden, Thai, Figler, Jin, & Robeva, 1999; Preti, et al., 2015) |
| LUF5835 | 10nM (Ki) | MRE 2029-F20 | 3nM (Ki) | 125 I-ABOPX | 36 nM (Kd) | ||
| 2-((4-aryl(alkyl)piperazin-1-yl)alkylamino-5’-Nethylcarboxamidoadenosines scaffold | 1487nM (Ki) | OSIP-339391 | 0.5nM (Ki) | [3H]-ZM-241385 | 33 nM (Kd) | ||
| A3 | Adenosine | 0.29μM (EC50) 6500nM | MRS 1220 | 0.7 0.65 |
[3H]-PIA | 16 (Kd) | (J. F. Chen, et al., 2014; Jacobson, et al., 2012; Jacobson, et al., 2018; Y. C. Kim, Ji, & Jacobson, 1996; Klotz, et al., 1998; A. H. Li, Moro, Melman, Ji, & Jacobson, 1998; Olah, et al., 1994; Stockwell, et al., 2017; van Muijlwijk-Koezen, Timmerman, Link, van der Goot, & AP, 1998; van Muijlwijk-Koezen, Timmerman, Link, van der Goot, & Ijzerman, 1998; Varani, et al., 2000) |
| 2-Cl-IB-MECA | 11 | MRE 3008-F20 | 9.54 (pKi) | [3H]-NECA | 6.2 (Kd) | ||
| CCPA | 18.8μM (Ki) 42 | MRS 1191 | 31.4 | 125I-AB-MECA | 0.6–1.5 | ||
| - | - | MRS 1523 | 18.93nM (Ki) | [3H]-MRE 3008-F20 | 0.8 (Kd) | ||
| - | - | VUF 8504 | 17nM | [3H]-MRS7799 | 0.55nM (Kd) | ||