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. Author manuscript; available in PMC: 2015 Mar 18.
Published in final edited form as: Biochem Biophys Res Commun. 1986 May 14;136(3):1097–1102. doi: 10.1016/0006-291x(86)90446-8

Table 1.

Potency of adenosine analogues at a coronary A2-adenosine receptor and at a brain A1-receptor

Analogue A2 Receptor
 A1 Receptor EC50(A2)
MPRa
Relative
to Ado		 Estimated
Potencyb
EC50(nM)		 Ki(nM)c Ki(A1)
1 NECA 150 8 5.1 1.6
2 2-chloroadenosine 27 44 6.7 6.6
3N6-methyladenosine 0.05 24,000 60 400
4 R-PIA 4.3 280 1.2 230
5 CHA 1.6 750 0.85 880
6 N6-phenyladenosine 1.4 860 3.3 260
7 N6-p-tolyladenosine 1.35 890 2.5 360
graphic file with name nihms-666648-t0001.jpg [27% @ 21μM]d 210 -
9 NHCH3 4.9±1.3 240 16 15
graphic file with name nihms-666648-t0002.jpg 2.1±1.3 570 1.7 340
graphic file with name nihms-666648-t0003.jpg 3.0±0.7 400 18 22
graphic file with name nihms-666648-t0004.jpg 4.4±0.4 270 13 21
13 OCH3 3.2±1.6 380 2.5 150
14 NHCH3 7.2±1.3 170 6.7 25
15 NHNH2 3.5±0.8 340 4.5 80
16 NH(CH2)2NH2 7.8±2.5 150 0.85 180
graphic file with name nihms-666648-t0005.jpg 2.8±0.1 430 4.5 96
18 NH(CH2)2NH-CO–biotin 3.0±0.2 400 11.4 35
19 NH(CH2)2NHCO(CH2)5NH-CO–biotin 10.2±7.3 120 18 6.7
a

Molar potency ratio relative to adenosine, which is set equal to 1.0.

b

Estimated IC50 values based on potency of adenosine (MPR = 1.0) of 1,200±150 nM (6) .

c

Ki values for antagonism of binding of 1nM [3H]N6-cyclohexyladenosine to rat cerebral cortical membranes (data from 3, 4, 12).

d

Highest concentration of analogue did not raise coronary blood flow to a level × 50% of maximum possible increase. In such a case we report % increase in flow over control at the plasma nucleoside concentration achieved during infusion.