Table 3

A1 agonist concentration-response parameters for stimulation of [35S]GTPγS binding in membranes derived from high and low expressing CHO-K1 cells transfected with the human adenosine A1receptor

Cell LineAgonistGTPγS Binding log EC50BasalMaximumStimulation
M fmol/μg protein -fold
CHOA1LCPA−8.06  ± 0.36 (3)0.004  ± 0.0010.009  ± 0.0012.3
NECA−7.34  ± 0.17 (3)0.005  ± 0.0010.009  ± 0.0011.8
R-PIA−7.83  ± 0.23 (3)0.005  ± 0.0010.012  ± 0.0022.4
CHOA1HCPA−8.22  ± 0.36 (3)0.049  ± 0.0090.197  ± 0.0584.0
NECA−7.87  ± 0.08 (3)0.042  ± 0.0110.178  ± 0.0254.2
R-PIA−7.66  ± 0.51 (4)0.067  ± 0.0190.277  ± 0.0474.1

Values represent means ± S.E.M. obtained from three to four separate experiments (actual number given in parentheses).