Table 1

Comparison between reported potency and selectivity of inhibitors of various kinases and their potency in inhibiting A_2B-mediated IL-8 production

Inhibitor	IC₅₀ for IL-8 Production	Reported IC₅₀	Reference
	μM	μM and selectivity
Genistein	33 ± 24	30	White and Lee, 1993
		Nonselective tyrosine kinase inhibitor
Herbimycin A	0.23 ± 0.18	0.87	White and Lee, 1993
		Nonselective tyrosine kinase inhibitor
PD 098059	3 ± 1	2–10	Dudley et al., 1995; Pang et al., 1995
		Selective MEK 1 inhibitor
Wortmannin	No inhibition	0.005	Arcaro and Wymann, 1993
		Selective PI 3-kinase inhibitor
SB 203580	0.3 ± 0.2	0.6	Cuenda et al., 1995
		Selective p38 MAPK inhibitor
SB 202190	0.3 ± 0.1	0.4	Li et al., 1996
		Selective p38 MAPK inhibitor

To determine IC₅₀ for inhibition of A_2B adenosine receptor-mediated IL-8 production, HMC-1 cells were incubated in the absence or presence of increasing concentrations of inhibitors and in the presence of 3 μM NECA for 2.5 h. Values are presented as mean ± SEM of three to four experiments.