Table 1

Activities of adenine nucleotides in CHO-hP2Y₁₁ and CHO-cP2Y₁₁ cells

Nucleotide	IP Accumulation		Cyclic AMP Accumulation		Ratio^1-b
Nucleotide	EC₅₀	IA^1-a	EC₅₀	IA^1-a	Ratio^1-b
Human P2Y₁₁Receptor	μM		μM	%
ATP	3.6 ± 1.3	100	62.4 ± 15.6	100	17.3
ADP	50.1 ± 20.6	60.2 ± 4.3	NM	NM	NM
ATPγS	1.2 ± 0.4	95.3 ± 4.3	23.2 ± 6.5	83.5 ± 7.0	19.3
ADPβS	3.7 ± 0.7	71.8 ± 1.1	25.9 ± 0.4	78.4 ± 5.8	7
2MeSATP	2.4 ± 0.4	99.4 ± 8.2	26.5 ± 3.7	99.4 ± 5.5	11
2MeSADP	14.6 ± 3.2	60.5 ± 6.0	NM	NM	NM
Canine P2Y₁₁ Receptor
ATP	32.8 ± 13.4	96.8 ± 9.3	76.4 ± 29.2	94.8 ± 9.3	2.3
ADP	6.1 ± 1.4	100	10.9 ± 3.7	100	1.8
ATPγS	19.3 ± 4.9	78.4 ± 3.4	74.0 ± 3.6	61.4 ± 4.0	3.8
ADPβS	0.14 ± 0.07	86.0 ± 2.4	0.40 ± 0.06	97.7 ± 6.5	2.9
2MeSATP	0.57 ± 0.11	66.2 ± 3.5	2.2 ± 0.4	74.9 ± 5.0	3.9
2MeSADP	0.08 ± 0.01	102 ± 6.8	0.16 ± 0.03	84.0 ± 2.5	2.0

Data shown are mean ± S.D. from three to six separate experiments.

↵1-a IA, intrinsic activity, normalized to the maximal response of 300 μM ATP (hP2Y₁₁) or 100 μM ADP (cP2Y₁₁).
↵1-b Ratio of the EC₅₀ for cyclic AMP accumulation to the EC₅₀ for inositol phosphate (IP) accumulation.
NM, response did not reach a maximum.