Table 1.

Assessment of the potential for cCMP, cUMP, cIMP, and cTMP to contaminate cAMP enzyme immunoassays

	Normalized cAMP Reading
cNMP Added, pmol	4 pmol cAMP	150 pmol cAMP
0 cNMP	1.00 ± 0.00	1.00 ± 0.00
15 cGMP	1.37 ± 0.49	1.05 ± 0.08
150 cGMP	1.48 ± 0.02	1.06 ± 0.08
1,500 cGMP	4.3 ± 0.1	1.23 ± 0.14
15,000 cGMP	9.6 ± 0.3	1.71 ± 0.26
15 cCMP	0.88 ± 0.07	1.10 ± 0.10
150 cCMP	0.73 ± 0.19	1.04 ± 0.12
1,500 cCMP	1.70 ± 0.28	1.08 ± 0.11
15,000 cCMP	5.3 ± 0.4	1.36 ± 0.15
15 cUMP	0.99 ± 0.14	1.39 ± 0.31
150 cUMP	1.21 ± 0.30	0.95 ± 0.07
1,500 cUMP	3.6 ± 2.4	0.97 ± 0.04
15,000 cUMP	11.7 ± 8.6	1.18 ± 0.17

Data were normalized to readings for cAMP alone and are presented as means ± SE, performed in triplicate. Indicated amounts of cNMP were added to known amounts of cAMP (4 or 150 pmol cAMP as indicated). Apparent cAMP levels were measured using cAMP enzyme immunoassays.