Table 3.

Effect of 24 h incubation with NTG and DETA NONOate (DETA NO) on response of porcine coronary arteries to 8-Br-cGMP

	Relaxation to 8-Br-cGMP
	EC50, −log (M)	Max relaxation, %
24 h incubation with:
Solvent	4.98±0.07	96.97±1.02
NTG, 10−5 M	4.72±0.05a	95.38±1.33
NTG, 10−5 M and ODQ, 10−4 M	5.09±0.06	97.13±1.77
24 h incubation with:
Solvent	4.90±0.07	97.33±0.91
DETA NO, 10−5 M	4.40±0.08a	79.18±4.20a
DETA NO, 10−5 M and ODQ, 10−4 M	4.75±0.09	97.14±2.56

Abbreviations: 8-Br-cGMP, 8-bromo-guanosine 3′5′-cyclic monophosphate; DETA NONOate, [2,2′-(hydroxynitrosohydrazono) bis(ethanamine)]; NTG, nitroglycerine; ODQ, 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one.

Relaxation of porcine coronary arteries to NTG and DETA NO were determined in vessels constricted with U46619 (10⁻⁷ to 3 × 10⁻⁷ M) to a similar the tension level. Data are expressed as means±s.e.mean, n=6–9 for each group.

^aSignificantly different from vessels incubated with solvent (P<0.05).