Table 1.

Circulatory levels of nitrogen oxide molecules at rest and during regional NO synthase inhibition followed by exercise

		Baseline	L-NMMA	L-NMMA + exercise
Nitrate, μM	Artery	40.7  ± 4.5	41.4  ± 4.9	40.4  ± 5.8
Standard diet	Vein	41.3  ± 5.5	39.3  ± 6.4	37.3  ± 5.0
n = 5
Nitrate, μM	Artery	22.9  ± 1.2	23.6  ± 2.8	25.0  ± 3.9
Low nitrate diet	Vein	21.3  ± 1.5	23.5  ± 3.0	24.8  ± 4.4
n = 5
Nitrite, nM*	Artery	540  ± 74	569  ± 93	618  ± 86
n = 10	Vein	466  ± 79	499  ± 73	531  ± 91
HMW-SNO, nM**	Artery	45  ± 14	44  ± 8	44  ± 11
n = 10	Vein	63  ± 13	67  ± 10	57  ± 9
SNO-Hb, nM†	Artery	161  ± 42	173  ± 49	123  ± 30
n = 10	Vein	142  ± 29	115  ± 34	75  ± 33

Data = mean ± SEM. *, P < 0.05 for arterial-venous gradients during study. **, P < 0.05 for venous-arterial gradients during study. 

^† Expressed as concentration in whole blood.