Fig. 4.

NO metabolites formed during the slow mode reaction in native plasma. A: 30-min incubation of 100 μM NO in native plasma produced nitrite concentrations in the four study groups ranging from 13 ± 3 μM (human adult) to 19 ± 5 μM (human fetus), with no significant differences between the groups. B: SNO production ranged from 2 ± 0.4 μM (human adult) to 4 ± 0.5 μM (sheep adult) without any significant differences between adult and fetal groups. C: direct measurement of free and reversibly bound NO yielded <0.4% of injected NO remaining in plasma, a value not significantly different from zero (n = 3 except for human adult with n = 4).