T. Ishibashi et al., Negative NO3 center dot difference in human coronary circulation with severe atherosclerotic stenosis, LIFE SCI, 66(2), 2000, pp. 173-184
To examine whether or not the levels of NOx (nitrite; NO3- and nitrate; NO,
) in coronary circulating blood reflect endothelial dysfunction due to coro
nary atherosclerosis, NOx levels in plasma obtained from ostium of:left cor
onary artery and coronary sinus of patients who complained of chest pain we
re evaluated in relation to their coronary angiographic findings. Prior to
the study, a HPLC-Griess system for NOx measurement Was critically evaluate
d. This system has a detection limit of 0.1 mu M of NO; and NO, by 10 yl of
loading and was able to distinguish a difference of 0.1-0.2 mu M of these
substances. Heparin (1U/10 mu l) did not affect the detective and discrimin
ative abilities. NO,' difference, calculated from sino-arterial difference
of NO,, was almost zero (-0.2 +/- 0.2 mu M) in patients with either normal
coronary arteries or mild organic coronary stenosis (less than or equal to
20% narrowing), while a significant negative value(-5.9 +/- 1.7 mu M) was o
btained from patients with significant stenosis (greater than or equal to 7
0% narrowing) in the left coronary arteries. These results demonstrate reli
able ability on the HPLC-Griess system in evaluating NO2- and NO, in biolog
ical samples, and that the negative NO, difference through coronary circula
tion may reflect endothelial dysfunction in the patients with coronary athe
rosclerosis with severe organic stenosis.