M. Gerova et al., NO CONCENTRATION IN, THE PERIENDOTHELIAL AREA OF THE FEMORAL-ARTERY OF THE DOG MEASURED IN-VIVO, Physiologia bohemoslovaca, 47(3), 1998, pp. 169-175
. NO concentration was measured in the periendothelial area of the fem
oral artery by Malinski's porphyrinic . NO sensor in seven anaesthetiz
ed dogs. The basal concentration was 154.2+/-5.6 nM and two-minute int
raarterial infusions of acetylcholine (3-4 mu g/ml/min) or bradykinin
(30-40 ng/ml/min) increased this value significantly to 204.3+/-16.4 a
nd 266.5+/-16.4 nM (P<0.01), respectively. Inhibition of . NO synthase
by L-NAME (50 mg/kg) declined the basal . NO concentration only to 13
7.2+/-3.3 nM (P<0.01). Subsequent administration of acetylcholine and
bradykinin attenuated significantly the increase in . NO concentration
. Surprisingly, both agonists still induced a significant increase of
. NO concentration by 125.3+/-8.3 and 156.6+/-26.9 nM, respectively (P
<0.01). One of the possible explanations may be that besides arginine-
citrulline plus the . NO pathway other sources of . NO could be involv
ed in the high level of . NO after . NO synthase blockade by L-NAME.