Arteriovenous differences in NO2- kinetics in anesthetized rabbits.
Despite of the importance of plasma NO2- as an index of endothelial nitric oxide (NO) formation and a substrate for NO production, only a limited kinetic knowledge is available in vivo. To address this issue, we intravenously injected NaNO2 into anesthetized rabbits and quantified changes in arterial and venous plasma NO2- levels. Plasma NO2- levels in arterial blood (956 +/- 220 nM) were slightly, but significantly, higher than those in venous blood (889 +/- 214 nM) under control conditions. Although similar half-lives of the NO2- were observed in arterial and venous plasma, significant arteriovenous differences were observed in the volume of distribution of the central compartment (0.158 +/- 0.007 l/kg in arterial blood and 0.295 +/- 0.015 l/kg in venous blood) and the peripheral compartment (0.259 +/- 0.035 l/kg in arterial blood and 0.135 +/- 0.034 l/kg in venous blood). When NOR1 (authentic NO) was injected, increases in NO2- levels were greater in arterial plasma, and decreases in blood pressure significantly correlated with arterial NO2- levels only (r = 0.90, p < 0.01). These results indicate that changes in NO2- are larger and more easily detectable as an index of NO formation in arterial plasma.
Ishibashi
Takaharu
T
Pharmacology, School of Nursing, Kanazawa Medical University, Japan.
Nishizawa
Naoki
N
Nomura
Mihoko
M
Liu
Shasha
S
Yang
Mei
M
Miwa
Tomoko
T
Shinkawa
Ikumi
I
Yoshida
Junko
J
Kawada
Tomie
T
Nishio
Matomo
M
D000758:Anesthesia; D000818:Animals; D001158:Arteries; D007700:Kinetics; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009574:Nitro Compounds / Q000494:pharmacology; D011817:Rabbits; D012977:Sodium Nitrite / Q000097:blood*; D014680:Veins
D020030:Nitric Oxide Donors; D009574:Nitro Compounds; C101316:methyl-2-hydroxyimino-5-nitro-6-methoxy-3-hexeneamide; D009569:Nitric Oxide; D012977:Sodium Nitrite