Possible Interaction: Hydroxocobalamin and Nitric Oxide

“Again, trapping NO with HCB blocked HO-2 inactivation.”

“In addition to binding cyanide, hydroxocobalamin binds vasodilatory compounds hydrogen sulfide and carbon monoxide and affects nitric oxide metabolism, potentially explaining observed hypertension.”

“The NO0 scavenger hydroxocobalamin blunted NO release.”

“Hemoglobin, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazolinel-oxyl-3-oxide, and hydroxo-cobalamin inhibited the relaxation to NO , but not to EFS and nitroglycerin in the presence of DETCA.”

“The NO· scavengers, carboxy‐PTIO, (2‐(4‐carboxyphenyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide; 100 μM) and hydroxocobalamin (100 μM), both inhibited responses to NO gas solution and to the three NO donor drugs, but not Angeli's salt.”

“ Hydroxocobalamin (10−4 M) inhibited relaxations to NO by 50%, but not the electrically induced responses.”

“In endothelium-denuded guinea-… basilar artery preparations, hydroxocobalamin (30, 100 and 300 microM) concentration-dependently … the vasodilator responses to exogenous nitric oxide ( NO ), whereas the vasodilator responses to nitrergic nerve stimulation were slightly reduced by high (… and 300 microM) but not by the low (30 microM) concentration of hydroxocobalamin.”

“6 Hydroxocobalamin (5–1000 μm) inhibited, equally, relaxations to both NO (‐logIC40 3.14 ± 0.33) and nitrergic stimulation (‐logIC40 3.17 ± 0.22).”

“1 In organ bath experiments, hydroquinone (30–100 μm) and hydroxocobalamin (30–100 μm) concentration‐dependently inhibited the relaxations induced by NO (0.3–30 μm) but not those by nitroglycerin (GTN, 1 μm) in the canine ileocolonic junction (ICJ).”

“The cobalt atom of hydroxocobalamin (OHC) binds cyanide and nitric oxide (NO) and OHC attenuates vascular responses to NO in vitro.”