Nitrite and Nitrate Pharmacokinetics.

摘要

Elimination kinetics of nitrite and nitrate in the canine, ovine, and equine were determined. The elimination half-life of nitrite was found to be 30.0, 28.5 and 33.9 minutes in the canine, ovine and equine, respectively; that of nitrate was 44.68, 4.23 and 4.82 hours, respectively. Apparent specific volumes of distribution (V'd) of nitrite varied from 191.6 ml/kg in the horse and 278.0 ml/kg in the sheep to 1623.7 ml/kg in the canine. Values for V'd of nitrate did vary somewhat between species (238.5 ml/kg, 291.1 ml/kg and 209.3 ml/kg for the canine, ovine and equine, respectively), but not to the extent of the V'd of nitrite. In vitro protein binding studies in canine plasma indicate that the extent of nitrite-protein binding varied directly with concentration at 5-25 micrograms NO2(-)/ml (4.5-13.6 percent bound) but inversely with concentration at 50-100 micrograms NO2(-)/ml (9.8-8.8 percent bound). Less than 1 percent of nitrate was bound to canine plasma at equimolar concentrations (5-100 micrograms NO3(1)/ml).