Waschek J A, Fielding R M, Pond S M, Rubin G M, Effeney D J, Tozer T N
J Pharmacol Exp Ther. 1985 Aug;234(2):431-4.
The effects of plasma inorganic sulfate concentrations on the dose-dependent kinetics of salicylamide (SAM) were examined in the dog. Decreasing plasma sulfate concentrations from 0.9 mM to less than 0.3 mM significantly decreased clearance of a small dose of SAM (5 mg/kg) to the sulfate conjugate. Infusing sodium sulfate to prevent the decrease in plasma inorganic sulfate concentration that follows a p.o. 20-mg/kg dose of SAM did not increase SAM elimination. However, sodium sulfate given p.o. decreased SAM bioavailability, which suggests a local effect of sulfate on intestinal first-pass metabolism of SAM. These data show some dependence of SAM metabolism on plasma inorganic sulfate concentrations, but only when they are markedly reduced.
在犬体内研究了血浆无机硫酸盐浓度对水杨酰胺（SAM）剂量依赖性动力学的影响。将血浆硫酸盐浓度从0.9 mM降至低于0.3 mM，显著降低了小剂量SAM（5 mg/kg）向硫酸盐结合物的清除率。口服20 mg/kg剂量的SAM后，输注硫酸钠以防止血浆无机硫酸盐浓度降低，并未增加SAM的消除。然而，口服硫酸钠降低了SAM的生物利用度，这表明硫酸盐对SAM的肠道首过代谢有局部作用。这些数据表明SAM代谢在一定程度上依赖于血浆无机硫酸盐浓度，但仅在其显著降低时才会如此。
