Till A E, Benet L Z
J Pharmacol Exp Ther. 1979 Dec;211(3):555-60.
Pseudoephedrine is an organic base used in the treatment of upper respiratory tract disorders. Surgical techniques and experimental procedures were developed to study the renal elimination mechanisms for this drug in the rat. The ability to measure renal clearance accurately and to demonstrate renal secretion by a carrier-mediated transport system was verified by comparing results from N'-methylnicotinamide (NMN) excretion studies with literature results. Renal tubular secretion of NMN was shown to be saturable and was inhibited by mepiperphenidol to the same extent as that reported in the literature. Pseudoephedrine was cleared by the kidney at a rate in excess of inulin and close to or possibly greater than renal plasma flow. In addition to filtration and secretion, pseudoephedrine appeared to be subject to pH dependent passive reabsorption. When the secretion of pseudoephedrine was studied in detail, it was found to be nonsaturable for plasma levels of pseudoephedrine ranging from 0.16 to 1.5 microgram/ml. Secretion, however, was inhibited by mepiperphenidol suggesting a carrier-mediated process.
伪麻黄碱是一种有机碱，用于治疗上呼吸道疾病。已开发出手术技术和实验程序来研究大鼠体内该药物的肾脏排泄机制。通过将N'-甲基烟酰胺（NMN）排泄研究的结果与文献结果进行比较，验证了准确测量肾脏清除率以及通过载体介导的转运系统证明肾脏分泌的能力。结果表明，NMN的肾小管分泌是可饱和的，并且被美哌隆多抑制的程度与文献报道相同。伪麻黄碱在肾脏中的清除速率超过菊粉，接近或可能大于肾血浆流量。除了滤过和分泌外，伪麻黄碱似乎还会发生pH依赖性被动重吸收。当详细研究伪麻黄碱的分泌时，发现当伪麻黄碱的血浆水平在0.16至1.5微克/毫升范围内时，其分泌不饱和。然而，分泌受到美哌隆多的抑制，表明这是一个载体介导的过程。
