Arvidsson A, Alván G, Borgå O, Eklöf R
Br J Clin Pharmacol. 1983 Mar;15(3):339-46. doi: 10.1111/j.1365-2125.1983.tb01508.x.
Cephapirin, a beta-lactam antibiotic, was administered intravenously to five healthy subjects in a dose of 1 g. Renal clearances of cephapirin, beta 2-microglobulin, uric acid and amino acids were measured during the experiment and compared to timed control data, i.e. when no cephapirin was given. Renal clearance of cephapirin decreased when plasma concentrations declined. As protein binding of cephapirin is constant over a wide plasma concentration range, this finding may indicate that cephapirin is reabsorbed in the kidney by a saturable process. Renal clearance of endogenous amino acids, particularly those belonging to the basic group increased after cephapirin. There was no change in renal clearance of beta 2-microglobulin which excludes a general toxic effect on tubular reabsorption of endogenous substances caused by cephapirin. A flow dependent increase of uric acid clearance was observed. Our results are suggestive of a competition between cephapirin and amino acids for some common step in the tubular reabsorption process.
头孢匹林，一种β-内酰胺类抗生素，以1克的剂量静脉注射给5名健康受试者。实验期间测定了头孢匹林、β2-微球蛋白、尿酸和氨基酸的肾清除率，并与定时对照数据进行比较，即未给予头孢匹林时的数据。当血浆浓度下降时，头孢匹林的肾清除率降低。由于头孢匹林在很宽的血浆浓度范围内蛋白结合率恒定，这一发现可能表明头孢匹林在肾脏中通过一个可饱和过程被重吸收。头孢匹林给药后，内源性氨基酸的肾清除率增加，尤其是那些属于碱性组的氨基酸。β2-微球蛋白的肾清除率没有变化，这排除了头孢匹林对内源性物质肾小管重吸收产生普遍毒性作用的可能性。观察到尿酸清除率随流量增加。我们的结果提示头孢匹林和氨基酸在肾小管重吸收过程的某个共同步骤上存在竞争。
