Barnhart J L, Witt B L
Proc Soc Exp Biol Med. 1983 Sep;173(4):506-11. doi: 10.3181/00379727-173-41678.
Uptake of iopanoic acid (IOP) and iopanoate glucuronide (IOP-G) was studied in 3-day primary cultures of rat hepatocytes isolated by the collagenase perfusion method. 125I activity of cells after incubation with 125I-IOP (10-100 microM) and 125I-IOP-G (10-100 microM) was used as a measure of uptake. At each concentration, uptake was linear for the first 45 sec. In the absence of albumin, the initial uptake velocity was directly proportional to the concentration or IOP or IOP-G and was nonsaturable up to 100 microM. The calculated uptake rate constants for IOP and for IOP-G were 0.059 and 0.048 nmole/(mg protein X min X microM), respectively. IOP uptake was not inhibited by sodium taurocholate nor by the contrast agents iodipamide, ipodate, and iopronic acid. The data indicate that the enhancement of IOP excretion by bile salts noted in vivo does not occur at the uptake step and that the hepatic uptake of both IOP and IOP-G in the absence of albumin is limited by diffusion.
采用胶原酶灌注法分离大鼠肝细胞，对其进行3天的原代培养，研究了碘番酸（IOP）和碘番酸葡糖醛酸酯（IOP-G）的摄取情况。用125I-IOP（10 - 100微摩尔）和125I-IOP-G（10 - 100微摩尔）孵育细胞后，细胞的125I活性用作摄取的指标。在每个浓度下，最初45秒内摄取呈线性。在无白蛋白的情况下，初始摄取速度与IOP或IOP-G的浓度成正比，在高达100微摩尔时不饱和。计算得出的IOP和IOP-G的摄取速率常数分别为0.059和0.048纳摩尔/（毫克蛋白质×分钟×微摩尔）。牛磺胆酸钠、造影剂碘他拉酸、碘泊酸盐和碘普罗酸均不抑制IOP摄取。数据表明，体内观察到的胆盐对IOP排泄的增强作用在摄取步骤中未出现，且在无白蛋白的情况下，肝脏对IOP和IOP-G的摄取受扩散限制。
