Molecular size dependence of peritoneal transport.
Molecular size dependence of peritoneal transport.
复制标题
腹膜运输的分子大小依赖性。
DOI：
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
L. Henderson
中科院分区：
文献类型：
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作者：
J. Leypoldt;H. R. Parker;R. Frigon;L. Henderson
通过使用中性葡聚糖（具有不同分子量但化学成分均一的聚合物）确定腹膜溶质转运速率与分子大小的函数关系，研究了血液和腹膜透析液之间屏障的性质。在清醒兔子腹膜透析过程中，使用连续的等渗和高渗透析溶液测量肌酐、p-氨基马尿酸 (PAH) 和中性右旋糖酐（3,000 至 50,000 道尔顿）的转运率。腹膜的渗透面积积（PA）是根据等渗交换期间透析液浓度对时间的依赖性来确定的。 PA 对分子大小的依赖性表明，当考虑较大尺寸的分子时，腹膜没有额外的阻碍。通过考虑高渗交换过程中的对流溶质传输，同时确定了溶质反射系数 (sigma) 和 PA。肌酐和 PAH 的 PA 值与等渗交换期间测定的值相似，肌酐和 PAH 的 sigma 值分别为 0.18 +/- 0.20 和 0.14 +/- 0.14。右旋糖酐 sigma 值（3,000 至 22,000 道尔顿）接近一致（0.9 至 1.0）并且相对独立于分子大小，表明该大小范围对对流传输存在重大阻碍。这项工作表明，“开放”扩散但“紧密”对流腹膜屏障的矛盾运输特性主要反映了该生物组织的独特结构特性，并且与测试溶质异质性无关。
The nature of the barrier between blood and peritoneal dialysate was studied by determining peritoneal solute transport rates as a function of molecular size using neutral dextrans, polymers with different molecular weights but uniform chemical composition. Transport rates for creatinine, p-aminohippurate (PAH), and neutral dextran (3,000 to 50,000 daltons) were measured during peritoneal dialysis in the awake rabbit using sequential isotonic and hypertonic dialysis solutions. The permeability-area product (PA) for the peritoneum was determined from the dependence of the dialysate concentration on time during the isotonic exchange. The dependence of PA on molecular size showed no additional hindrance by the peritoneum as molecules of larger size were considered. By accounting for convective solute transport during the hypertonic exchange, the solute reflection coefficient (sigma) and PA were simultaneously determined. The values of PA for creatinine and PAH were similar to those determined during the isotonic exchange, and sigma values for creatinine and PAH were 0.18 +/- 0.20 and 0.14 +/- 0.14, respectively. Dextran sigma values (3,000 to 22,000 daltons) were near unity (0.9 to 1.0) and relatively independent of molecular size, suggesting substantial hindrance to convective transport for this size range. This work demonstrates that the paradoxical transport properties of an "open" diffusive yet "tight" convective peritoneal barrier are primarily reflective of the unique structural properties of this biologic tissue and are not related to test solute heterogeneity.