Thomas P, Toth C A, Zamcheck N
Hepatology. 1982 Nov-Dec;2(6):800-3. doi: 10.1002/hep.1840020610.
The transport of human alpha 1-acid glycoprotein from the circulation to the bile has been studied in the rat. Biliary excretion was proportional to the i.v. injected dose, and the percentage excreted remained constant. The amount excreted in the bile (over 4 hr) was inversely related to the rate of hepatic (hepatocyte) uptake and the galactose receptor which is specific for asialo glycoproteins was not involved. Reinjection of the glycoprotein excreted in bile resulted in a similar proportion of the dose being reexcreted, suggesting that a subset of the glycoprotein is not selected for excretion in bile. Transit times from blood to bile for glucagon, insulin, alpha 1-acid glycoprotein, fetuin, albumin, and carcinoembryonic antigen were directly related to their molecular weights. Removal of sialic acid from the asialo glycoproteins did not affect these transit times. Possible mechanisms for the biliary excretion of alpha 1-acid glycoprotein are discussed.
已在大鼠中研究了人α1-酸性糖蛋白从循环系统到胆汁的转运。胆汁排泄与静脉注射剂量成正比，排泄百分比保持恒定。胆汁中排泄的量（4小时内）与肝脏（肝细胞）摄取率呈负相关，且不涉及对去唾液酸糖蛋白具有特异性的半乳糖受体。重新注射胆汁中排泄的糖蛋白会导致类似比例的剂量再次排泄，这表明一部分糖蛋白未被选择排泄到胆汁中。胰高血糖素、胰岛素、α1-酸性糖蛋白、胎球蛋白、白蛋白和癌胚抗原从血液到胆汁的转运时间与它们的分子量直接相关。从去唾液酸糖蛋白中去除唾液酸并不影响这些转运时间。文中讨论了α1-酸性糖蛋白胆汁排泄的可能机制。
