Tissue sites of catabolism of albumin in rabbits.
Tissue sites of catabolism of albumin in rabbits.
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兔子白蛋白分解代谢的组织位点。
DOI：
10.1152/ajpendo.1983.244.1.e101
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Steinberg,D
中科院分区：
文献类型：
--
作者：
Yedgar,S;Carew,TE;Pittman,RC;Beltz,WF;Steinberg,D
使用[14 C]蔗糖标记的兔白蛋白确定兔中白蛋白分解代谢的位点。[14 C]蔗糖部分不可降解，并在降解蛋白质的组织中积累。用[14 C]蔗糖标记白蛋白，并选择单体形式注射到家兔体内。蔗糖标记的白蛋白作为天然白蛋白示踪剂的有效性通过125 I标记的白蛋白与蔗糖衍生的白蛋白和131 I标记的天然白蛋白的相似血浆衰减动力学以及[14 C]蔗糖-白蛋白的生物筛选和未筛选制剂的相似衰减动力学来证明。注射[14 C]蔗糖-白蛋白后2天，测定组织中可溶于三氯乙酸的累积14 C标记降解产物。所有组织都分解代谢白蛋白，没有组织具有主要重要性;肝脏、肾脏和肌肉是最大的贡献者。以每单位湿重的活性表示，肾上腺、肾脏、脾脏、卵巢、骨髓和肝脏最活跃。这些最活跃的组织是那些有孔或不连续的毛细血管床，表明暴露于高浓度白蛋白是其高白蛋白降解率的重要决定因素。
The sites of albumin catabolism were determined in rabbits using [14C]sucrose-labeled rabbit albumin. The [14C]sucrose moiety is not degradable and accumulates in tissues degrading the protein. Albumin was labeled with [14C]sucrose, and the monomeric form was selected for injection into rabbits. The validity of the sucrose-labeled albumin as a tracer for native albumin was shown by the similar plasma decay kinetics of 125I-labeled albumin derivatized with sucrose and 131I-labeled native albumin and by the similar decay kinetics for the biologically screened and unscreened preparations of [14C]sucrose-albumin. Two days after injection of [14C]sucrose-albumin, tissues were assayed for accumulated 14C-labeled degradation products soluble in trichloroacetic acid. All tissues catabolized albumin with no tissue of predominant importance; liver, kidney, and muscle were the largest contributors. Expressed in terms of activity per unit wet weight, adrenal, kidney, spleen, ovary, bone marrow, and liver were the most active. These most active tissues are those with fenestrated or discontinuous capillary beds, suggesting that exposure to high concentrations of albumin is an important determinant of their high rates of albumin degradation.