Amino acids enhance renal tubular absorption of the los-molecular-weight proteins insulin and growth hormone.
Amino acids enhance renal tubular absorption of the los-molecular-weight proteins insulin and growth hormone.
复制标题
氨基酸增强肾小管对低分子量蛋白质胰岛素和生长激素的吸收。
DOI：
10.1152/ajprenal.1982.242.6.f745
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Tsao,TS
中科院分区：
文献类型：
--
作者：
Rabkin,R;Gottheiner,TI;Tsao,TS
在离体大鼠肾脏中研究了氨基酸（AA）对低分子量（LMW）蛋白肾小管吸收的影响。用白蛋白电解质溶液灌注肾脏，该溶液含有胰岛素或人生长激素（hGH），除非另有说明，还含有以下L-氨基酸：甘氨酸、异亮氨酸、丝氨酸、丙氨酸、甲硫氨酸、脯氨酸、精氨酸和天冬氨酸。在没有 AA 灌注的肾脏中，尿胰岛素清除率 (FCi) 平均为 7.4 +/- 1.54%，而在存在多种 AA 的情况下，FCi 显着较低（0.68 +/- 0.2%，P 小于 0.01）。单独添加甘氨酸或 α-氨基异丁酸 (AIB) 也显着降低 FCi（分别为 1.79 +/- 0.66 和 1.59 +/-1.06%）。相比之下，单独灌注其他 AA 不会改变 FCi。灌注多种 AA 的肾脏的尿 hGH 清除率分数 (0.94 +/- 0.47%) 也显着低于灌注无 AA 的肾脏 (9.07 +/- 1.2%)。我们得出的结论是，AA 的存在增强了肾小管对过滤胰岛素和 hGH 的吸收。其机制尚不清楚，但单独使用甘氨酸和 AIB 即可增强胰岛素吸收。这提出了胰岛素吸收与甘氨酸和 AIB 共享转运系统之间存在联系的可能性，但排除了主要代谢效应，因为 AIB 是不可代谢的。
The effect of amino acids(AA) on the tubular absorption of low-molecular-weight (LMW) proteins was studied in isolated rat kidneys. Kidneys were perfused with an albumin-electrolyte solution that contained insulin or human growth hormone (hGH) and, unless otherwise stated, the following L-amino acids: glycine, isoleucine, serine, alanine, methionine, proline, arginine, and aspartic acid. In kidneys perfused without AA, fractional urinary insulin clearance (FCi) averaged 7.4 +/- 1.54%, whereas in the presence of multiple AA the FCi was significantly lower (0.68 +/- 0.2%, P less than 0.01). Addition of glycine or alpha-aminoisobutyric acid (AIB) alone also reduced the FCi significantly (1.79 +/- 0.66 and 1.59 +/-1.06%, respectively). By contrast, perfusion with the other AA individually did not alter the FCi. The fractional urinary hGH clearance was also significantly lower in kidneys perfused with multiple AA (0.94 +/- 0.47%) than in those perfused without AA (9.07 +/- 1.2%). We conclude that tubular absorption of filtered insulin and hGH is enhanced by the presence of AA. The mechanism is unclear, but enhancement of insulin absorption can be produced by glycine and AIB alone. This raises the possibility of a link between the absorption of insulin and the glycine and AIB shared transport system, but excludes a primary metabolic effect because AIB is nonmetabolizable.