Salt intake determines the renal response to L-arginine infusion in normal human subjects
Salt intake determines the renal response to L-arginine infusion in normal human subjects
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DOI：
10.1046/j.1523-1755.1998.00857.x
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发表时间：
1998-05-01
影响因子：
19.6
通讯作者：
Wilcox, CS
中科院分区：
文献类型：
--
作者：
Barri, YM;Wilcox, CS
在实验动物中的研究表明，肾脏中由L-精氨酸产生的一氧化氮（NO）参与了肾功能对盐摄入量变化的适应，但缺乏对人类受试者的类似研究。因此，我们在8名正常人受试者中比较了30 g L-精氨酸与30 g支链氨基酸（对照）的输注，在5至7天的低盐平衡后（LS; 20 mmol . 24 hr（-1））或高盐（HS; 200 mmol . 24小时（-1））摄入。锂清除率被用作近端肾小管重吸收的标志。与对照组相比，L-精氨酸没有显著改变血压、菊粉或对氨基马尿酸清除率，但显著增加（P < 0.05）NO2 + NO3（NOx）的排泄（LS，157 +/- 46至210 +/- 48 nmol . min（-1）; HS，138 +/- 30至182 +/- 70）和cGMP（LS，253 +/- 63至337 +/- 76 pmol . min（-1）HS. 311 +/- 68至563 +/- 52）。在低盐摄入（45 +/- 5至21 +/- 3 μ mol . L-精氨酸）期间，min（-1）; P < 0.05），但在高盐摄入（298 +/- 56至537 +/- 84 μ mol . min（-1）; P < 0.05）。计算分数钠重吸收的近端和远端肾单位，从锂和钠的清除率进行评估，增加L-精氨酸在低盐摄入量，但降低L-精氨酸在：高盐摄入量。L-精氨酸显著提高血浆胰岛素浓度（P < 0.05）。这种影响与盐摄入量无关（LS，67 +/- 7至92 +/- 13 ng。ml（-1）; HS，66 +/- 7至76 +/- 9 ng。ml（-1））。L-精氨酸没有显着改变血浆肾素活性。总之，L-精氨酸增加NOx和cGMP的排泄，并增加血浆胰岛素，但对钠排泄的影响取决于盐的摄入量。L-精氨酸在低盐摄入时增强近端和远端肾单位钠重吸收，但在高盐摄入时抑制它。L-精氨酸对NO和cGMP的影响可能与其对钠重吸收的影响有关。
Studies in experimental animals have shown that nitric oxide (NO) generation in the kidney from L-arginine participates in adapting renal function to changes in salt intake, but similar studies in human subjects are lacking. Therefore, we compared the infusion of 30 g of L-arginine to 30 g of branched chain amino acids (control), in eight normal human subjects after 5 to 7 days of equilibration to a low salt (LS; 20 mmol . 24 hr(-1)) or high salt (HS; 200 mmol . 24 hr(-1)) intake. Lithium clearance was used as a marker of proximal tubular reabsorption. Compared to the control infusions, L-arginine did not significantly alter blood pressure, inulin or paraaminohippurate clearance, but significantly increased (P < 0.05) the excretion of NO2 + NO3 (NOx) (LS, 157 +/- 46 to 210 +/- 48 nmol . min(-1); HS, 138 +/- 30 to 182 +/- 70) and cGMP (LS, 253 +/- 63 to 337 +/- 76 pmol . min(-1) HS. 311 +/- 68 to 563 +/- 52). Renal sodium excretion was decreased by L-arginine infusion during the low salt intake (45 +/- 5 to 21 +/- 3 mu mol . min(-1); P < 0.05) but was increased by L-arginine during the high salt intake (298 +/- 56 to 537 +/- 84 mu mol . min(-1); P < 0.05). The calculated fractional reabsorption of sodium in the proximal and distal nephrons, as assessed from lithium and sodium clearances, was increased by L-arginine during the low salt intake but was decreased by L-arginine during the: high salt intake. L-arginine increased plasma insulin concentration significantly (P < 0.05). This effect was independent of salt intake (LS, 67 +/- 7 to 92 +/- 13 ng . ml(-1); HS, 66 +/- 7 to 76 +/- 9 ng . ml(-1)). L-arginine did not significantly alter plasma renin activity. In conclusion, L-arginine increases the excretion of NOx and cGMP and increases plasma insulin, but the effect on sodium excretion depends upon salt intake. L-arginine enhances Na reabsorption in the proximal and distal nephrons during the low salt intake, but inhibits it during the high salt intake. Effects of L-arginine on NO and cGMP may contribute to its effects on Na reabsorption.