Evidence for gut factor in K+ homeostasis.
Evidence for gut factor in K+ homeostasis.
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K 稳态中肠道因子的证据。
DOI：
10.1152/ajprenal.00427.2006
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Youn,JangH
中科院分区：
文献类型：
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作者：
Lee,FelixN;Oh,Gisuk;McDonough,AliciaA;Youn,JangH
我们测试了这样的假设：K+摄入是由内脏区域的假定K+传感器感知的，并且肾脏K+处理受该信号调节。通过颈静脉（全身输注）、肝门静脉（门静脉内输注）或胃（胃内输注）（各n = 5）将K+输注至禁食过夜的大鼠2小时，并在2小时预输注、2小时K+输注和3小时冲洗期间测量血浆K+浓度（[K+]）和肾K+排泄。全身K+输注期间，血浆[K+]增加约1.3 mM（P<0.05），并且在K+输注停止后，血浆[K+]在1-2小时内降至输注前水平。肾 K+ 排泄量的变化与血浆 [K+] 的变化成比例。在门静脉内或胃内 K+ 输注过程中，血浆 [K+] 和肾脏 K+ 排泄情况与全身输注相似。在用缺乏 K+ 的饮食同时喂养禁食过夜的大鼠期间，还研究了通过不同途径（各 n= 5 或 6）输注 K+ 的效果。进餐期间，门静脉输注导致血浆[K+]增加，与全身K+输注相似，而胃内K+输注并没有显着增加血浆[K+]。因此，当胃内K+输注与膳食结合时，K+输注的清除率显着增强，这与肾脏K+排泄效率的明显增加相关。这些数据表明，可能存在一种肠道因素，可以提高膳食（或膳食 K+）摄入期间 K+ 排泄的肾脏效率。
We tested the hypothesis that K+intake is sensed by putative K+sensors in the splanchnic areas, and renal K+handling is regulated by this signal. K+was infused for 2 h into overnight-fasted rats via the jugular vein (systemic infusion), hepatic portal vein (intraportal infusion), or stomach (intragastric infusion) (n= 5 each), and plasma K+concentration ([K+]) and renal K+excretion were measured during the 2-h preinfusion, 2-h K+infusion, and 3-h washout periods. During systemic K+infusion, plasma [K+] increased by ∼1.3 mM (P< 0.05), and, on cessation of the K+infusion, plasma [K+] fell to the preinfusion level within 1–2 h. Renal K+excretion changed in proportion to the changes in plasma [K+]. During intraportal or intragastric K+infusion, plasma [K+] and renal K+excretion profiles were similar to those with systemic infusion. The effects of K+infusions via the different routes (n= 5 or 6 each) were also studied during simultaneous feeding of overnight-fasted rats with a K+-deficient diet. During the meal, intraportal infusion resulted in increases in plasma [K+] similar to those with the systemic K+infusion, while intragastric K+infusion did not significantly increase plasma [K+]. Thus, when the intragastric K+infusion was combined with a meal, there was marked enhancement of clearance of the K+infused, which was associated with an apparent increase in renal efficiency of K+excretion. These data suggest that there may be a gut factor that enhances renal efficiency of K+excretion during meal (or dietary K+) intake.