Lack of potassium effect on Na-Cl cotransport in the medullary thick ascending limb.
Lack of potassium effect on Na-Cl cotransport in the medullary thick ascending limb.
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缺乏钾对髓质厚升肢中 Na-Cl 共转运的影响。
DOI：
10.1152/ajprenal.1985.249.1.f34
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Eveloff,J
中科院分区：
文献类型：
--
作者：
Alvo,M;Calamia,J;Eveloff,J
研究了钾对兔肾髓质Henle’s loop厚升肢（mTALH）细胞对氯化钠摄取的影响，以评估钾是否参与Na-Cl共转运系统。1 mM呋塞米在3分钟内抑制70%的Na进入mTALH细胞。氯刺激总钠和速尿敏感钠的摄取。此外，Na梯度刺激Cl进入mTALH细胞，并在3min时被1mm速尿抑制42%。研究了在0、5或140 mM外部钾梯度存在下的钠吸收。在没有钾和存在钾的情况下，Na的摄取是相似的。此外，在没有钾或存在钾的情况下，呋塞米抑制Na的摄取同样有效。钠不刺激86Rb的摄取。在0、5或140 mM Na梯度下，86Rb的摄取相似。速尿对86Rb摄取无明显抑制作用。钡（5mm）是K传导途径的抑制剂，可抑制86Rb的总摄取19%。在5mm BaCl2存在的情况下，Na对86Rb的摄取仍然没有刺激作用。结果证实了在mTALH细胞中存在Na-Cl共转运系统，但在我们使用的实验条件下，不能证明K对NaCl共转运系统的直接影响。
The effect of potassium on sodium chloride uptake into rabbit renal medullary thick ascending limb of Henle's loop (mTALH) cells was studied to assess whether K participates in the Na-Cl cotransport system. Na uptake into the mTALH cells was inhibited 70% at 3 min by 1 mM furosemide. The total and furosemide-sensitive Na uptake was stimulated by Cl. Additionally, Cl uptake into the mTALH cells was stimulated by Na gradients and inhibited 42% at 3 min by 1 mM furosemide. Na uptake was studied in the presence of 0,5, or 140 mM external K gradients. Na uptake was similar in the absence and presence of K. Additionally, furosemide inhibited Na uptake as effectively in the absence or presence of K. Similar studies were conducted to study the effects of Na on 86Rb uptake. Na did not stimulate 86Rb uptake. The uptake of 86Rb was similar in the presence of 0,5, or 140 mM Na gradients. Furosemide had no significant inhibitory effect on 86Rb uptake. Barium (5 mM), an inhibitor of K conductance pathways, inhibited total 86Rb uptake by 19%. In the presence of 5 mM BaCl2, Na still did not have a stimulatory effect on 86Rb uptake. The results confirm the existence of a Na-Cl cotransport system in mTALH cells, but a direct effect of K on the NaCl cotransport system could not be demonstrated under the experimental conditions we used.