EFFECT OF CHRONIC POTASSIUM LOADING ON POTASSIUM SECRETION BY PARS RECTA OR DESCENDING LIMB OF JUXTAMEDULLARY NEPHRON IN RAT
EFFECT OF CHRONIC POTASSIUM LOADING ON POTASSIUM SECRETION BY PARS RECTA OR DESCENDING LIMB OF JUXTAMEDULLARY NEPHRON IN RAT
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DOI：
10.1172/jci109215
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发表时间：
1978-01-01
影响因子：
15.9
通讯作者：
JAMISON, RL
中科院分区：
文献类型：
--
作者：
BATTILANA, CA;DOBYAN, DC;JAMISON, RL
Kn分泌的直部或降支的延髓肾单位被证明。研究了慢性高钾摄入对这种现象的影响。与正常缺水大鼠相比，延髓近端肾单位对水和钠的重吸收分数降低。有一个显着增加的分数过滤K在结束的延髓降支从94 ±。11%至180 .+-. 18%，这主要是由于K分泌增加。当给予阿米洛利后K-负荷大鼠的集合小管液中K的浓度降低时，观察到到达降支末端的K量急剧下降（64 ± 0.01）。8%）。降支末滤过钾分数与末次尿钾浓度呈正相关（P < 0.001）。钾，像尿素，通常经历髓再循环，这是增强慢性钾负荷。
Kn secretion by the pars recta or by the descending limb of the juxtamedullary nephron was demonstrated. The effect of a chronic high-K intake on this phenomenon was studied. Fractional reabsorption of water and Na by the juxtamedullary proximal nephron was decreased when compared to that in normal hydropenic rats. There was a striking increase in the fraction of filtered K at the end of the juxtamedullary descending limb from 94 .+-. 11% to 180 .+-. 18%, which was principally a result of enhanced K secretion. When the concentration of K in the collecting tubule fluid of K-loaed rats was reduced after the administration of amiloride, a sharp fall was observed in the amount of K which reached the end of the descending limb (64 .+-. 8%). A direct correlation was observed between the fraction of filtered K at the end of the descending limb and the K concentration in the final urine (P < 0.001). K, like urea, normally undergoes medullary recycling, which is enhanced by chronic K loading.