Intracellular pH regulation in rabbit renal medullary collecting duct cells. Role of chloride-bicarbonate exchange.
Intracellular pH regulation in rabbit renal medullary collecting duct cells. Role of chloride-bicarbonate exchange.
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兔肾髓质集合管细胞的细胞内pH调节。
DOI：
10.1172/jci112486
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Seifter,JL
中科院分区：
文献类型：
--
作者：
Zeidel,ML;Silva,P;Seifter,JL
肾髓质集合管（MCD）将质子分泌到其管腔中，并将HCO 3分泌到其基底外侧间隙中。基底外侧HCO 3转运被认为通过Cl/HCO 3交换发生。为了进一步表征该Cl/HCO 3交换过程，在新鲜制备的兔外MCD细胞中监测细胞内pH（pHi）调节。通过蛋白酶消化分离细胞，并通过Ficoll梯度离心纯化。使用包埋的胞质内pH指示剂6-羧基荧光素通过荧光测定法估计pHi。将细胞在含碳酸氢盐的溶液中预孵育，然后突然稀释到不含碳酸氢盐的培养基中。MCD细胞pHi对突然去除CO2/HCO 3的反应包括由于CO2快速流出而导致的初始碱化，随后由于HCO 3流出而导致的酸化，以及部分由于质膜H+-ATP酶的作用而逐渐恢复至7.24 +/- 0.06的静息pHi。初始碱化需要CO2/HCO 3梯度，在乙酰唑胺存在下不会发生。酸化阶段需要细胞内HCO 3和细胞外Cl，这与Cl/HCO 3交换一致。MCD HCO 3外排对细胞外Cl表现出饱和动力学，米氏常数（Km）为29.9 +/- 7.7 mM。HCO 3外排还表现出对卤化物的偏好，而不是NO3、SCN和葡萄糖酸盐，对二磺酸芪和乙酰唑胺的抑制具有惊人的敏感性，对DIDS的表观K1为5 X 10（-7）M。最终pHi恢复需要细胞内ATP，这表明Cl/HCO 3和H+-ATP酶活性存在于这些悬浮液中的相同细胞中。结果提供了直接的证据MCD Cl/HCO 3交换，并描述了这种运输过程的一些属性。
The renal medullary collecting duct (MCD) secretes protons into its lumen and HCO3 into its basolateral space. Basolateral HCO3 transport is thought to occur via Cl/HCO3 exchange. To further characterize this Cl/HCO3 exchange process, intracellular pH (pHi) regulation was monitored in freshly prepared rabbit outer MCD cells. Cells were separated by protease digestion and purified by Ficoll gradient centrifugation. pHi was estimated fluorometrically using the entrapped intracytoplasmic pH indicator, 6-carboxyfluorescein. Cells were preincubated in bicarbonate-containing solutions and then abruptly diluted into bicarbonate-free media. The MCD cell pHi response to abrupt removal of CO2/HCO3 included an initial alkalinization due to rapid CO2 efflux, followed by an acidification due to HCO3 efflux and a gradual recovery to the resting pHi of 7.24 +/- 0.06 partly due to the action of a plasma membrane H+-ATPase. The initial alkalinization required a CO2/HCO3 gradient and did not occur in the presence of acetazolamide. The acidification phase required intracellular HCO3 and extracellular Cl, which was consistent with a Cl/HCO3 exchange. MCD HCO3 efflux exhibited saturable kinetics for extracellular Cl, with a Michaelis constant (Km) of 29.9 +/- 7.7 mM. HCO3 efflux also exhibited preference for halides over NO3, SCN, and gluconate, and striking sensitivity to disulfonic stilbene and acetazolamide inhibition, with an apparent K1 of 5 X 10(-7) M for DIDS. The final pHi recovery required intracellular ATP, which indicated that Cl/HCO3 and H+-ATPase activities are present in the same cells in these suspensions. The results provide direct evidence for MCD Cl/HCO3 exchange and describe some of the properties of this transport process.
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兔髓质集合管酸化的阴离子依赖性。
DOI：
10.1172/jci110905
发表时间：
1983
期刊：
The Journal of clinical investigation
影响因子：
--
作者：
Stone,DK;Seldin,DW;Kokko,JP;Jacobson,HR
通讯作者：
Jacobson,HR
DOI：
10.1152/ajprenal.1985.248.4.f500
发表时间：
1985
期刊：
The American journal of physiology
影响因子：
--
作者：
Koeppen,BM
通讯作者：
Koeppen,BM
DOI：
10.1172/jci110760
发表时间：
1983
期刊：
The Journal of clinical investigation
影响因子：
--
作者：
Davis,GR;Morawski,SG;SantaAna,CA;Fordtran,JS
通讯作者：
Fordtran,JS
影响因子：
--
作者：
LOMBARD, WE;KOKKO, JP;JACOBSON, HR
通讯作者：
JACOBSON, HR
证明肠刷状缘膜中电生 Na 依赖性 D-葡萄糖转运。
DOI：
--
发表时间：
1974
影响因子：
11.1
作者：
H. Murer;U. Hopfer
通讯作者：
U. Hopfer