An in vivo microperfusion study of distal tubule bicarbonate reabsorption in normal and ammonium chloride rats.
An in vivo microperfusion study of distal tubule bicarbonate reabsorption in normal and ammonium chloride rats.
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正常大鼠和氯化铵大鼠远端小管碳酸氢盐重吸收的体内微灌注研究。
DOI：
10.1172/jci111735
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
D. Levine
中科院分区：
文献类型：
--
作者：
D. Levine
多年来，人们一直认为远端肾单位氢离子分泌可以通过钠输送、钠亲和力和钾储存等因素进行重要调节。自由流动微穿刺研究还表明，碳酸氢盐输送速率也可能改变碳酸氢盐重吸收速率。本研究旨在检验管腔对大鼠体内微灌注远端小管总二氧化碳重吸收的可能影响。用五种溶液灌注正常和酸中毒大鼠的肾小管，以诱导碳酸氢盐负荷、钠和钾通量（JNa、JK）以及管腔硫酸盐浓度变化的方式。在每份收集的灌注液中，使用石墨炉原子吸收光谱法测定水重吸收、Na 和 K 浓度，并通过微量热法测定总 CO2 浓度。使用协方差因子分析来解释对总 CO2 通量 (JtCO2) 的混杂影响，例如水重吸收，酸中毒大鼠的远端肾小管重吸收 CO2 范围为 50-112 pmol X min-1 X mm-1 X 这些 JtCO2 值与 HCO3 负荷、JNa 或 JK 没有显着相关，尽管后者从净重吸收到净分泌发生了变化。酸碱状态正常的大鼠远端肾小管的JtCO2值与零没有显着差异，也不与JK和JNa的变化相关。此外，将负荷从 250-500 pmol/min 加倍（通过将 25 mM HCO3 溶液的灌注速率加倍）不会刺激这些正常动物中的 JtCO2。因此，这些急性体内微灌注研究首次表明，负荷、钾或钠通量都不是远端小管碳酸氢盐重吸收的重要调节剂。
For many years it has been thought that distal nephron hydrogen ion secretion can be importantly modulated by factors such as sodium delivery, sodium avidity, and potassium stores. Free flow micropuncture studies have also indicated that the rate of bicarbonate delivery may also alter the rate of bicarbonate reabsorption. The present studies were undertaken to examine possible luminal influences on total CO2 reabsorption in microperfused distal tubules in the rat in vivo. Tubules from normal and acidotic rats were perfused with five solutions in a manner that induced changes in bicarbonate load, sodium and potassium fluxes (JNa, JK), and luminal sulfate concentration. in each collected perfusate, simultaneous analyses were undertaken to determine water reabsorption, Na, and K concentrations using graphite furnace atomic absorption spectroscopy and total CO2 by microcalorimetry. Using factorial analysis of covariance to account for confounding effects on total CO2 flux (JtCO2) such as water reabsorption, distal tubules of acidotic rats reabsorbed CO2 in the range of 50-112 pmol X min-1 X mm-1 X These JtCO2 values were not significantly correlated with HCO3 load, JNa, or JK despite changes in the latter from net reabsorption to net secretion. Distal tubules of rats with normal acid-base status had JtCO2 values which were neither significantly different from zero nor correlated with changes in JK and JNa. Further, doubling the load from 250-500 pmol/min (by doubling the perfusion rate of 25-mM HCO3 solutions) did not stimulate JtCO2 in these normal animals. Accordingly, these acute in vivo microperfusion studies indicate for the first time that neither load nor potassium or sodium fluxes are important modulators of distal tubule bicarbonate reabsorption.
盐皮质激素调节兔髓质集合管酸化。
DOI：
10.1172/jci110986
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
急性代谢性酸中毒会增加大鼠集合管酸化率。
DOI：
10.1152/ajprenal.1981.241.6.f669
发表时间：
1981
期刊：
The American journal of physiology
影响因子：
--
作者：
Graber,ML;Bengele,HH;Mroz,E;Lechene,C;Alexander,EA
通讯作者：
Alexander,EA
大鼠远曲小管中碳酸氢盐转运的评估：酸碱状态的影响。
DOI：
10.1152/ajprenal.1982.243.4.f335
发表时间：
1982
期刊：
The American journal of physiology
影响因子：
--
作者：
Lucci,MS;Pucacco,LR;Carter,NW;DuBoseJr,TD
通讯作者：
DuBoseJr,TD