MECHANISM OF RENAL ACID-BASE HOMEOSTASIS

拟议议定书的主要目标是更明确地界定 直接测定pH法研究尿酸机理(S)， PCO2，和活体可及肾单位的总CO2浓度 标准皮质部和乳头状显微穿刺术在大鼠肾脏的应用 技巧。在这一系列研究中，将有三个具体领域 调查：(1)确定地震的规模和方向 近曲小管和远曲小管的pH失衡(2) 鲁米那碳酸酐酶在小苏打重吸收中的作用 体内灌流的离体近端小管，以及(3)pH的测定， 二氧化碳分压，以及肾可及节段的总二氧化碳浓度 乳突。这些研究将利用开发的pH和PCO2微电极 在我们的实验室中应用于大鼠微穿刺术，以及 Vurek微量热法测定总二氧化碳 集中精神。这些研究应该能够区分这两者 提出的碳酸氢盐重吸收机制：1)H+分泌，或2) 初级HCO-3重吸收。总而言之，拟议的研究将利用 微电极和微量热技术在评估中的应用 应用皮质和乳头状液直接维持酸碱平衡 微穿刺法和体内微灌注法。

The primary objective of the proposed protocol is to more clearly define the mechanism(s) of urinary acidification by the direct determination of pH, pCO2, and total CO2 concentration in vivo in the accessible nephrons of the rat kidney utilizing standard cortical and papillary micropuncture techniques. In this series of studies, three specific areas will be investigated: (1) determination of the magnitude and direction of the disequilibrium pH in proximal and distal convoluted tubules, (2) contribution of luminal carbonic anhydrase to bicarbonate reabsorption in the in vivo perfused isolated proximal tubule, and (3) determination of pH, pCO2, and total CO2 concentration in the accessible segments of the renal papilla. These studies will utilize pH and pCO2 microelectrodes developed in our laboratory for application in rat micropuncture, as well as the microcalorimetric method of Vurek for determination of total CO2 concentration. These studies should allow differentiation between the two proposed mechanisms of bicarbonate reabsorption: 1) H+ secretion, or 2) primary HCO-3 reabsorption. In summary, the proposed studies will utilize microelectrode and microcalorimetric techniques in concern to evaluate acid-base homeostasis directly by application of cortical and papillary micropuncture and in vivo microperfusion techniques.