Bengele H H, Graber M L, Alexander E A
Am J Physiol. 1983 Jan;244(1):F89-94. doi: 10.1152/ajprenal.1983.244.1.F89.
The effect of acute respiratory acidosis (ARA) on inner medullary collecting duct (IMCD) acidification was studied and the results were compared with previously obtained data by our laboratory in rats with acute metabolic acidosis (AMA). We employed the microcatheterization technique to directly measure pH and PCO2 with glass-membrane electrodes, and fluid samples were obtained for measurement of bicarbonate, phosphate, and ammonium. Arterial pH was 7.18 +/- 0.01 and PCO2 was 88 +/- 2 mmHg. The IMCD data were analyzed as a function of IMCD length (approximately 6 mm). pH decreased from 5.78 +/- 0.07 to 5.27 +/- 0.03 and PCO2 increased from 55 +/- 4 to 75 +/- 2 mmHg between origin and tip. Bicarbonate delivery decreased from 154 +/- 34 to 25 +/- 3 nmol/min but no change was noted in acid phosphate, ammonium, or net acid addition along the IMCD. However, net acid excretion was not different from that found previously in AMA. We conclude that during ARA acidification is augmented prior to, but not along, the IMCD. In contrast, during AMA we previously found that IMCD plays a major regulatory role in urinary acidification, accounting for about 50% of the excreted hydrogen ion.
研究了急性呼吸性酸中毒（ARA）对肾内髓集合管（IMCD）酸化的影响，并将结果与我们实验室之前在急性代谢性酸中毒（AMA）大鼠中获得的数据进行了比较。我们采用微导管插入技术，用玻璃膜电极直接测量pH值和PCO₂，并获取液体样本以测量碳酸氢盐、磷酸盐和铵。动脉pH值为7.18±0.01，PCO₂为88±2 mmHg。IMCD数据作为IMCD长度（约6 mm）的函数进行分析。在起始端和末端之间，pH值从5.78±0.07降至5.27±0.03，PCO₂从55±4升至75±2 mmHg。碳酸氢盐输送量从154±34降至25±3 nmol/min，但沿IMCD的酸性磷酸盐、铵或净酸添加量没有变化。然而，净酸排泄与之前在AMA中发现的情况没有差异。我们得出结论，在ARA期间，IMCD之前的酸化增强，但沿IMCD的酸化没有增强。相比之下，在AMA期间，我们之前发现IMCD在尿液酸化中起主要调节作用，约占排泄氢离子的50%。
