大鼠尿PCO2升高：一种肾内事件。

Elevated urinary PCO2 in the rat: an intrarenal event.

作者信息

Graber M L, Bengele H H, Alexander E A

出版信息

Kidney Int. 1982 Jun;21(6):795-9. doi: 10.1038/ki.1982.101.

DOI:10.1038/ki.1982.101

Abstract

During a bicarbonate diuresis, final urine Pco2 considerably exceeds systemic Pco2, an effect thought to reflect the postpapillary delayed dehydration of carbonic acid. To test this explanation, Pco2 tensions along the inner medullary collecting duct (IMCD) of bicarbonate-loaded rats were measured directly using Pco2 microelectrodes. With systemic Pco2 held at 40 mm Hg, IMCD Pco2 exceeded systemic Pco2 in every measurement by an average of 20 to 30 mm Hg. A significant increment in Pco2 was seen between 50% IMCD length and the papilla tip. During the infusion of carbonic anhydrase, IMCD Pco2 was reduced but not to systemic levels. Finding elevated Pco2 along the terminal IMCD deemphasizes the importance of postpapillary delayed dehydration and suggests the possibility that bicarbonaturia is associated with papillary accumulation of carbon dioxide.

摘要

在进行重碳酸盐利尿时，终尿Pco₂显著超过全身Pco₂，这一效应被认为反映了碳酸在乳头后延迟脱水。为验证这一解释，使用Pco₂微电极直接测量了碳酸氢盐负荷大鼠的髓质内集合管（IMCD）沿线的Pco₂张力。在全身Pco₂维持于40 mmHg时，每次测量中IMCD的Pco₂均超过全身Pco₂，平均高出20至30 mmHg。在IMCD长度的50%至乳头尖端之间可观察到Pco₂显著升高。在输注碳酸酐酶期间，IMCD的Pco₂有所降低，但未降至全身水平。在IMCD末端发现Pco₂升高，这降低了乳头后延迟脱水的重要性，并提示了碱尿症与乳头二氧化碳蓄积相关的可能性。