4.7 Article

Angiotensin I conversion to angiotensin II stimulates cortical collecting duct sodium transport

期刊

HYPERTENSION
卷 42, 期 2, 页码 195-199

出版社

LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1161/01.HYP.0000081221.36703.01

关键词

angiotensin-converting enzyme; imaging; kallikrein; kidney; rabbits; renin-angiotensin system

资金

  1. PHS HHS [32032] Funding Source: Medline

向作者/读者索取更多资源

Angiotensin (Ang) II directly stimulates epithelial sodium channel activity in the rabbit cortical collecting duct. Because Ang I and converting enzyme analogues might be present in the distal nephron, this raises the possibility of intraluminal generation of Ang II. Conversion of Ang I to Ang II was monitored by Ang II - dependent changes in intracellular sodium concentration as a reflection of sodium transport across the apical membrane. This involved imaging-based fluorescence microscopy with sodium-binding benzofuran isophthalate in isolated, perfused, cortical collecting-duct segments from rabbit kidney. Principal and intercalated cells were differentiated by rhodamine-conjugated peanut lectin. Control principal cell intracellular sodium concentration, during perfusion with 25 mmol/L NaCl and zero sodium in the bath plus monensin (10(-5) mol/L) averaged 5.8 +/- 0.14 mmol/L (n = 156). The increase in intracellular sodium concentration, when luminal NaCl was increased from 25 to 150 mmol/L, was elevated by 3.5- fold in the presence of intraluminal Ang I (10(-6) mol/L). Also, the effects of Ang I on sodium transport were not significantly different from the effects of Ang II (10(-9) mol/L). Ang I was used in micromolar concentrations to ensure that there was sufficient substrate available for conversion to Ang II. Inhibition of the angiotensin-converting enzyme with captopril reduced the stimulatory effect of Ang I. These results suggest that intraluminal conversion of Ang I to Ang II can occur in the cortical collecting duct, resulting in enhanced apical sodium entry.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据