内皮素通过降低大鼠近端直小管中钠钾ATP酶的活性，部分抑制液体和碳酸氢盐的转运。

Endothelin inhibits fluid and bicarbonate transport in part by reducing Na+/K+ ATPase activity in the rat proximal straight tubule.

作者信息

Garvin J, Sanders K

机构信息

Department of Medicine, Henry Ford Hospital, Detroit, MI 48202.

出版信息

J Am Soc Nephrol. 1991 Nov;2(5):976-82. doi: 10.1681/ASN.V25976.

DOI:10.1681/ASN.V25976

PMID:1662089

Abstract

The effects of endothelin on fluid and bicarbonate absorption and Na+/K+ ATPase activity in the proximal straight tubule were investigated. During the control period, fluid absorption was 0.59 +/- 0.03 nL/mm.min when tubules were perfused at 4.76 nL/mm.min. After treatment with 10(-9) M endothelin, fluid absorption fell to 0.36 +/- 0.06 nL/mm.min when perfused at a similar flow rate. During the control period, bicarbonate absorption was 67.9 +/- 3.6 pmol/mm.min. After treatment with endothelin, it fell to 42.8 +/- 4.3 pmol/mm.min, an inhibition of 38%. To test whether inhibition of fluid and bicarbonate absorption was due to suppression of Na+/K+ ATPase activity, the effect of endothelin on pump activity was investigated. In control tubules, Na+/K+ ATPase activity was 85 +/- 5 pmol/mm.min. In endothelin-treated tubules, Na+/K+ ATPase activity was 68 +/- 4 pmol/mm.min, a reduction of 20%. From these data, it was concluded that endothelin inhibits fluid and bicarbonate transport in the proximal tubule and that this inhibition is in part due to suppression of Na+/K+ ATPase activity.

摘要

研究了内皮素对近端直小管中液体和碳酸氢盐吸收以及Na⁺/K⁺ ATP酶活性的影响。在对照期，当以4.76 nL/mm·min的流速灌注小管时，液体吸收量为0.59±0.03 nL/mm·min。用10⁻⁹ M内皮素处理后，在相似流速下灌注时，液体吸收量降至0.36±0.06 nL/mm·min。在对照期，碳酸氢盐吸收量为67.9±3.6 pmol/mm·min。用内皮素处理后，降至42.8±4.3 pmol/mm·min，抑制率为38%。为了测试液体和碳酸氢盐吸收的抑制是否是由于Na⁺/K⁺ ATP酶活性的抑制，研究了内皮素对泵活性的影响。在对照小管中，Na⁺/K⁺ ATP酶活性为85±5 pmol/mm·min。在内皮素处理的小管中，Na⁺/K⁺ ATP酶活性为68±4 pmol/mm·min，降低了20%。从这些数据得出结论，内皮素抑制近端小管中的液体和碳酸氢盐转运，并且这种抑制部分是由于Na⁺/K⁺ ATP酶活性的抑制。