Thiazide-sensitive sodium chloride cotransport in early distal tubule.

摘要: At least two pathways mediate sodium absorption across the luminal membrane of renal distal tubule. One pathway is a conductive channel and other appears to be coupled Na-Cl cotransport pathway. The tubule comprises three segments: convoluted tubule, connecting initial collecting duct. To provide information about cellular locations proposed transport pathways, we perfused early (14-38% whole length) late (61-83% segments tubules separately in vivo anesthetized rats. When with solution that resembles fluid normally arriving at (75 mM Na, 68 Cl), rates were similar (early +/- 29.6, 67 27.5 pmol X min-1 mm-1). interstitial (148 110 was significantly higher than (276 28.4 vs. 113 29.7 Chlorothiazide (10(-3) M), which blocks chloride tubules, reduced zero but had no significant effect tubules. Removing all from perfusion solutions not segments.(ABSTRACT TRUNCATED AT 250 WORDS)