Basolateral tetraethylammonium transport in intact tubules: Specificity and trans-stimulation

W. H. Dantzler, S. H. Wright, V. Chatsudthipong, O. H. Brokl

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

To examine the specificity of proximal renal basolateral organic cation transport, the effects of unlabeled organic cation substrates in the bathing medium on the rate of uptake of [14C]tetraethylammonium ([14C]TEA) by intact nonperfused proximal tubules and isolated basolateral membrane vesicles (BLMV) from rabbit kidneys were explored. The pattern of inhibition of transport by a battery of unlabeled organic cations was similar in intact tubules and BLMV. To determine if trans-stimulation could be demonstrated across the basolateral membrane of intact tubules, the effects of preloading tubules with unlabeled substrates on the rate of uptake of [14C]TEA and the effects of unlabeled substrates in the bathing medium on the rate of efflux of [14C]TEA from tubules preloaded with this labeled substrate were examined. Trans-stimulation was clearly demonstratrated for the first time in intact tubules. However, of the compounds that significantly inhibited [14C]TEA uptake (TEA, amiloride, tetrapropylammonium, mepiperphenidol, isopropyl pyridinium, and choline), only TEA itself and choline produced a trans-stimulation of [14C]TEA uptake. Moreover, choline appeared to be at least as effective as TEA itself as a counter ion for TEA transport. Such trans-stimulation could play a physiological role in the net reabsorption of choline and the net secretion of most other organic cations.

Original languageEnglish (US)
Pages (from-to)F386-F392
JournalAmerican Journal of Physiology - Renal Fluid and Electrolyte Physiology
Volume261
Issue number3 30-3
DOIs
StatePublished - 1991

Keywords

  • Organic cations
  • Proximal tubules
  • Rabbits

ASJC Scopus subject areas

  • Physiology

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