Details

Autor(en) / Beteiligte

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

Titel

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

Ist Teil von

• American journal of physiology. Renal physiology, 1991-09, Vol.261 (3), p.386-F392

Ort / Verlag

United States

Erscheinungsjahr

1991

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• W. H. Dantzler, S. H. Wright, V. Chatsudthipong and O. H. Brokl Department of Physiology, College of Medicine, University of Arizona, Tucson 85724. 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 [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 demonstrated 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.