The variant chicken kidney AE1 anion exchangers differ only at the NH(2) terminus of their cytoplasmic domains. Transfection studies have indicated that the variant chicken AE1-4 anion exchanger accumulates in the basolateral membrane of polarized MDCK kidney epithelial cells, while the AE1-3 variant, which lacks the NH(2)-terminal 63 amino acids of AE1-4, primarily accumulates in the apical me...

The dicarboxylate, alpha-ketoglutarate (alphaKG), has been identified as the most likely physiological anion involved in renal proximal tubule basolateral membrane (BLM) dicarboxylate/organic anion exchange. In the present study, we characterized the uptake of alphaKG in BLM and brush-border membrane (BBM) vesicles isolated from rat kidney. In both membrane preparations, alphaKG uptake was Na+-...

Current studies were undertaken to characterize the mechanism of short-chain fatty acid (SCFA) transport in isolated human proximal colonic basolateral membrane vesicles (BLMV) utilizing a rapid-filtration n-[(14)C]butyrate uptake technique. Human colonic tissues were obtained from mucosal scrapings from organ donor proximal colons. Our results, consistent with the existence of a HCO(3)(-)/SCFA...

The variant chicken kidney AE1 anion exchangers differ only at the NH 2 terminus of their cytoplasmic domains. Transfection studies have indicated that the variant chicken AE1-4 anion exchanger accumulates in the basolateral membrane of polarized MDCK kidney epithelial cells, while the AE1-3 variant, which lacks the NH 2 -terminal 63 amino acids of AE1-4, primarily accumulates in the apical mem...

A mixture of a carhoxylic acid type of cation exchange resin and a weakly basic anion exchange resin has been used successfully to control the edema of 42 patients wvith congestive heart failure andl the ascites of 14 patients with cirrhosis of the liver. Approximately one-third of the cation exchanger was supplied in the potassium cycle. Inclusion of the anion exchange resin resulted in a grea...

In a heterogeneous electrolyte system of a strongly basic anion exchanger and solutions of NaBF4 or NaClC>4 we established the influence of the nature and concentration of the eluent in chromatographic experiments on chlorine isotope separation. Results show that when the electrolyte concentration is increased the degree of isotope separation decreases. With NaBF4 the separation factor is great...

Anion secretion by colonic epithelium is dependent on apical CFTR-mediated anion conductance and basolateral ion transport. In many tissues, the NKCC1 Na(+)-K(+)-2Cl(-) cotransporter mediates basolateral Cl(-) uptake. However, additional evidence suggests that the AE2 Cl(-)/HCO(3)(-) exchanger, when coupled with the NHE1 Na(+)/H(+) exchanger or a Na(+)-HCO(3)(-) cotransporter (NBC), contributes...

Although many polarized proteins are sorted to the same membrane domain in all epithelial tissues, there are some that exhibit a cell type-specific polarity. We recently found that band 3 (the anion exchanger AE1) was present in the apical membrane of a renal intercalated cell line when these cells were seeded at low density, but its targeting was reversed to the basolateral membrane under the ...

31 Anion secretion by colonic epithelium is dependent on apical CFTR-mediated anion 32 conductance and basolateral ion transport. In many tissues, the NKCC1 Na-K-2Cl 33 cotransporter mediates basolateral Cl uptake. However, additional evidence suggests that the 34 AE2 Cl/HCO3 exchanger, when coupled with the NHE1 Na/H exchanger or a Na-HCO3 35 cotransporter (NBC), contributes to HCO3 and/or Cl ...

Renal organic anion transport systems play an important role in the elimination of drugs, toxic compounds, and their metabolites, many of which are potentially harmful to the body. The renal proximal tubule is the primary site of carrier-mediated transport from blood to urine of a wide variety of anionic substrates. Recent studies have shown that organic anion secretion in renal proximal tubule...