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| COLOCALIZATION OF H+-ATPASE AND BAND-3 ANION-EXCHANGER IN RABBIT COLLECTING DUCT INTERCALATED CELLS |
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| Author(s): SCHUSTER VL, FEJESTOTH G, NARAYFEJESTOTH A, GLUCK S |
| Source: AMERICAN JOURNAL OF PHYSIOLOGY Volume: 260 Issue: 4 Pages: F506-F517 Part: Part 2 Published: APR 1991 |
| Times Cited: 99 References: 58 |
| Abstract: Two major types of intercalated cells (IC) have been previously defined in rabbit collecting duct: alpha-cells have a basolateral band 3-like anion exchanger and secrete H+, whereas beta-cells bind peanut agglutinin (PNA) apically and are believed to secrete HCO3-. To further define IC types, we double-labeled kidney sections with anti-H+-ATPase antibodies and with either an anti-band 3 antibody or PNA. We found four patterns of staining: 1) IC with apical H+-ATPase and basal band 3, a configuration consistent with ongoing H+ secretion, which prevailed in the inner stripe of outer medulla (OMCD(i)); 2) diffuse H+-ATPase labeling across the cell and basal band 3, which was most numerous in the outer stripe of outer medulla (OMCD(o)); 3) IC with "bright" apical peanut lectin, diffuse H+-ATPase, and no band 3, which was abundant in the cortical collecting duct (CCD) and probably represents HCO3--secreting cells; and 4) "hybrid" cells with various staining combinations (e.g., apical lectin binding and apical H+-ATPase), which although they are uncommon, were seen in the CCD. Consistent with this immunocytochemical finding of hybrid cells, cell-sorting studies on isolated CCD IC showed that 6-18% of PNA-positive cells also stained positively for band 3. We conclude that 1) band 3-positive IC in the OMCD vary axially. Most OMCD(i) IC are probably active proton secretors, whereas up to one-half of OMCD(o) IC may be latent H+ secretors. 2) The diffuse H+-ATPase pattern in putative beta-cells differs from comparable results in the rat and is not consistent with a "reversed" alpha-cell. HCO3- secretion by beta-cells may be driven by an H+ extrusion mechanism other than the alpha-cell pump re-sorted to the basolateral membrane. 3) The possibility of hybrid cells that might combine alpha- and beta-cell transport proteins suggests a mechanism for functional reversal of collecting duct IC polarity. |
| Document Type: Article |
| Language: English |
Addresses:
1. UNIV IOWA, DIV RENAL, IOWA CITY, IA 52242 USA
2. YESHIVA UNIV ALBERT EINSTEIN COLL MED, BRONX, NY 10461 USA
3. HENRY FORD HOSP, DIV HYPERTENS RES, DETROIT, MI 48202 USA
4. WASHINGTON UNIV, DEPT MED, ST LOUIS, MO 63110 USA
5. WASHINGTON UNIV, DEPT CELL BIOL, ST LOUIS, MO 63110 USA
6. WASHINGTON UNIV, DEPT PHYSIOL, ST LOUIS, MO 63110 USA
7. WASHINGTON UNIV, SCH MED, ST LOUIS, MO 63110 USA
8. JEWISH HOSP ST LOUIS, DIV RENAL, ST LOUIS, MO 63110 USA |
| Publisher: AMER PHYSIOLOGICAL SOC, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 |
| Subject Category: Physiology |
| IDS Number: FG542 |
| ISSN: 0002-9513 |
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