Absence of vacuolar H+-ATPases from rat small intestine brush-border membranes.
Rat small intestinal brush-border membrane (BBM) vesicles were solubilized to test for the presence of an intravesicular H+-ATPase. Several detergents that in rat renal BBM vesicles revealed a bafilomycin-sensitive H+-ATPase failed to expose a similar ATPase in small intestinal vesicles. Antibodies against the 31-kDa and 70-kDa H+-ATPase subunits labelled respective antigens in the BBM of renal proximal tubules, but not in the BBM of enterocytes. The results demonstrate that a bafilomycin-sensitive, vacuolar-type H+-ATPase is absent from the BBM of enterocytes and, hence, cannot contribute to H+ secretion.
Sabolic
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Institute for Medical Research and Occupational Health, 10001 Zagreb, Croatia.
Herak-Kramberger
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CM
Schweickhardt
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Burckhardt
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D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019084:Fluorescent Antibody Technique, Indirect; D007421:Intestine, Small / Q000201:enzymology*; D018942:Macrolides; D008871:Microvilli / Q000201:enzymology; D017830:Octoxynol / Q000494:pharmacology; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014617:Vacuoles / Q000201:enzymology*
D000900:Anti-Bacterial Agents; D003902:Detergents; D004791:Enzyme Inhibitors; D018942:Macrolides; C057620:bafilomycin A; D017830:Octoxynol; D006180:Proton-Translocating ATPases