Inhibition of Na,K-ATPase by an endotoxin extracted from Leptospira interrogans: A possible mechanism for the physiopathology of leptospirosis
| Autor: | Younes-Ibrahim, M., Burth, P., Castro Faria, M. V., Bénédicte Buffin-Meyer, Marsy, S., Barlet-Bas, C., Cheval, L., Doucet, A. |
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| Přispěvatelé: | Unité de biologie cellulaire et moléculaire, Institut National de la Recherche Agronomique (INRA), Institut de génétique humaine (IGH), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Cheval, Lydie |
| Předmět: |
MESH: Leptospira interrogans
Kidney Medulla Dose-Response Relationship Drug [SDV]Life Sciences [q-bio] MESH: Rabbits MESH: Kidney MESH: Leptospirosis Kidney Epithelium MESH: Dose-Response Relationship Drug [SDV] Life Sciences [q-bio] Endotoxins MESH: Epithelium MESH: Endotoxins Animals MESH: Animals Leptospirosis Rabbits Leptospira interrogans Sodium-Potassium-Exchanging ATPase MESH: Kidney Medulla MESH: Sodium-Potassium-Exchanging ATPase |
| Zdroj: | Scopus-Elsevier Comptes rendus de l’Académie des sciences. Série III, Sciences de la vie Comptes rendus de l’Académie des sciences. Série III, Sciences de la vie, Elsevier, 1995, 318 (5), pp.619-25 |
| Popis: | International audience; Clinical manifestations of leptospirosis include disorders of the electrolytical balance which might be related to inhibition of Na,K-ATPase. Although the physiopathological cellular mechanism of leptospirosis remains unknown, a bacterial endotoxin has been incriminated. Therefore, we evaluated whether a glycolipoprotein fraction extracted from Leptospira interrogans and known to be cytotoxic might inhibit Na,K-ATPase. This glycolipoprotein fraction (GLP) inhibited Na,K-ATPase activity in rabbit kidney epithelial cells as well as Na,K-ATPase purified from rabbit kidney medulla. Inhibition was dose-dependent, and at maximum it almost abolished Na,K-ATPase activity whereas it had no effect on other enzymes. The GLP did not change the apparent affinity of Na,K-ATPase for potassium whereas it increased that for sodium, revealing a mechanism of inhibition different from that of ouabain. Finally, the inhibitory principle present in the GLP preparation was thermostable and was curtailed by the presence of albumin. In conclusion, a glycolipoproteic fraction extracted from Leptospira interrogans contains a specific inhibitor of Na,K-ATPase. This glycolipoproteic fraction which is present in diseased tissues might induce, through this inhibitor, cellular dysfunctions responsible for the symptoms, in particular those associated with electrolytical disorders such as disturbances of renal electrolyte handling, cardiac arrhythmia or diarrhoea. |
| Databáze: | OpenAIRE |
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