title: Cold- and ouabain-resistance of renal Na,K-ATPase in cold-exposed and hibernating jerboas (Jaculus orientalis).
abstract: The temperature dependence and the ouabain sensitivity of Na,K-ATPase was examined in the nephron of normal, cold-exposed, and hibernating jerboas. The transport and hydrolytic activity of renal Na,K-ATPase displayed similar temperature dependence in rats and normal jerboas. Cold-resistance of Na,K-ATPase appeared in cold-exposed jerboas and further increased during hibernation. Three subpopulations of Na,K-ATPase displaying very high (Ki approximately 10(-13) M), high (Ki approximately 10(-9) M) and low sensitivity to ouabain (Ki approximately 10(-6) M) were detected in the thick ascending limb and collecting duct of jerboas. In thick ascending limbs, the subpopulation of very high sensitivity to ouabain disappeared in cold-exposed animals, which accounted for the previously reported decrease in Na,K-ATPase activity. In collecting ducts of cold-exposed animals, the subpopulation of very high sensitivity to ouabain also disappeared, but the resulting decrease in activity was overbalanced by the appearance of the subpopulation of high sensitivity.
authors.affiliation: Laboratoire de Physiologie Animale, Faculté des Sciences, Rabat, Morocco.
authors.forename: C
authors.initials: C
authors.lastname: Bennis
authors.forename: L
authors.initials: L
authors.lastname: Cheval
authors.forename: B
authors.initials: B
authors.lastname: Buffin-Meyer
authors.forename: M
authors.initials: M
authors.lastname: Younes-Ibrahim
authors.forename: C
authors.initials: C
authors.lastname: Barlet-Bas
authors.forename: S
authors.initials: S
authors.lastname: Marsy
authors.forename: A
authors.initials: A
authors.lastname: Doucet
mesh_terms: D000818:Animals; D003080:Cold Temperature; D004305:Dose-Response Relationship, Drug; D005260:Female; D007668:Kidney / Q000187:drug effects*; D008297:Male; D010042:Ouabain / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects*
chemical_list: D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase