[The Na+/H+ exchanger in eukaryotic cells: biochemical and pharmacological properties and physiological role].
A membrane mechanism that catalyses the electroneutral exchange of Na+ for H+ has recently been characterized in a variety of eukaryotic cells. This exchanger is inhibited by amiloride, a potent diuretic drug. It has been implicated in a number of important physiological processes such as the regulation of the intracellular pH, the reabsorption of Na+ by the renal proximal tubule, the regulation of the cell volume and the fertilization of the sea urchin egg. The Na+/H+ exchanger seems able to mediate the action of growth factors. The biochemical and pharmacological properties of the Na+/H+ exchange system are reviewed. They are very similar in the different cell types that have been studied. Yet the Na+/H+ exchange system can fulfil different functions in different cell types depending i) on its properties of interaction with intracellular H+, ii) on the presence of other membrane structures that are involved in the maintenance of transmembrane Na+ and H+ gradients and iii) on the presence of extracellular messages that modify its catalytic properties and, among them, its interaction with internal H+.
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Frelin
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Lazdunski
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D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001667:Binding, Competitive; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D004563:Electrochemistry; D005057:Eukaryotic Cells; D005260:Female; D005306:Fertilization; D005347:Fibroblasts / Q000378:metabolism; D006133:Growth Substances / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000494:pharmacology; D008214:Lymphocytes / Q000166:cytology; D009132:Muscles / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D010063:Ovum / Q000502:physiology; D011522:Protons; D012617:Sea Urchins; D012964:Sodium / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers; D013329:Structure-Activity Relationship
D002352:Carrier Proteins; D006133:Growth Substances; D007328:Insulin; D011522:Protons; D017923:Sodium-Hydrogen Exchangers; D000584:Amiloride; D012964:Sodium
L'échangeur Na+/H+ des cellules eucaryotes: propriétés biochimiques et pharmacologiques, rôle physiologique.