ATPases and lens ion balance.
In the lens, different cells appear to be specialized such that some have a high capacity for energy-dependent ion transport while others do not. This short review describes the distribution of functional Na,K-ATPase activity and Ca-ATPase activity in the lens. Movement of ions in the extracellular space between lens fibers, a topic studied by David Maurice 25 years ago, is discussed together with cell-to-cell movement of ions which is facilitated by extensive coupling in the lens cell mass. The expression of different Na,K-ATPase and Ca-ATPase isoforms in lens epithelium and fiber cells is considered along with mechanisms that potentially regulate the activity of these transport proteins.
Paterson
Christopher A
CA
Department of Ophthalmology and Visual Sciences, University of Louisville, School of Medicine, Louisville, KY 40202, USA. cpater@aol.com
Delamere
Nicholas A
NA
D000251:Adenosine Triphosphatases / Q000502:physiology*; D001693:Biological Transport, Active / Q000502:physiology; D000252:Calcium-Transporting ATPases / Q000502:physiology; D002386:Cataract / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology; D006801:Humans; D017136:Ion Transport / Q000502:physiology; D007908:Lens, Crystalline / Q000201:enzymology* / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology
D000251:Adenosine Triphosphatases; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase