Opacification of isolated rat lenses intoxicated with diethylmaleate: relation to lens membrane dysfunction.
We examined whether opacification of rat lenses treated with diethylmaleate (DEM), a depletor of reduced glutathione (GSH), is associated with membrane dysfunction. When isolated rat lenses were incubated with 2 mM DEM for 1, 6, and 24 h, a cortical opacity appeared at 6 h and was more pronounced at 24 h. This opacification was accompanied by decreases in GSH and vitamin E (Vit. E) content and Na+,K+-ATPase activity, and an increase in water content, but not by a change in the content of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation. Vit. E co-treatment caused a partial prevention of opacification, a complete recovery of decreased Vit. E content, attenuation of decreased Na+,K+-ATPase activity, and a decrease in TBARS content in rat lenses treated with 2 mM DEM for 24 h. Neither opacity formation nor changes in Vit. E, TBARS, and water content and Na+,K+-ATPase activity occurred in rat lenses treated for 48 h with 2 mM l-buthionine-(S,R)-sulfoximine, an inhibitor of glutathione synthesis, although a marked GSH depletion was observed. These results suggest that opacification of isolated rat lenses treated with DEM could be associated with impairment of Na+,K+-ATPase rather than GSH depletion.
Ohta
Y
Y
Department of Chemistry, School of Medicine, Fujita Health University, Toyoake, Japan. yohta@fujita-hu.ac.jp
Ito
A
A
Torii
H
H
D000818:Animals; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D002386:Cataract / Q000139:chemically induced* / Q000201:enzymology / Q000378:metabolism / Q000503:physiopathology*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D005978:Glutathione / Q000378:metabolism; D007908:Lens, Crystalline / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008298:Maleates / Q000633:toxicity*; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism / Q000494:pharmacology; D014867:Water
D008298:Maleates; D017392:Thiobarbituric Acid Reactive Substances; D014867:Water; D014810:Vitamin E; D019328:Buthionine Sulfoximine; D000254:Sodium-Potassium-Exchanging ATPase; C014476:diethyl maleate; D005978:Glutathione