Effects of selenium on ion homeostasis and transparency in cultured lenses.
Selenium toxicity was investigated in cultured rabbit lenses to provide further information about the role of Ca++ in Se cataract. At a dose of 0.1 mM for 20 hr, Se induces a 10% change in Na levels within 6 hr, a 30% increase after 20 hr, and a three-fold increase within 48 hr of subsequent culture after removal of Se. In contrast, Ca++ levels remained normal throughout the first 24 hr. Only a small, 25% decline in GSH was noted. Not until lenses begin to swell and become noticeably opaque and turbid were Ca++ levels found to be elevated. Thus, at 72 hr, 48 hr following the removal of selenium, Ca++ had increased to a concentration of 0.7 mM. Ca++ accumulation appears to be a consequence of osmotic stress rather than pump inhibition while Na accumulation is a direct consequence of Se-inhibited Na pump.
Hightower
K R
KR
Eye Research Institute, Oakland University, Rochester, Michigan 48309-4401.
McCready
J P
JP
D000818:Animals; D002118:Calcium / Q000378:metabolism; D046508:Culture Techniques; D005978:Glutathione / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects*; D007477:Ions; D007908:Lens, Crystalline / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009994:Osmolar Concentration; D010042:Ouabain / Q000494:pharmacology; D011817:Rabbits; D012643:Selenium / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism
D007477:Ions; D010042:Ouabain; D012964:Sodium; D005978:Glutathione; D012643:Selenium; D002118:Calcium