A study on lipid peroxide-induced lens damage in vitro.
The effects of linolenic acid hydroperoxide (LAPO) on isolated rat lenses were investigated, because they are believed to be cataractogenic in vivo. They were also compared with the effect of linolenic acid (LA), source of LAPO. Rat lenses, which were exposed for 5 hr to either 210 microM or 420 microM LAPO, became cloudy and this change was associated with increases in the level of malondialdehyde (MDA), a breakdown product of lipid peroxide, and decreases in non-protein thiol (NP-SH) content. Concomitantly, there were changes in cation contents: Na+ and Ca2+ were increased whereas K+ and Mg2+ were decreased. The changes in the levels of the above parameters, correlated with the concentration and the treatment time of LAPO to which the lenses were exposed. The increase of MDA was 2-4-fold over normal level and was consistent with those in cataractous lenses of the human and experimental animal models. On the other hand, if the lenses were exposed to LA, the only change observed was a small alteration of cationic content. If the lenses were cultured for an additional 24 hr in the absence of either LA or LAPO, the cation content continued to change only in those lenses which were previously exposed to LAPO. These results show that at concentrations of lipid peroxides, which are associated with the development of cataract in the human and animal models, there are changes in vitro in cation content, MDA and NP-SH levels, which accompany the development of a lens opacity.
Mibu
H
H
Central Research Laboratories, Santen Pharmaceutical Co., Ltd., Osaka, Japan.
Nagata
M
M
Hikida
M
M
D000818:Animals; D002118:Calcium / Q000032:analysis; D002386:Cataract / Q000139:chemically induced*; D006801:Humans; D066298:In Vitro Techniques; D007908:Lens, Crystalline / Q000737:chemistry / Q000187:drug effects; D008042:Linolenic Acids / Q000633:toxicity*; D008054:Lipid Peroxides / Q000633:toxicity*; D008274:Magnesium / Q000032:analysis; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D011188:Potassium / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000032:analysis; D013438:Sulfhydryl Compounds / Q000032:analysis; D013997:Time Factors; D017962:alpha-Linolenic Acid / Q000633:toxicity
D008042:Linolenic Acids; D008054:Lipid Peroxides; D013438:Sulfhydryl Compounds; D017962:alpha-Linolenic Acid; C025998:13-hydroperoxylinolenic acid; D008315:Malondialdehyde; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium