The Effect of MMC on Chick Lens and its Mechanism.

Park, Hyun Kyung; Lee, Kwang Won; Yim, Hye Bin; Joo, Choun Ki

Original Article

Journal of the Korean Ophthalmological Society 2000;41(11):2427-2436.
Published online November 1, 2000.

The Effect of MMC on Chick Lens and its Mechanism.

Hyun Kyung Park, Kwang Won Lee, Hye Bin Yim, Choun Ki Joo

Department of Ophthalmology, Kangnam St. Mary's Hospital, College of Medicine, The Catholic University of Korea, #505 Banpo-dong, Seocho-ku, Seoul, 137-701, Korea. ckjoo@cmc.cuk.ac.kr

기관배양에서 Mitomycin C 가 수정체에 미치는 영향과 기전

박현경(Hyun Kyung Park),이광원(Kwang Won Lee),임혜빈(Hye Bin Yim),주천기(Choun Ki Joo)

Abstract

Mitomycin C (MMC)is used in trabeculectomy to promote the intraocular pressure control, but at the same time it also seems to increase the risk of cataract. In this study, we investigated the mechanism by which MMC causes lens opacity.The whole lenses were extracted from fertilized eggs of 11~13 days and cultured in M199 media supplemented with fetal bovine serum (FBS)at 38 degrees C.Levels of Lipid peroxidation (LPO)and Glutathione (GSH)were measured 24 hours and 5 minutes after treatment with 1 mg/ml MMC for 5 minutes.Changes of lenses by MMC were examined by light microscopy, and the modification of lens proteins was analyzed by SDS-PAGE and size exclusion column. Lens opacity was induced by MMC treatment in concentration of 1 mg/ml for 5 min, and MMC treated lenses showed 3 times higher LPO level and 2 times lower GSH level than normal lenses.In ultrastructure of opaque lenses, many vacuole formations in cortical area near equatorial zone were found.In electrophoresis followed by silver staining and size exclusion column profile, high molecular weight formation of lens proteins by MMC treatment was mainly due to disulfide bond.Also, when we treated the lens with antioxidants, the extent of opacity was decreased. In this study, we demonstrated that lenses treated with MMC became opaque mainly due to oxidative stress resulting in HMW formation of lens proteins by disulfide formation as well as irreversible oxidation.

Key Words: Glutathione (GSH);Lens;Lipid peroxidation (LPO);Mitomycin C (MMC);Oxidative stress