Experimental Study for Rabbit Corneal Epithelial Toxicity of MMC

ABSTRACT

We studied the biological effects of Mitomycin C(MMC) in cellular metabolic activity and cytotoxicity on the corneal epithelial cell in rabbit that is clinically used according to MMC concentrations and exposure time. The concentration of MMC were 0.01%, 0.02%, 0.04%, 0.06%, 0.1%, and exposure time were 5, 10, and 30 minutes. MTT assay (3-I4,5-Dimethy-lthiazol-2-ylI-2,5-diphenyltetrazolium bromide) and transmission electromicroscopic examination were performed to access the metabolic activity of corneal cell, toxicity of corneal epithelial cell, and cellular morphology. In calorimetric assay, the higher the concentration of MMC and longer the duration of exposure time, the cellular metabolic activity was decreased. Also the toxicity of corneal epithelial cell was increased in a concentration and time dependent manner. The metabolic activity of corneal cell were inhibited by 50% at least over MMC 0.04% for 30 minutes exposure time. The LD50 at 5 minutes exposure was MMC 0.057%. In histologic finding, the higher the concentration of MMC, the change of cellular structure such as loss of microvilli, enlargement of rough endoplasmic reticulum or mitochondria, damage of nuclear membrane were more appeared. To obtain the efficacy of MMC for inhibition of cellular proliferation, we think that further experimental and clinical studies should be need to assess the safe concentration and exposure time of MMC to the corneal toxicity.