Comparative toxicity of mitomycin C and 5-fluorouracil in vitro.

The adjunctive use of antimetabolites has revolutionized surgical procedures to correct glaucoma in the past decade. Although much is known about the in vitro and in vivo actions of 5-fluorouracil and mitomycin C, their use in the eye has raised new questions about cellular toxicity. For example, filtering blebs after a surgical procedure supplemented with mitomycin C are relatively avascular in comparison with those seen with 5-fluorouracil supplementation. We investigated the effect of 5-fluorouracil and mitomycin C on cultured capillary endothelial cells and fibroblasts. The viability and morphologic characteristics of 3T3 fibroblasts and capillary endothelial cells were studied in light of increasing doses of 5-fluorouracil and mitomycin. Both cell types showed similar sensitivity to mitomycin C. However, fibroblasts were far more sensitive to 5-fluorouracil than were the cultured microvascular endothelial cells. Thus 5-fluorouracil appears to be toxic to fibroblasts while sparing vascular endothelial cells, whereas mitomycin C is cytotoxic for both cell types.