Effects of mitomycin C on the expression of chymase and mast cells in the conjunctival scar of a monkey trabeculectomy model.
OBJECTIVE
To determine the effects of mitomycin C (MMC) on the expression of chymase and mast cells in the conjunctival scar after trabeculectomy.


METHODS
Ten eyes of five monkeys were used. Three eyes underwent trabeculectomy with MMC (MMC-treated), four eyes had trabeculectomy without MMC (placebo-treated), and three eyes served as control eyes. Intraocular pressure was measured before and three weeks after surgery. The scores of the degree of conjunctival adhesion were evaluated. Immunohistochemistry was used to analyze the densities of proliferative cell nuclear antigen-positive cells, chymase-positive cells, and mast cells. The ratio of collagen fiber areas to conjunctival and scleral lesions was analyzed by Mallory-Azan staining.


RESULTS
After trabeculectomy, the intraocular pressure reduction of MMC-treated eyes was significantly different from placebo-treated and control eyes (p=0.032, 0.035). The adhesion score of MMC-treated eyes was also significantly lower than that of placebo-treated eyes (p=0.034). Densities of proliferative cell nuclear antigen-positive cells, chymase-positive cells, and areas of collagen fiber in conjunctival and scleral lesions were significantly decreased in MMC-treated eyes, compared with placebo-treated eyes (p=0.034, 0.034, 0.049, respectively). There was a tendency for the density of mast cells to be suppressed in MMC-treated eyes (p=0.157).


CONCLUSIONS
Chymase might be involved in one of the mechanisms by which MMC suppresses scar formation after trabeculectomy.
Department of Ophthalmology, Takatsuki Red Cross Hospital, Osaka, Japan.
Kouhei
K
Okada
Tetsuya
T
Sugiyama
Shinji
S
Takai
Denan
D
Jin
Osamu
O
Ishida
Masanori
M
Fukmoto
Hidehiro
H
Oku
Mizuo
M
Miyazaki
Tsunehiko
T
Ikeda
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D053818:Chymases / Q000378:metabolism*; D002921:Cicatrix / Q000201:enzymology / Q000473:pathology* / Q000503:physiopathology; D003228:Conjunctiva / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D024022:Fibrillar Collagens / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D000882:Haplorhini; D007150:Immunohistochemistry; D007429:Intraocular Pressure / Q000187:drug effects; D008407:Mast Cells / Q000187:drug effects*; D016685:Mitomycin / Q000494:pharmacology*; D023421:Models, Animal; D010919:Placebos; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D014130:Trabeculectomy
D024022:Fibrillar Collagens; D010919:Placebos; D018809:Proliferating Cell Nuclear Antigen; D016685:Mitomycin; D053818:Chymases