CORNEAL SYNTHESIS OF ALPHA-1-PROTEINASE INHIBITOR (ALPHA-1-ANTITRYPSIN)

Purpose. To determine if the cornea synthesizes alpha 1-proteinase inh ibitor (alpha 1-antitrypsin). Methods. Human corneas were placed in or gan culture for 24 hours in the presence of S-35-methionine to radiola bel corneal proteins. Monoclonal antibodies were used to precipitate l abeled alpha 1-proteinase inhibitor. The immunologically isolated inhi bitor was electrophoresed on polyacrylamide gels and visualized by aut oradiography or by staining for protein. Human corneas were also fixed with formalin and imbedded in paraffin. Sections were probed with H-3 -labeled complementary DNA probes to the coding region of alpha 1-prot einase inhibitor. Results. Metabolically labeled alpha 1-proteinase in hibitor was recovered from organ-cultured corneas and the cornea-condi tioned medium. Specific messenger RNA was observed in the cornea by in situ hybridization most prominently in corneal epithelial cells. Conc lusions. alpha 1-Proteinase inhibitor is synthesized and released by h uman corneal epithelial cells. These results indicate that the cornea has the ability to locally control degradation through synthesis of th is inhibitor without total dependence on a supply of the inhibitor fro m the vascular system.