HISTOCHEMICAL-STUDY OF LEUKOCYTE ELASTASE ACTIVITY IN ALKALI-BURNED RABBIT CORNEA

In order to contribute to a better understanding of the role of leukoc yte elastase in corneal melting after a severe alkali burn, the in sit u appearance and activity of this enzyme in the rabbit cornea was-exam ined, For this reason, a histochemical approach using cryostat section s on membranes and a gel incubation medium with the very sensitive sub strate -Ala-Ala-Pro-Val-7-amino-4-trifluoromethylcoumarin (Enzyme Syst ems Products, Livermore, Calif,, USA) was employed. In contrast to the normal rabbit cornea where leukocyte elastase activity was absent, in alkali-burned cornea a high enzyme activity in inflammatory cells (pa rticularly polymorphonuclear leukocytes) was present, The extracellula r release of leukocyte elastase into the substantia propria of the cor neal stroma was associated with disintegration of the corneal stroma a nd the appearance of corneal ulcers, These results show that leukocyte elastase is associated with corneal destruction after a severe alkali burn.