[Effects of porcine pancreatic elastase-1 on the elastin in human trabecular meshwork--immunohistochemical studies:...

The aim of this study was to determine the localization of elastin and to estimate the influence of porcine pancreatic elastase-1 (PPE) and alpha 1-antitrypsin-elastase complex (alpha 1A-EL), a circulating form of PPE, on the elastin in human trabecular tissue. Trabecular tissues obtained from normal postmortem eyes and trabeculectomy specimens of primary open angle glaucoma (POAG) were used in this study. The tissues were embedded in Lowicryl K4M and sectioned for electron microscopy. Then the sections were subjected to protein A-gold immunohistochemical staining to determine the localization of elastin in the tissues. The sections were exposed to varying concentrations of PPE or alpha 1A-EL, before immunolabeling, to evaluate the density of the gold particles in the tissue. The gold particles were localized in the elastic fibers of normal and POAG specimens. The density of gold particles was reduced by relatively low concentrations of PPE and alpha 1A-EL in both normal and POAG specimens. These results suggest that elastin is localized in the elastic fibers of human trabecular tissues, and relatively low concentrations of PPE or alpha 1A-EL dissolve the elastin in the tissues.