Abstract
Abstract: :
Purpose: To examine the expression of Heat shock proteins (Hsps) in the optic nerve head of experimental primate glaucomatous eyes. Methods: The experimental glaucoma was induced by repeated argon laser photocoagulation to the chamber angle of 3 adult monkeys. After 3-4months duration of glaucoma, the advanced optic disc cupping was recognized. The monkeys were sacrificed by overdose of ketamine and pentobarbitrate injection and eyes were gently enucleated. Both experimental and control eyes were fixed in 4% paraform aldehyde and processed for paraffin embedding. Four microns thick sections were prepared. Panels of antibodies against heat shock proteins including anti-hsp 90, 70, 60, 47 and 27 were used for the immunostaining (Santa Cruz, CA, USA). Labeled streptavidin-biotin method was used (LSAB kit, DAKO). For quantitative evaluation of intensity of immunohistostaining, the measurements were made as the optical density (OD) of the light source of light microscope, with the DAB analysis system (Carl Zeiss, Germany). Grouped Student t tests were used for statistical analysis. Results: In morphological study, all experimental glaucoma eyes showed typical advanced glaucomatous optic neuropathy. The intensity of immunostaining for Hsp 70, 47 and 27 were enhanced at the lamina cribrosa of the glaucoma eyes compare to normal eyes (p<0.01). In post lamina regions, the staining of each Hsps of glaucoma eyes was decreased. (p<0.01). Conclusions: Intraocular pressure elevation may affect expression of Hsps on optic nerve head particularly at lamina cribrosa. Enhanced Hsps especially HSP 47 may be associated with the remodeling processes of glaucomatous optic neuropathy.
Keywords: optic disc • immunohistochemistry