PROTECTION AGAINST LIGHT-INDUCED RETINAL DEGENERATION WITH NAFTIDROFURYL (PRAXILENE) IN THE RAT

The purpose of this work was to investigate the ability of Naftidrofur yl (Praxilene, Lipha-Sante, France) to produce light-induced retinal d egeneration in the rat. Fisher male rats were injected intraperitoneal ly with 30 mg/kg Naftidrofuryl in 0.9% NaCl. The first injection took place 30 minutes before the beginning of the constant light exposure ( 90 fc) and was repeated at days 2 and 4. The animals were sacrificed a t day 7. Controls treated or not with Naftidrofuryl were exposed to a regular cyclic light environment (20 fc). Eyes were fixed in 4% parafo rmaldehyde and embedded in Historesin. Whole median 5 mu m sections of the retina were analyzed by measurement of the thickness of the retin al photoreceptor nuclear and inner and outer segment layers with a Bio com image analyzer. After one week of constant illumination, the photo receptor nuclear layer thickness decreased in all regions of the retin a, more in the superior than in the inferior region. In animals treate d with Naftidrofuryl, a significant rescue from degeneration was obser ved throughout all retinal regions. An average rescue of 66% (compared with the retina from constantly illuminated rats) was observed. Nafti drofuryl had no effect on cyclic light-raised rats. Naftidrofuryl part ially protects against the degeneration of photoreceptors induced by c onstant light illumination of the rat retina.