Abstract
Purpose::
Basic fibrobroblast growth factor ( bFGF )has neurotrophic effects in vitro and in vivo .It has been shown to rescue photoreceptoe cells in rats exposed in costant light and in the RCS rat a model with a genetic defect of RPE that impairs outer segment phagocitosis ,but the effects of intravitreous injection of bFGF in mice are equivocal.The purpose of the persent study was to determine whether intravitreal injection of bFGF would have similar survaival effect on photoreceptor cells death in B6(A)-Rpe65rd12 /J (Retinitis pigmentosa) mice.
Methods::
This study included 40 eyes of 20 mice model B6(A)-Rpe65rd12/J from The Jackson Laboratories (Bar Harbor, Maine, Usa), mean age 12 weeks and female and weighing between 25 - 30 g.Mice present in chromosome 3 spontaneuos mutation of gene Rpe65.The phenotype expression of this mutation is retinal degeneration like human retinitis pigmentosa. This mutant mouse loses photoreceptor cell slowly over many month . The bFGF was recombinant Human Fibroblast Growth Factor -basic from Biosouce ( Caramillo, Usa ).In the present study bFGF( 1 µg / 1µl PBS) was injected intravitreally into mice at age 12 week; 1 eye received bFGF/PBS , the controlateral eye recivedan injection of PBS .Mice were killed 4 weeks following the injection and the eyes were processed for histology and immunohistochemistry and Electron Microscopy .
Results::
Hystological findings showed minimal differnces between treated and not treated tissue. Electron microscopy showed that the intravitreous injection of bFGF have survaival effect on photoreceptor cells death . Infact not treated tissue showed outer segment of rods distoerted severely shortenedor or absent and many autofagic vacuoles are seen in the perinuclear cytoplasml and swollen mitohondria. Treated tissue with bFGF showed free melanin granules in the far periphery and outer segment of rods lightly distorted and no many autofagic vacuoles . The ultrastructural study has been shown that injection of bFGF have survaival effect on photoreceptor cells death.
Conclusions::
The intravitreous injection of bFGF mice model B6(A)-Rpe65rd12/J have survaival effect on photoreceptor cells death .
Keywords: growth factors/growth factor receptors • retinal degenerations: cell biology • apoptosis/cell death