Effects of electroacupuncture on retinal nerve growth factor and brain-derived neurotrophic factor expression in a rat model of retinitis pigmentosa

The aim of this study was to investigate the effect of electroacupuncture (EA) on the progression of retinal degeneration in rats affected by inherited retinitis pigmentosa (IRP) and to correlate this event with the retinal expression of neurotrophins. Thirty-day-old Royal College of Surgeons (RCS) rats were exposed to 25-min-long daily sessions of low-frequency EA for 11 consecutive days. Control-untreated and EA-treated rats were sacrificed 1 h after the last EA session, and their retina removed for biochemical, molecular, and immunohistochemical analyses. Our data revealed that daily sessions of low-frequency EA for 11 days to RCS rats during a critical developmental stage of retinal cell degeneration cause an increase of retinal nerve growth factor (NGF) and NGF high-affinity receptor (TrkA) expression; and increase of outer nuclear layer (ONL) thickness; and enhanced vascularization. These findings suggest the possible beneficial effects of EA treatment in the development of IRP-like retinal degeneration of RCS rats and that the mechanism through which EA might exerts its action on the regulation of NGF and brain-derived neurotrophic factor (BDNF) and/or their receptors in retinal cells.