Abstract
Abstract: :
Purpose: To investigate possible protective effect of hepatocyte growth factor (HGF) against photoreceptor degeneration in rats. Methods: Eight–week–old Sprague–Dawley rats (SD, n=19) and 24–day–old Royal College of Surgeons (RCS, n=21) rats received intravitreal injections of HGF (10 µg) in the right eyes. The left eyes were injected with vehicle (heparin) and kept as control. Two days after the injection, SD rats were exposed to light of 3,000 lux for 72 hours. Gantzfeld electroretinograms (ERGs) were recorded under scotopic and photopic conditions at 14 days after the light damage in SD rats, and at 70 days of age in RCS rats. After ERG recordings, the rats were sacrificed for histological analysis. Results: In the HGF–treated eyes of light–damaged SD rats, the thresholds of the scotopic and photopic b–waves were 3.30 ± 1.11 (mean ± SD) and 1.31 ± 0.52 log cd/m2 lower, respectively, than in the control eyes (p<0.01). The maximum amplitudes of the scotopic and photopic b–waves of HGF–treated eyes of SD rats were significantly larger than those of the control eyes (p<0.0005). In the HGF–treated eyes of RCS rats, the thresholds of the scotopic and photopic b–waves were 1.50 ± 0.83 and 0.82 ± 0.19 log cd/m2 lower than in the control eyes (p<0.05 and p<0.0001, respectively), and the maximum amplitudes of the scotopic and photopic b–waves of HGF–treated eyes were significantly larger than those of the control eyes (p<0.0005). The functional results of the treated eyes at 70 days of age were equivalent to those of 42–day–old RCS rats. The treated eyes had significantly large number of rods and cones compared to the control in either light–damaged SD or RCS rats (p<0.0005). Conclusions: HGF provided structural and functional preservation of rods and cones in rats with photoreceptor degeneration that was induced by environmental stress and gene mutation.
Keywords: photoreceptors • electroretinography: non–clinical • retinal degenerations: hereditary