The effects of D-penicillamine on a murine model of oxygen-induced retinopathy

Purpose To determine the effect of intraperitoneal and intravitreal D-penicillamine (DPA) on retinal neovascularization in a murine model of oxygen-induced retinopathy. Methods On postnatal day 7, 16 mice were injected intraperitoneally with 300 mg/kg/day DPA for 3 days followed by 50 mg/kg/day for 7 days. A different group of 7 mice were injected intraperitoneally with 600 mg/kg/day DPA for 3 days followed by 100 mg/kg/day for 7 days. A third group of 14 mice were injected with 1,500 mg/kg/day DPA for 2 days; a control cohort of 17 mice received intraperitoneal phosphate-buffered saline (PBS). An additional 15 mice underwent intravitreal injection of 1 μL of 100 mg/mL DPA in the right eye and 1 μL PBS intravitreally in the left eye as a control. All groups were placed in a 75% oxygen chamber for 7 days then room air for 3 days before being sacrificed and enucleated. The retinas were stained and flat-mounted to determine the severity of retinal neovascularization by quantifying neovascular buds. Results After intraperitoneal injection, the mean number of glomeruli and tubules was similar in the DPA and PBS groups ( P = 1.0), regardless of DPA dosage. The dosage of 1,500 mg/kg/day proved to be uniformly lethal. After intravitreal injections, the mean number of glomeruli ( P  = 0.16) and tubules ( P = 0.7) were similar in the DPA and PBS groups. Conclusions Neither intraperitoneal nor intravitreal injection of DPA inhibits retinal neovascularization in a murine model of oxygen-induced retinopathy.