S Cunningham1, J R McColm, J Wade, K Sedowofia, N McIntosh, B Fleck. 1. Child Life and Health, Reproductive and Developmental Sciences, University of Edinburgh. Princess Alexandra Eye Pavilion, Edinburgh, Scotland, United Kingdom.
Abstract
PURPOSE: To examine changes in the retinal vasculature of rat pups after 14 days of minute-by-minute small variations in oxygen. METHODS: Arterial oxygen data from a preterm infant who developed severe retinopathy of prematurity (ROP) was translated to equivalent values for the rat. Newborn rat pups were raised for 14 days in a cage in which a computer controlled the atmosphere to mimic the fluctuating oxygen profile (group V). Positive controls (P) of 12-hour cycles of 80% and 21% were run concurrently, as were room air controls (C). All were killed at day 14. RESULTS: Groups V and P had significantly larger avascular retinal areas than C [median, interquartile range (IQR) 1.7%, 0-7.9%; 10%, 8.1-13%; 0%, 0-0%, respectively; each group n = 30]. Group P had a higher capillary branch count than C (median, IQR: 310/mm(2); 253-311 mm(2); versus 277/mm(2), 272-364/mm(2), respectively), but this was not significant using a multilevel analysis. Group V had significantly reduced capillary counts compared with C (median, 261/mm(2); IQR, 215-290/mm(2); P < 0.05 multilevel analysis). No neovascularization was seen in any group, though abnormal terminal vessels were seen at the avascular/vascular retina interface in 73% of rats in group P and 21% of rats in group V. In situ hybridization on serial sections demonstrated VEGF in the inner nuclear layer of the retina in P and V, whereas C showed trace levels only. CONCLUSIONS: The vaso-obliterative stage of ROP can be induced in rats using clinically relevant oxygen levels.
PURPOSE: To examine changes in the retinal vasculature of rat pups after 14 days of minute-by-minute small variations in oxygen. METHODS: Arterial oxygen data from a preterm infant who developed severe retinopathy of prematurity (ROP) was translated to equivalent values for the rat. Newborn rat pups were raised for 14 days in a cage in which a computer controlled the atmosphere to mimic the fluctuating oxygen profile (group V). Positive controls (P) of 12-hour cycles of 80% and 21% were run concurrently, as were room air controls (C). All were killed at day 14. RESULTS: Groups V and P had significantly larger avascular retinal areas than C [median, interquartile range (IQR) 1.7%, 0-7.9%; 10%, 8.1-13%; 0%, 0-0%, respectively; each group n = 30]. Group P had a higher capillary branch count than C (median, IQR: 310/mm(2); 253-311 mm(2); versus 277/mm(2), 272-364/mm(2), respectively), but this was not significant using a multilevel analysis. Group V had significantly reduced capillary counts compared with C (median, 261/mm(2); IQR, 215-290/mm(2); P < 0.05 multilevel analysis). No neovascularization was seen in any group, though abnormal terminal vessels were seen at the avascular/vascular retina interface in 73% of rats in group P and 21% of rats in group V. In situ hybridization on serial sections demonstrated VEGF in the inner nuclear layer of the retina in P and V, whereas C showed trace levels only. CONCLUSIONS: The vaso-obliterative stage of ROP can be induced in rats using clinically relevant oxygen levels.
Authors: Ryan W Bavis; Alexandra H Millström; Song M Kim; Carolyn A MacDonald; Caitlin A O'Toole; Kendra Asklof; Amy B McDonough Journal: Respir Physiol Neurobiol Date: 2018-11-12 Impact factor: 1.931
Authors: James D Akula; Julie A Mocko; Anne Moskowitz; Ronald M Hansen; Anne B Fulton Journal: Invest Ophthalmol Vis Sci Date: 2007-12 Impact factor: 4.799