Purchase this article with an account.
P. Geisen, J.R. McColm, M.E. Hartnett; Retinal cell injury in a rat model of retinopathy of prematurity . Invest. Ophthalmol. Vis. Sci. 2004;45(13):737.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To investigate retinal cell injury associated with oxygen fluctuations in a rat model of ROP Methods: Newborn rats were exposed to variable oxygen levels (50% 24 hrs, 10% 24 hrs, repeated cycling). On day 7 and 14, retinas were dissected and wholemounted. They were then either i) stained with activated caspase–3 and propidium iodide to measure apoptosis and nucleated cells or ii) further dissected at the vascular/avascular interface and the separated sections homogenized for lipid hydroperoxides (LHP) measurement. The stained retinas were imaged using laser scanning confocal microscopy. 12 random images of the inner nuclear layer (INL) were taken and caspase positive or condensed nuclei were counted. Number of cells stained per area imaged in each retina (0.22 mm2) were averaged. Controls were age matched room air (RA) raised pups Results:At P7, apoptotic (caspase–3 positive) and cells with condensed nuclei (PI stain) in the INL were not significantly greater in RA than in fluctuating oxygen groups (36 vs 22; 83 vs 61); however, at P14, the number of apoptotic cells and dying cells were greater in the fluctuating oxygen than RA groups (14 vs 0, 77 vs 29 respectively, p<0.05, students T–Test, n=15 experimental, n=3 control). This effect appeared mainly to be a persistence of apoptotic and PI positive cells in the fluctuating oxygen group.At P7 and 14 LHP were detectable in both vascular (v) and avascular areas (a) (P7 v=15.1µM; a=13.6µM: P14 v=31.7µM; a=20.5µM, n=5). These differences were not significant between areas or between P7 and P14, however there was a trend to higher LHP in the older pups. Controls at both ages were fully vascularized with levels at 4.9µM in P7 and 39.2µM in P14 Conclusions: Fluctuations in oxygen within the range that occurs in preterm infants with severe ROP leads to tissue damage determined as increased LHP and apoptosis. The time course supports LHP production occurring before cell death in the INL
This PDF is available to Subscribers Only