Purchase this article with an account.
Z. Yaqoob, L. Sharp, K. Sedowofia, J.C. Wade, J.R. McColm, D.R. Giles, B. Fleck, S. Cunningham, N. McIntosh; Retinal Pericyte/Smooth Muscle Cell Coverage in Rats Exposed to a Variable Oxygen Model of Retinopathy of Prematurity (Edinburgh Model) . Invest. Ophthalmol. Vis. Sci. 2003;44(13):585.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:To investigate pericyte/smooth muscle cell coverage during development of the normal rat retinal vasculature and determine how it is affected by fluctuating oxygen. Methods:Litters of newborn rats were either reared in room air or exposed to a minute-by-minute variable oxygen profile, which induces features of retinopathy (including peripheral avascularity, vascular immaturity and abnormal terminal vessels) for 2, 7 and 14 days. Following sacrifice, the eyes were enucleated. The right eyes were fixed and retinal wholemounts prepared. The endothelial cells were visualised using G.simplicifolia (Bandeiraea) isolectin B4 and the pericytes/smooth muscle cells with α-smooth muscle actin (α-SMA) or desmin. The vasculature was examined using a confocal microscope. The left retinas of each litter were pooled, the protein extracted and blotted for α-SMA. Results:In the normal rat retina, at day 2 α-SMA positive cells were found only on the arterioles. By day 7, coverage had begun on the arterial capillaries, and progressed further by day 14. Desmin positive cells, however, were present across the whole retinal vasculature, including the developing peripheral edge on all timepoints examined. Occasionally, cells were identified positive for both α-SMA and desmin. This pattern of labelling was also observed in retinas of rats exposed to variable oxygen. However, the retinal development in these rats was delayed and the longitudinal coverage of the arterioles with α-SMA positive cells does not progress as far as in controls. Desmin staining, although seen at the leading edge of the developing vasculature, was also reduced, particularly on the arterioles. Western blot analysis confirmed the decrease in α-SMA expression on days 7 and 14. Conclusions:α-SMA stains smooth muscle cells; desmin stains pericytes. In normal development pericyte coverage is very rapid, but smooth muscle cell coverage lags significantly behind vessel formation. Smooth muscle cell coverage of the retinal vessels is decreased in rats exposed to variable oxygen in the Edinburgh model of retinopathy of prematurity.
This PDF is available to Subscribers Only