Purchase this article with an account.
Bruce A. Berkowitz, David Bissig, Timothy S. Kern, Robin Roberts; Robust Diabetes-induced Retinal Thickening in Male Sprague Dawley Rats In Vivo: Inhibition by Angiotensin Converting Enzyme Inhibition (ACEi) Treatment. Invest. Ophthalmol. Vis. Sci. 2011;52(14):3555. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
High resolution MRI has documented retinal thickening in 3 mo diabetic male Sprague Dawley rats in vivo (IOVS,48:10, 4753). In this study, we characterized the time course of this supernormal retinal thickness and whether or not this thickening is normalized by ACEi treatment.
In diabetic and age-matched nondiabetic male Sprague Dawley rats with and without treatment of the ACEi enalapril (mean range 5-7 mg/Kg, drinking water) central retinal thicknesses were measured from MRI (25 um) between 2 and 9 mo of diabetes. A subset of rats was chronically instrumented to allow for radiotelemetry readout of central blood pressure (BP) and heart rate (HR). Glycated hemoglobin and retinal thickness ex vivo (histology) were also collected.
Between 2 and 9 mo of diabetes, untreated rats had significantly (P < 0.05) thicker (avg. 15%) central retina in vivo than normoglycemic controls; thickening was not demonstrated on histology after fixation and dehydration. Enalapril normalized retinal thickness in vivo after 5 mo, but not 3 mo, of treatment. Relative to nondiabetic controls, HR and BP were subnormal in diabetic enalapril-treated rats, which were similar to diabetic rats.
A surprisingly sustained retinal thickening in diabetic male Sprague Dawley rats in vivo was found on high resolution MRI examination; ACEi treatment corrected this supernormal thickness. Since our previous MRI data did not detect increase passive leakage through blood-retinal barrier until 8 mo of diabetes in this model, the present findings raise the possibility that the present retinal thickening is due, at least initially, to cytotoxic (as opposed to vasogenic) edema.
This PDF is available to Subscribers Only