Session Title: FP-14 Vascular Diseases and Diabetic Retinopathy IV
Session Date/Time: Saturday 13/09/2014 | 16:30-18:00
Paper Time: 17:50
Venue: Boulevard F
First Author: : O.Dorokhova UKRAINE
Co Author(s): : E. Maltsev O. Zborovska
To compare state of the retinal pigment epithelium (RPE) at dithizone diabetes mellitus (DM) model in rabbits with streptozotocin DM in rats and mice.
The Filatov Institute of Eye Diseases and Tissue Therapy, NAMS Ukraine, Ukraine, Odessa.
We modelled moderate diabetes in 8 Chinchilla rabbits by using dithizone, in 8 rats (Vistar) and 8 mice (CBA/C57B1xK/F1) by using streptozotocine. Observing animals did not exceed 6 months. Enucleated eyes were studied by histological methods.
There were not significant retinal changes at all stages of observation in the rats and mice retinas. However histological picture of the rabbits eyes was quite different. RPE was normal at persistent hyperglycemia secondary phase (33 - 36 hours after injection of dithizone). But we determine significant destructive changes of RPE in 16-17 weeks. Changes were not the same in different parts of the retina, and the degree of RPE changes didn’t correlate with the depth of neurodestructive changes in sensory retina in the same places of histologic specimen. In some retinal parts RPE was better preserved, with almost normal appearance. In others parts it was modified intensely, flattened, depigmented or absent. Sometimes cells were oedematose, increased in size, but contain of pigment granules, and cells were shifted in the photoreceptor layer. RPE might persist normal in such places of retina where neurogenertive changes were apparent. And, on the contrary, be hard where neurogenertive changes were mild or even absent. Of course, there were such areas of retinal damage where destruction of RPE and sensory retina were present simultaneously.
We suggested that such pronounced destructive RPE changes in rabbit retina, may be consequence of the negative effect of metabolic changes in the retina caused by diabetes, on the one hand. And, on the other hand, may be the direct chelating dithizone effect on the element zinc in retina and choroid of the eye. We also suggest to use this retinopathy model not only for investigating diabetic neurodegenerative changes and its treatment, but for investigating pharmacological correction of retinal degenerative diseases that affects RPE (such as AMD, or retinitis pigmentosa).