Abstract
Abstract: :
Purpose: The neuroprotective effect of erythropoietin (EPO) is now well established but this hematopoietic growth factor can also induce the release of neurotransmitters and so directly or indirectly influence neurotransmission. In order to assess the possible toxicity of EPO on retinal tissue, we investigated its effect on the retina electrophysiological function. Methods: Retinas from Wistar rats (250–300 g) were isolated and kept in a perfusion chamber under dim red light. Every 5 minutes, stimulation by a white light flash (300 lux, 1 ms) allowed to record electroretinograms (ERG). Epoetin alpha, the recombinant human form of EPO, was injected into the perfusion solution at a concentration of 80 UI/mL when the ERG b–wave becomes stable. ERGs were recorded during 5 hours after the injection and the b–wave amplitude was measured. Results: After EPO was applied to the retinas (n = 6), the b–wave amplitude curve versus time was the same as control ones (n = 6). At the studied concentration of 80 UI/mL, no statistical difference was shown neither on the b–wave amplitude evolution versus time nor on the retina survival length. It seems that a second concentration we tested (20 UI/mL) does not have any effect either. Conclusions: We showed no direct effect of high doses of EPO on the ERGs obtained from isolated rat retinas. Moreover, it is known now that EPO has a protective influence on apoptosis, inflammation and oxidation, all of them capable of damaging the retina. Thus EPO could be used to improve their deleterious consequences without any toxic effect on vision.
Keywords: retina • electroretinography: non–clinical • drug toxicity/drug effects