OBJECTIVETo investigate the effect of recombinant human erythropoietin (rhEPO) on the expression of bcl-2 protein in the retina of rabbits with acute high intraocular pressure and explore the mechanism underlying the protective effect of rhEPO on the retina against ischemia-reperfusion injury.

METHODSrhEPO was injected subcutaneously in the ear of a rabbit model of acute high intraocular pressure induced by physiological saline perfusion into the anterior chamber. Bcl-2 protein expression in the retina of the rabbits was observed by immunohistochemical staining on days 1, 3, 7, and 14 after retinal ischemia-reperfusion and compared with that in normal rabbits and untreated rabbit models.

RESULTSbcl-2-positive cells were observed in the retina of normal rabbits with a mean positive cell number of 10.5-/+1.2 in each high-power visual field. Compared with that in the normal control group, the number of the positive cells decreased significantly in both the model group and EPO group (P<0.05, P<0.01), but the latter group showed a significantly greater number than the former (P<0.05 at day 7 and P<0.01 at day 14).

CONCLUSIONSystemic administration of rhEPO can up-regulate the expression of bcl-2 protein in the retina of rabbits with acute high intraocular pressure, which is probably one of the mechanisms for the protective effect of rhEPO on the retina against ischemia-reperfusion injury.