Abstract
Abstract: :
Purpose: To evaluate the effect of estrogen on survival of retinal ganglion cells (RGCs) after transient retinal ischemia–reperfusion (RIR) in rats. Methods: Retinal ischemia was induced in 60 ovariectomized adult rats by increasing introcular pressure (IOP) to 100mmHg for 60 minutes via an intracameral catheter. 17ß–estradiol (100µg/kg) or physiological saline was injected into the 60 rats subcutaneous, in a random way, two hours before IOP was increased. The retinas were collected at 0, 12, 24, 48 and 72h respectively after reperfusion. The density of RGCs was examined with HE staining. Cell death of retina was assayed by TdT–mediated biotin–dUTP nick end labeling (TUNEL) and the mRNA expression level of bcl–2, bax and caspase–3 was determined by real–time fluorescent quantitative reverse transcription polymerase chain reaction (RT–PCR). Results: In 17ß–estradiol–treated rats after RIR, compare with control rats, the cells in retinal ganglion layer were higher (P<0.05); the TUNEL positive cells were much less at 24h and 48h (P<0.05), Bcl–2 mRNA increased and reached the peak at 24h (P<0.05) while bax and caspase–3 mRNA decreased at all time points (P<0.05). Conclusions: Estrogen may protect retinal neurons from transient ischemia–reperfusion injury in ovariectomized rats.
Keywords: neuroprotection • intraocular pressure • ischemia