Abstract
Abstract: :
Purpose: Nilvadipine, a dihydropyridine-type calcium channel blocker, is fat soluble and passes through the blood:brain barrier easily. It is a therapeutic drug for hypertension and ischemic cerebrovascular disease. It has been reported in glaucoma that calcium blockers can protect retinal ganglion cells (RGCs). The purpose of this study was to determine whether nilvadipine will protect the retina against ischemia-reperfusion injury in rats. Methods: Eight week-old Wister rats (200 g) were anesthetized with pentobarbital sodium. Initially, 0.3 ml nilvadipine (0.5 mg/ml in polyethylene glycol 400) was injected intramusculary. Control rats received the same amount of polyethylene glycol 400. Ten minutes after the injection, the anterior chamber was cannulated and the intraocular pressure was increased to 120 mmHg and maintained for 45 minutes. During the pressure elevation, the body temperature was kept at 37° C. Before and 7 days after the ischemia, the amplitudes of the a- and b-waves of the ERGs were evaluated. One day after the ischemia, apoptosis was determined by TUNEL staining, and at 7 days, the number of RGCs was counted in paraffin sections. Results: There was no significant difference in the ERG amplitudes between the two groups. However, there were fewer TUNEL-positive cells especially in the RGC layer in the nilvadipine group, and the number of RGCs was significantly greater in the nilvadipine-treated animals. Conclusion: These results indicate that nilvadipine has a neuroprotective effect for retinal ganglion cells against retinal ischemia.
Keywords: 489 neuroprotection • 448 ischemia • 390 drug toxicity/drug effects