Purpose
To investigate whether NS-7, 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride, a novel Na+/Ca2+ channel blocker, can protect the rat retina subjected to ischemia–reperfusion insult.
Methods
To evaluate the protective effect of NS-7 against retinal damage, the drug was administered before and after ischemia–reperfusion. Damage to the retina was assessed by measuring the thickness of the inner plexiform layer (IPL) and the outer nuclear layer (ONL) of each eye. In a subsequent experiment, electroretinographic (ERG) evaluation was also used.
Results
In histopathologic evaluation, ischemia–reperfusion injury caused a significant reduction of IPL thickness (measured as the IPL/ONL ratio). In the NS-7-treated group, retinal damage was partially prevented by a concentration of 0.25 mg/kg per day. In the ERG evaluation, ischemia–reperfusion injury caused a reduction of A- and B-wave amplitudes. NS-7 treatment significantly prevented the reduction of the B wave at a concentration of 0.1 or 0.3 mg/kg, while the reduction of the A wave was not significantly affected.
Conclusions
NS-7 has neuroprotective effects against retinal damage resulting from subjection to ischemia. In addition, NS-7 can be used as an agent for treating acute ischemic retinopathy, including diseases associated with very high intraocular pressure, such as acute angle-closure glaucoma. Jpn J Ophthalmol 2005;49:371–376 © Japanese Ophthalmological Society 2005