Retinal ischemia was created by occlusion of rat central retinal artery for 30 minutes. The loss of
retinal function was indicated by the loss of b-wave of electroretinogram. The recovery of
retinal function after reperfusion of central retinal artery was observed with the gradual recovery of b-wave amplitude to approximately 20% of original b-wave amplitude. When
L-arginine (RVC-579) was administered at the time of retina
ischemia, the b-wave amplitudes recovered up to 64% of original height and were significantly higher than corresponding controls at 120, 180, and 240 min after
ischemia. When the derivative of
L-arginine, N alpha-
benzoyl-L-arginine ethyl ester (RVC-578), was administered, the b-wave recovery was significantly higher than corresponding controls at 90, 120, 180, and 240 min after
ischemia; the recovery reached 51% of the original b-wave value. These results indicate that the
L-arginine and its lipophilic derivatives could be used for the treatment of ischemic retinopathy. Since
L-arginine is a natural
amino acid, it is not expected to produce major side effects, if any, and could pave the way for the development of a safer
drug to be used in the clinics. Compounds which increase the formation of NO in vivo, dilate blood vessels. Both
L-arginine and RVC-578 can be placed in this category. They may improve effects of
retinal ischemia by increasing NO production.