Improvement of retinal functions after ischemia with L-arginine and its derivatives.
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.
Liu
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SX
Institute of Ocular Pharmacology, Texas A&M University College of Medicine, College Station, USA.
Chiou
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GC
Varma
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RS
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology*; D003623:Dark Adaptation; D004596:Electroretinography; D005260:Female; D007511:Ischemia / Q000188:drug therapy* / Q000503:physiopathology; D051381:Rats; D015424:Reperfusion; D012160:Retina / Q000187:drug effects / Q000503:physiopathology*; D012161:Retinal Artery / Q000503:physiopathology*; D015356:Retinal Artery Occlusion / Q000188:drug therapy* / Q000503:physiopathology
D001120:Arginine