Neuroprotective effect of citicoline on retinal cell damage induced by kainic acid in rats.
OBJECTIVE
To examine whether citicoline has a neuroprotective effect on kainic acid (KA)-induced retinal damage.


METHODS
KA (6 nmol) was injected into the vitreous of rat eyes. Citicoline (500mg/kg, i.p.) was administered to the rats once before and twice a day after KA-injection for 3- and 7-day intervals. The neuroprotective effects of citicoline were estimated by measuring the thickness of the various retinal layers using hematoxylin-eosin (H&E) staining. In addition, immunohistochemistry was conducted to elucidate the expression of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS).


RESULTS
Morphometric analysis of retinal damage in KA-injected eyes showed significant cell loss in the inner nuclear layer (INL) and inner plexiform layer (IPL) of the retinas at 3 and 7 days after KA injection, but not in the outer nuclear layer (ONL). At 3 days after citicoline treatment, no significant changes were detected in the retinal thickness and immunoreactivities of eNOS and nNOS. The immunoreactivities of eNOS and nNOS increased in the retina at 7 days after the KA injection. However, prolonged treatment for 7 days significantly attenuated the immunoreactivities and the reduction of thickness.


CONCLUSIONS
The results indicate that citicoline has a neuroprotective effect on KA-induced neurotoxicity in the retina.
Han
Yong Seop
YS
Department of Ophthalmology, College of Medicine, Gyeongsang National University, Jinju, Korea.
Chung
In Young
IY
Park
Jong Moon
JM
Yu
Ji Myeong
JM
D000818:Animals; D003566:Cytidine Diphosphate Choline / Q000494:pharmacology*; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009498:Neurotoxins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000187:drug effects* / Q000473:pathology*
D018696:Neuroprotective Agents; D009498:Neurotoxins; D003566:Cytidine Diphosphate Choline; D007608:Kainic Acid