Ontogenic changes of kynurenine aminotransferase I activity and its expression in the chicken retina.

Kynurenine aminotransferases are key enzymes for the synthesis of kynurenic acid (KYNA), an endogenous glutamate receptor antagonist. The study described here examined ontogenic changes of kynurenine aminotransferase I (KAT I) activity and its expression in the chicken retina. KAT I activity measured on embryonic day 16 (E16) was significantly higher than at all other stages (E12, P0 and P7).

Oral citicoline treatment improves visual pathway function in glaucoma.

Background: Increased latency and reduced amplitude of visual evoked potentials (VEP), frequently encountered in ocular hypertension or open-angle glaucoma, suggest slowed neural conduction in the visual pathways. An improvement in VEP latency and amplitude has been reported following repeated intramuscular injections of citicoline, a neuroprotective drug. Our aim was to find whether citicoline given orally would produce a similar effect.

Alterations of kynurenic acid content in the retina in response to retinal ganglion cell damage.

The present study is the first to examine the modulation of retinal kynurenic acid (KYNA) content in response to N-methyl-D-aspartate (NMDA)-induced cell death in adult rat retinal ganglion cells (RGC). Adult Brown Norway rats were intravitreally injected with NMDA or PBS. Surviving RGC were retrogradely labeled with fluorogold and counted in wholemounts of retinas 2, 7 and 14 days after injection.

Changes of kynurenic acid content in the rat and chicken retina during ontogeny.

Background: Kynurenic acid (KYNA) is the only known endogenous glutamate receptor antagonist and neuroprotectant. After showing the presence of KYNA and its synthesising enzymes in the adult rat retina, we examined developmental changes of KYNA content in both vascularised rat and avascular chicken retinas.

Methods: Retinas from Brown Norway rats and White Leghorn chickens at different developmental stages between the embryonic and the adult stages were used.

Citicoline treatment increases retinal dopamine content in rabbits.

Citicoline (exogenous cytidine-5'-diphosphocholine) was reported to enhance dopaminergic neurotransmission in the brain. A few clinical studies showed beneficial effects of this drug on the function of the visual pathway in patients with glaucoma or amblyopia. The present study was aimed at determining whether citicoline could influence retinal catecholamine levels in adult male Albino rabbits.

Pharmacodynamics of citicoline relevant to the treatment of glaucoma.

Citicoline (exogenous CDP-choline) is a nontoxic and well-tolerated drug used in pharmacotherapy of brain insufficiency and some other neurological disorders, such as stroke, brain trauma, and Parkinson's disease. A few reports indicate that citicoline treatment may also be beneficial in glaucoma. Currently glaucoma is considered a neurodegenerative disease in which retinal ganglion cells (RGC) slowly die, likely in the apoptotic mechanism.