Critical evaluation of the effects of chronic ocular treatment with the dipeptide N-acetyl-aspartyl-glutamic acid (Mg-NAAGA). Serological, histological and ultrastructural observations

Ocular and systemic subacute Mg-Naaga tolerability was evaluated in beagle dogs, treated at the same time by intraconjunctival application (0.05 ml q.i.d. of a 6% collyrium preparation), and by oral route (150-300 or 600 mg/kg/die of the pure substance in a single dose). Before the beginning of the treatment and every 30 days thereafter blood samples were drawn in order to perform routine laboratory analyses. At the end of the study 4 animals per group were sacrificed both eyes with optic nerves and principal splanchnic organs removed, and then examined by light and electron microscopy. Hematochemical and histological investigations clearly demonstrated the absolute absence of toxicity of the drug. The ultrastructural investigation confirmed the lack of toxicity, and demonstrated the activation of tissutal clearance mechanisms elicited by the drug at ocular level.