Neuroprotective effects of lidocaine in a rat spinal cord neurodegenerative model induced by Kainic acid

SISTI MS; NISHIDA F; ZANUZZI CN; PORTIANSKY EL

Congreso; FALAN Congress. Federation of Latin American and Caribbean Neuroscience Societies; 2016

Lidocaine is commonly used for local anesthesia and pain relief. It is known that the drug has cell proliferative and neuroprotective effects when administered at certain concentrations. The goal of the present work was to determine whether intraparenchymal injection of lidocaine along with a kainic acid (KA), reduce or inhibit the excitotoxicity of the latter on neurons of the rat spinal cord. Male Sprague Dawley rats were injected either with KA 1mM (KA1), lidocaine 0.5% (L05), KA1 mM + lidocaine 0.5% (KA1-L05), or saline solution (sham) at the C5 cervical segment. Intact rats were used as an additional control group. Motor and sensitive abilities were evaluated at days 1, 2, 3, 7 and 14, post injection (pi). Animals of the KA1-L05 group performed motor and sensitive tests significantly better than KA-treated animals. Behavioural tests were even better than those of the controls, although differences were not significant. Rats were euthanized either at day 1, 2, 3, 7 or 14 pi. The spinal cord was then extracted, segmented and processed. Neuronal cell counting performed on the C5 segment of KA-L05 was also higher than that of the other groups although significance was just observed against KA1 animals in all tested points. Lidocaine showed an inhibitory effect of the KA excitotoxicity and an increase in neuronal counting when simultaneously administered with the drug, thus indicating that a promising neuroprotective/neuroproliferating effect must be accounting.