Upregulation of brain somatostatin and neuropeptide Y following lidocaine-induced kindling in the rat

Male Sprague-Dawley rats received a daily injection of 60 mg/kg of lidocain e (> 30 days), Twenty percent of rats developed convulsions (kindled rats) and remaining rats did not show convulsions (non-kindled rats). The level o f immunoreactive somatostatin (IR-SRIF) in kindled rats was significantly i ncreased in amygdala than that in non-kindled rats and control rats, Immuno reactive neuropeptide Y (IR-NPY) contents in kindled rats were significantl y increased in amygdala, hippocampus, cortex and striatum compared to non-k indled and control rats. The expression of SRIF mRNA in kindled rats produc ed a significant increase in amygdala, while NPY mRNA in kindled rats showe d an elevated expression in both amygdala and hippocampus. These results co incide with the previous findings with the elevated expression of SRIF and NPY mRNA in electrically and pharmacologically kindled models, suggesting t he important role of these peptides in the kindling phenomenon. (C) 2000 El sevier Science B.V. All rights reserved.