Wernicke's encephalopathy is a neuropsychiatric disorder resulting from thiamine deficiency (TD) and is characterized by neuronal loss, astrocytic proliferation and microglial activation. Cyclooxygenases (COX) are enzymes which catalyze the first step in the synthesis of prostanoids. COX-1 is expressed constitutively and COX-2 is the inducible isoform. Groups of TD rats and pair-fed controls were killed at presymptomatic and symptomatic stages of encephalopathy. Cresyl violet and NeuN staining showed decreased numbers of neuronal cells in vulnerable regions (medial thalamus and inferior colliculus) but not in a spared region (frontal cortex). Numbers of GFAP-positive and OX-42-positive cells were increased at symptomatic stage of encephalopathy. Expression of COX-2 mRNA and neuronal COX-2 immunoreactivity were selectively increased in vulnerable regions of TD rats at symptomatic stages of encephalopathy. Nimesulide, a highly selective COX-2 inhibitor, lowered PGE2 levels and precipitated the progression of encephalopathy suggesting that COX-2 in this model is conferring neuroprotection.

No description available.