Activities of glucose-metabolizing enzymes in experimental neurotoxic models with lipoate as an alleviator

Acrylamide (35 mg kg(-1) body wt, i.p.) and mercuric chloride (1 mg kg(-1)body wt, i.m.) were administered as specific and non-specific toxins, respectively, to induce neurotoxicity in rats for a period of 10 days. Two different concentrations (35 and 70 mg kg(-1) body wt, i.p.) of lipoic acid were given as prophylactic therapy to mitigate the toxic neuropathies. Homogenates of cerebrum, cerebellum and sciatic nerves were used for the determination of the activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), neuron-specific enolase (NSE), hexokinase, phosphoglucoisomerase, aldolase and glucose-6-phosphatase. Inhibition of the activities of these glucose-metabolizing enzymes by the neurotoxins emphasizes the reduction in glucose utilization by the neural tissues to impart its normal function. The degree of inhibition of the enzymes varies with both of the toxins. Acrylamide seems to be a specific inhibitor of GAPDH and NSE, whereas the inhibition caused by HgCl(2) on the enzymes was more general. Enhanced activities of the enzymes indicate increased glucose utility on lipoate administration. This result may be due to the detoxifying potency and possibly due to the cofactor vitality of lipoate.