[Effects of repeated nicotine uptake on brain inositol levels]

In the acute experiments, 30 minutes after nicotine was intraperitoneally injected at the doses of 0.5, 1.0, 1.0, 2.0, 2.0 mg/kg with 5 min interval, the inositol levels were increased in rats cerebral cortex and hippocampus rather than striatum. While the inositol level was decreased in rat cerebral cortex 30 minutes after lithium chloride was given at the dose of 10 mmol/kg. In the chronic experiments, after nicotine at the doses of 2.0-5.0 mg/kg was subcutaneouly injected twice a day for 14 days the inositol level was increased in rat cerebral cortex. In other experiments, nicotine was orally given at the dosese of 2.69, 6.26, 11.53 mg/kg.d for 64 days, the inositol level of rat cerebral cortex was also increased. These indicated that the effects of nicotine on inositol level of rat brain are different from those of lithium chloride, the inositol level of rat cerebral cortex can be increased by repeated administration of nicotine.