Chronic dietary lithium induces increased levels of myo-inositol-1-phosphatase activity in rat cerebral cortex homogenates

The monovalent lithium ion inhibits the enzyme myo-inositol-1-phosphatase at concentrations comparable to those which are useful in the treatment of manic depressive illness. However, dialyzed cortical homogenates from rats which have been fed diets containing lithium carbonate demonstrate increased myo-inositol-1-phosphate phosphatase activity. Over a 4-week period, there is an approximate doubling of the lithium-sensitive myo-inositol-1-phosphatase activity in the homogenate.