ORAL MATERNAL INOSITOL SUPPLEMENTATION DOES NOT INCREASE RAT CONCEPTUS INOSITOL LEVELS

Lithium (Li) is an effective drug for prophylaxis and treatment of maj or affective disorders. It is teratogenic both to animals and human be ings. Depletion of inositol is associated both with lithium side effec ts and teratogenesis. There is no direct evidence showing that in huma ns Li-teratogenesis is associated with the phosphoinositol (PI) cycle. It is conceivable that the teratogenic effect of Li in humans is also associated with inositol depletion and therefore is amenable to inosi tol supplementation. To test the hypothesis that oral inositol may cro ss the placental barrier and may be useful as a protective supplement to lithium therapy during pregnancy, we studied the effect of 2.5% ino sitol in drinking water on embryonic inositol levels in rats. There wa s no effect on fetal inositol concentration. However, weight of embryo s of mothers receiving inositol was significantly higher. These data d o not support the concept that inositol supplementation may be useful in preventing human Li-induced teratogenesis.