Effect of prenatal phenytoin administration on brain tryptophan metabolism of rat offspring during the preweaning period.

Abstract

Serum 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) concentrations in control rat offspring increased progressively during the preweaning period reaching adult values by day 21. It has been shown the prenatal phenytoin administration (100 mg kg-1 orally, days 7-19 of pregnancy) increased serum tryptophan and brain tryptophan, 5-HT and 5-HIAA of rat offspring at 3 days of age but not at 4, 15 or 21 days of age. The effect of prenatal phenytoin administration on the offspring at 3 days of age was not observed when these pups were cross-fostered to control mothers at 2 days of age suggesting that the alteration in rain tryptophan metabolism during the development of tryptaminergic neurons in rat offspring, as a result of prenatal phenytoin administration is mediated through changes in lactation or nursing ability of the mothers. It is important that such non-specific factors are controlled when studying the effect of prenatally administered drugs on neonatal brain transmitter concentrations.