[Effect of metabolic changes in the liver on the cytotoxic activity of cyclophosphamide in the incisor of rats].

The incisor of the rat is a sensitive biological indicator which records nutritive and hormonal disorders as well as toxic influences. The present investigation was aimed to provide information whether or not the manifestation of cyclophosphamide-caused hypoplasias could be altered by an induction (phenobarbital) or inhibition (carbon tetrachloride) of the liver biotransformation capacity. Cyclophosphamide (15 or 30 mg/kg) was injected intraperitoneally. Pretreatment of the rat with phenobarbital produced an increase (35%) of the malformation, whereas carbon tetrachloride led to a dose dependent decrease (30 or 50%). Our investigations suggest that the cyclophosphamide induced defect of the incisor is due to an alteration of the metabolic liver function.