Nonspecific Esterases in the Brain and Amniotic Fluid of Rat Fetuses Following Maternal Exposure to Cyclophosphamide

Abstract

Preliminary data are presented on the activity of nonspecific esterases in brain and amniotic fluid of normal and exencephalic fetus of Wistar rats treated with single injection of 20 mg/kg cyclophosphamide on day 13 of gestation. In the experimental animal, a reduction in total esterase activity is observed in the brain (74% of control), while activity in the amniotic fluid shows a 40% increase. Eserine treatment indicates that the low esterase activity in the brain is due to a lack of cholinesterases. Inhibition studies with diisopropylfluorophosphate (DFP) points to the presence of a high proportion of organophosphate‐resistant esterases in the amniotic fluid of both control and experimental animals. Isoelectric focussing on thin layer polyacrylamide gel shows deletion of the fastest migrating cathodal isozyme in the experimental samples of the brain and amniotic fluid in 50% of cases. The significant increase of enzyme activity in the amniotic fluid clearly underlines the future scope for employing nonspecific esterase level as an additional parameter in the prenatal diagnosis of central nervous malformations.