EFFECTS ON NEWBORN RATS OF REPEATED CARBARYL ADMINISTRATION DURING GESTATION

Pregnant rats orally received 1 or 5 mg/kg of carbaryl from the 11th to the last day of gestation. The new-born were separated from their treated dams and killed the day they were born or 6 days afterwards. The acetylcholinesterase (AchE) activities of the tissues (blood, brain and liver) of the mother and of the new-born were compared with those of the control animals. No significant decrease in the enzyme activity was noted in the investigated tissues, an increase was even seen in the maternal blood and liver. After receiving 50 mg/kg of carbaryl from the 19th to the last day of gestation, the AchE activity is increased in the blood and reduced in the brain of both mothers and new-borns. The weight analysis of the dams and the new borns only shows a significant decrease at the dose of 50 mg/kg. The observed increase of the AchE activity could represent adaptation by the animal to exposure to low doses of carbaryl. © 1979.