EFFECTS OF 2,4-DICHLOROPHENOXYACETIC ACID ON CENTRAL-NERVOUS-SYSTEM OF DEVELOPMENTAL RATS - ASSOCIATED CHANGES IN GANGLIOSIDE PATTERN

Neonate rats were treated with 2,4-dichlorophenoxyacetic acid (2,4-D) from the 7th or 12th until the 17th or 25th postnatal day. Two drug do sages were used: 70 and 100 mg/kg body weight of 2,4-D. At the 17th da y of age, no changes were observed in body weight, protein and DNA con tent. However, 25-day-old treated pups showed diminutions in body and brain weight, protein and DNA levels, depending on doses and period of treatment. With respect to ganglioside levels, few changes were obser ved in treated animals until the 17th day of age. However, at the 25th day, with higher dose and longer treatment a diminution in all parame ters analyzed was observed. These results suggest a delay in CNS devel opment when pups were exposed to a very severe chemical injury with 2, 4-D. On the other hand, when the chemical injury was not too severe, t he brain would be capable to trigger biochemical mechanisms producing a plasticity response which is expressed as changes in ganglioside con tent and composition. (C) 1997 Elsevier Science B.V.