Efeitos da ingestão do ácido 2,4-diclorofenoxiacético sobre neurônios mioentéricos do duodeno de ratos (Rattus norvegicus) / Ingestion effects of herbicid 2,4-dichlorophenoxyacetic acid on myenteric neurons of the duodenum of rats (Rattus norvegicus)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The 2,4 dichlorophenoxyacetic acid (2,4-D) it is a herbicid thoroughly used in the agriculture and it is poisonous for the human beings and other animals. It presents neurotoxicity but its action mechanism in the nervous system is not totally known. There are evidences that herbicid actuate on selective mode in serotoninergics and dopaminergics neurons, but there isn?t significant studies to prove its discuss action on the peripheric nervous system. Among the effects succeeding of the intoxication with 2,4-D are gastrointestinal manifestations. The present work had as objective verifies the effects of the administration for 15 days of 5 μg and 2,5 μg/Kg of body weight of 2,4-D diluted in water in the duodenum myenteric neurons of the rats. In order to do so, 15 rats (Rattus norvegicus) were divided into three groups (n = 12): controls (C); treatment with 2,5μg/Kg of 2,4-D (B); and treatment with 5μg/Kg of 2,4-D (A). 15 days later, the animals were anesthetized, killed without pain and your duodenums were removed. The myenteric neurons were stained employing the Giemsa and the NADH-diaforase methods by means of whole mounts preparations. These whole mounts preparations were analyzed in light microscope to count the neurons and through image analysis software to measured the cellular body profile (CBP) of these neurons. The quantitative analysis evidenced reduction in the number of duodenum neurons in animals which received 2,4-D, in both techniques (p<0,05). Predominated in three groups neurons with size between 101 and 300 μm2. Incidence of big neurons (between 301 e 600 μm2) was significantly higher (p<0,05) in the treated with 2,4-D. The results suggest that the 2,4-D affect the myenteric plexus, and its action is expressed by reduction in neurons number and increase in incidence of big neurons.

ASSUNTO(S)

herbicid 4-d nervous system plexo mioentérico 4-d herbicida 2 2 sistema nervoso myenteric plexus

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