OBJECTIVESTo elucidate the possible involvement of monoamine neurotransmitters in the development of neurobehavioral damage produced by acrylonitrile in drinking water in male rat brains.

METHODSTotally 30 male SD rats were randomly divided into three groups, the control group (n = 10), low dosage group (n = 10), and high dosage group (n = 10), which were respectively administered 0 mg/L, 50 mg/L, 200 mg/L acrylonitrile (AN) in drinking water. The treatment was lasted for 12 weeks. Seven animals were randomly selected from each group for determination of monoamine neurotransmitters in striatum and cerebellum by high performance liquid chromatography with electrochemical detector and activities of monoamine oxidase in cortex.

RESULTSThe contents of dopamine in the striatum of low and high dosage groups were decreased to (2.2 +/- 0.7) and (3.2 +/- 2.0) microg/g wet tissue, respectively, and compared with that of control group (9.0 +/- 4.2) microg/g wet tissue, the differences were statistically significant. There were no statistical differences among the contents of dopamine in the cerebellum of all rats, and the levels of 3,4-dihydroxyphenylacetic acid (DOPAC), the major metabolite of dopamine in the cerebellum were (186 +/- 41), (245 +/- 90) and (115 +/- 65) ng/g wet tissue in the control, low and high dosage groups, respectively and in low-dosage group they were significantly higher than those in other groups. There was dosage-dependently decreasing of the contents of serotonin of striatum in the control (249 +/- 34) ng/g wet tissue, low dosage (155 +/- 95) ng/g wet tissue and high dosage groups (128 +/- 101) ng/g wet tissue.

CONCLUSIONThis study underlines the importance of alterations in the monoamine neurotransmitters system as a possible causative mechanism behind the behavioural and functional changes produced by acrylonitrile.