[Effects of pyrethroids on dopamine and its metabolites in nigrostriatum of male rats].
OBJECTIVE
To investigate the effects of pyrethroids on nigrostriatal dopaminergic pathways in male rats and its mechanism.


METHODS
Different doses of permethrin (PM, 200, 400 mg/kg) and deltamethrin (DM, 6.25, 12.50 mg/kg) in corn oil were administered to rats by gavage once daily for ten days, then the contents of dopamine (DA) and its metabolites, 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the substantial nigra and striatum were analyzed by HPLC-fluorescence detection.


RESULTS
The contents of DA in striatum in four administered groups were decreased to a certain extent. DA in 6.25 mg/kg DM group [(6.14 +/- 0.57) microg/g wet weight] was lower than that in control group [(9.46 +/- 1.95) microg/g wet weight], P < 0.05. The turnover rate of DA in 200, 400 mg/kg PM and 6.25, 12.5 mg/kg DM groups increased by 133.33%, 166.67%, 166.67%, 266.67% respectively (P < 0.05 or P < 0.01), however there was no significant difference in DA and DOPAC in substantial nigra between control and administered groups.


CONCLUSIONS
DM may inhibit tyrosine hydroxylase and decrease the level of DA in striatum, and both pyrethroid pesticides may increase the metabolism of dopamine in striatum.
Liu
Gong-ping
GP
Department of Toxicology, Tongji Medical College of Huazhong Science and Technology University, Wuhan 430030, China.
Shi
Nian
N
Liang
Jun-hua
JH
Chen
Liang
L
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D006719:Homovanillic Acid / Q000378:metabolism; D007306:Insecticides / Q000494:pharmacology*; D008297:Male; D009570:Nitriles / Q000494:pharmacology*; D026023:Permethrin / Q000494:pharmacology*; D011722:Pyrethrins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism*
D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; D015102:3,4-Dihydroxyphenylacetic Acid; C017180:decamethrin; D026023:Permethrin; D004298:Dopamine; D006719:Homovanillic Acid