ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of deltamethrin on tyrosine hydroxylase in nigrostriatum of male rats.</p><p><b>METHODS</b>Sprague-Dawley rats were daily treated with deltamethrin at 6.25 or 12.5 mg/kg body weight by gavage for 10 days. Then HPLC-fluorescence detection was used to analyze the contents of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homoranillic acid (HVA) in substantial nigra and striatum. The activities of tyrosine hydroxylase (TH) were also detected by HPLC-fluorescence detection. TH mRNA or TH protein levels were measured by RT-PCR and immunohistochemistry method.</p><p><b>RESULTS</b>The content of DA in striatum was significantly decreased by the treatments, suggesting an inhibition of DA synthesis by deltamethrin. The contents of DA metabolites DOPAC and HVA increased, indicating increased dopamine turnover. Furthermore, deltamethrin significantly decreased the activity, as well as the mRNA and protein levels of TH.</p><p><b>CONCLUSIONS</b>These findings reveal a novel aspect of deltamethrin neurotoxicity and suggest tyrosine hydroxylase as a molecular target of deltamethin on dopamine metabolism in the nigrostriatal pathway.</p>
Subject(s)
Animals , Male , Rats , 3,4-Dihydroxyphenylacetic Acid , Metabolism , Corpus Striatum , Metabolism , Dopamine , Metabolism , Gene Expression Regulation, Enzymologic , Hominidae , Insecticides , Toxicity , Levodopa , Metabolism , Nitriles , Toxicity , Pyrethrins , Toxicity , RNA, Messenger , Metabolism , Rats, Sprague-Dawley , Substantia Nigra , Metabolism , Tyrosine 3-Monooxygenase , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of pyrethroids on nigrostriatal dopaminergic pathways in male rats and its mechanism.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>
Subject(s)
Animals , Male , Rats , 3,4-Dihydroxyphenylacetic Acid , Metabolism , Chromatography, High Pressure Liquid , Corpus Striatum , Metabolism , Dopamine , Metabolism , Homovanillic Acid , Metabolism , Insecticides , Pharmacology , Nitriles , Pharmacology , Permethrin , Pharmacology , Pyrethrins , Pharmacology , Rats, Sprague-Dawley , Substantia Nigra , MetabolismABSTRACT
Based on avian leukosis virus ( ALV) p19 gene terminal nucleotide sequence, a 82 bp double-stranded DNA fragment was chemically synthesized and cloned into the expression vector pGEMEX-1. The sequencing result indicated th at the cloned fragment was a correct version of the one designed both in nucleot ide sequence and in its open reading frame. The recombinant was used to transfor m E.coli BL21 (DE3). The cloned fragment was expressed as a fused protein wi th T7 gene 10 leader peptide and was shown to be 34 kD in size on SDS-PAGE gel when induced with 1 mmol/L IPTG. The expression product was able to bind immunol ogically to rabbit anti-ALV serum in Western-blot assay and is being tested to differentiate exogenous from endogenous ALV.