In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Moreover , systemic lipopolysaccharide pretreatment ( 1 mg / kg ) attenuated local methamphetamine infusion - produced dopamine and 3 , 4 - dihydroxyphenylacetic acid depletions in the striatum , indicating that the protective effect of lipopolysaccharide is less likely due to interrupted peripheral distribution or metabolism of methamphetamine .
### Output Text:
Moreover , systemic <span class="chemical">lipopolysaccharide</span> pretreatment ( 1 mg / kg ) attenuated local <span class="chemical">methamphetamine</span> infusion - produced <span class="chemical">dopamine</span> and <span class="chemical">3 , 4 - dihydroxyphenylacetic acid</span> depletions in the striatum , indicating that the protective effect of <span class="chemical">lipopolysaccharide</span> is less likely due to interrupted peripheral distribution or metabolism of <span class="chemical">methamphetamine</span> . 