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: Compared to wild - type mice , treatment of PPARalpha - / - mice with amiodarone resulted in an increased rate and extent of total body weight loss .
### Output Text:
Compared to wild - type mice , treatment of PPARalpha - / - mice with <span class="chemical">amiodarone</span> resulted in an increased rate and extent of total body weight loss . 