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: LF lowered ( P < 0 . 01 ) and dose dependently prevented ( P < 0 . 001 ) Dex - induced hypertension .
### Output Text:
LF lowered ( P < 0 . 01 ) and dose dependently prevented ( P < 0 . 001 ) <span class="chemical">Dex</span> - induced hypertension . 