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: CCB was reduced in WKY and SHR after LV administration of AVP during SN - induced hypotension .
### Output Text:
CCB was reduced in WKY and SHR after LV administration of <span class="chemical">AVP</span> during <span class="chemical">SN</span> - induced hypotension . 