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: ANP did not cause significant changes in MAP in both strains as compared to vehicle , but it abolished AVP - induced MAP increase in WKY and SHR .
### Output Text:
ANP did not cause significant changes in MAP in both strains as compared to vehicle , but it abolished <span class="chemical">AVP</span> - induced MAP increase in WKY and SHR . 