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: Intravenous infusion of the ganglionic blocker hexamethonium resulted in a rapid decline in MAP that eliminated the dietary sodium chloride - induced increase in MAP in both groups .
### Output Text:
Intravenous infusion of the ganglionic blocker <span class="chemical">hexamethonium</span> resulted in a rapid decline in MAP that eliminated the <span class="chemical">dietary sodium chloride</span> - induced increase in MAP in both groups . 