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: In control rats , intravenous bromocriptine ( 150 microg / kg ) induced significant hypotension and tachycardia .
### Output Text:
In control rats , intravenous <span class="chemical">bromocriptine</span> ( 150 microg / kg ) induced significant hypotension and tachycardia . 