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: We conclude that renal compensatory mechanisms are preserved during isoflurane - induced hypotension and that renal function and hemodynamics quickly return to normal when normotension is resumed .
### Output Text:
We conclude that renal compensatory mechanisms are preserved during <span class="chemical">isoflurane</span> - induced hypotension and that renal function and hemodynamics quickly return to normal when normotension is resumed . 