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: DM rats with mild glycosuria ( similar in degree to that of the P treated animals ) were also studied .
### Output Text:
DM rats with mild glycosuria ( similar in degree to that of the <span class="chemical">P</span> treated animals ) were also studied . 