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: Testosterone replacement in castrated DS rats increased BP , renal injury , and upregulation of renal angiotensinogen associated with HS diet .
### Output Text:
<span class="chemical">Testosterone</span> replacement in castrated DS rats increased BP , renal injury , and upregulation of renal angiotensinogen associated with HS diet . 