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 contrast to the systemic renin - angiotensin system , which is suppressed in response to HS in male DS , intrarenal angiotensinogen expression is increased , and intrarenal levels of ANG II are not suppressed .
### Output Text:
In contrast to the systemic renin - <span class="chemical">angiotensin</span> system , which is suppressed in response to HS in male DS , intrarenal angiotensinogen expression is increased , and intrarenal levels of ANG II are not suppressed . 