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: However , epinephrine treatment resulted in the incorporation of epinephrine into renal catecholamine stores such that approximately 40 % of the catecholamine present was epinephrine while the norepinephrine content was reduced by a similar degree .
### Output Text:
However , <span class="chemical">epinephrine</span> treatment resulted in the incorporation of <span class="chemical">epinephrine</span> into renal <span class="chemical">catecholamine</span> stores such that approximately 40 % of the <span class="chemical">catecholamine</span> present was <span class="chemical">epinephrine</span> while the <span class="chemical">norepinephrine</span> content was reduced by a similar degree . 