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: Stimulus - induced fractional overflow of neurotransmitter from the epinephrine - treated kidneys was approximately twice normal and consisted of both norepinephrine and epinephrine in proportions similar to those found in the kidney .
### Output Text:
Stimulus - induced fractional overflow of neurotransmitter from the <span class="chemical">epinephrine</span> - treated kidneys was approximately twice normal and consisted of both <span class="chemical">norepinephrine</span> and <span class="chemical">epinephrine</span> in proportions similar to those found in the kidney . 