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: The present study examines the effect of 6 - day epinephrine treatment ( 100 micrograms / kg per h , s . c . ) on stimulus - induced ( 1 Hz ) endogenous neurotransmitter overflow from the isolated perfused kidney of vehicle - and epinephrine - treated rats .
### Output Text:
The present study examines the effect of 6 - day <span class="chemical">epinephrine</span> treatment ( 100 micrograms / kg per h , s . c . ) on stimulus - induced ( 1 Hz ) endogenous neurotransmitter overflow from the isolated perfused kidney of vehicle - and <span class="chemical">epinephrine</span> - treated rats . 