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: Exercise - induced myocardial ischemia was marked predominantly by increased heart rate and rate - pressure product with a minor contribution of end - diastolic volume , while epinephrine - induced ischemia was characterized by a marked increase in contractility and a less pronounced increase in heart rate and rate - pressure product .
### Output Text:
Exercise - induced myocardial ischemia was marked predominantly by increased heart rate and rate - pressure product with a minor contribution of end - diastolic volume , while <span class="chemical">epinephrine</span> - induced ischemia was characterized by a marked increase in contractility and a less pronounced increase in heart rate and rate - pressure product . 