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: These data suggest that pilocarpine produced antiarrhythmic actions on arrhythmic rat and guinea pig models induced by aconitine or ouabain via stimulating the cardiac M ( 3 ) - mAChR .
### Output Text:
These data suggest that <span class="chemical">pilocarpine</span> produced antiarrhythmic actions on arrhythmic rat and guinea pig models induced by <span class="chemical">aconitine</span> or <span class="chemical">ouabain</span> via stimulating the cardiac M ( 3 ) - mAChR . 