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: Furthermore , the bradycardia that accompanied the noradrenaline - induced pressor effect in SHR was similar with and without chronic prazosin treatment despite a 47 - 71 % reduction of the pressor effect in chronic alpha 1 - receptor blocked SHR . ( ABSTRACT TRUNCATED AT 400 WORDS )
### Output Text:
Furthermore , the bradycardia that accompanied the <span class="chemical">noradrenaline</span> - induced pressor effect in SHR was similar with and without chronic <span class="chemical">prazosin</span> treatment despite a 47 - 71 % reduction of the pressor effect in chronic alpha 1 - receptor blocked SHR . ( ABSTRACT TRUNCATED AT 400 WORDS ) 