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 data indicate that diazepam acts through the benzodiazepine - GABA - chloride channel macromolecular complex within the central nervous system to facilitate reflex bradycardia mediated through baroreceptor reflexes in response to an acute increase in arterial pressure .
### Output Text:
The data indicate that <span class="chemical">diazepam</span> acts through the <span class="chemical">benzodiazepine</span> - <span class="chemical">GABA</span> - <span class="chemical">chloride</span> channel macromolecular complex within the central nervous system to facilitate reflex bradycardia mediated through baroreceptor reflexes in response to an acute increase in arterial pressure . 