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: Tail blood pressure , urinary NOx excretion , plasma malondialdehyde ( MDA ) , and endothelial and inducible NOS ( eNOS and iNOS ) isotypes in the aorta and kidney were measured .
### Output Text:
Tail blood pressure , urinary NOx excretion , plasma <span class="chemical">malondialdehyde</span> ( <span class="chemical">MDA</span> ) , and endothelial and inducible NOS ( eNOS and iNOS ) isotypes in the aorta and kidney were measured . 