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: VCM administration to control rats significantly increased renal malondialdehyde ( MDA ) and urinary N - acetyl - beta - d - glucosaminidase ( NAG , a marker of renal tubular injury ) excretion but decreased superoxide dismutase ( SOD ) and catalase ( CAT ) activities .
### Output Text:
<span class="chemical">VCM</span> administration to control rats significantly increased renal <span class="chemical">malondialdehyde</span> ( <span class="chemical">MDA</span> ) and urinary N - acetyl - beta - d - glucosaminidase ( NAG , a marker of renal tubular injury ) excretion but decreased <span class="chemical">superoxide</span> dismutase ( SOD ) and catalase ( CAT ) activities . 