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: In contrast , the protein abundances of Na ( + ) / H ( + ) exchanger type 3 ( NHE3 ) , Na ( + ) - K ( + ) - 2Cl ( - ) cotransporter ( BSC - 1 ) , and thiazide - sensitive Na ( + ) - Cl ( - ) cotransporter ( TSC ) were decreased .
### Output Text:
In contrast , the protein abundances of <span class="chemical">Na</span> ( + ) / <span class="chemical">H</span> ( + ) exchanger type 3 ( NHE3 ) , <span class="chemical">Na</span> ( + ) - <span class="chemical">K</span> ( + ) - <span class="chemical">2Cl</span> ( - ) cotransporter ( BSC - 1 ) , and <span class="chemical">thiazide</span> - sensitive <span class="chemical">Na</span> ( + ) - <span class="chemical">Cl</span> ( - ) cotransporter ( TSC ) were decreased . 