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: Plasma aldosterone levels increased in nephrotic mice of both genotypes and was followed by increased SGK1 protein expression in sgk1 ( + / + ) mice .
### Output Text:
Plasma <span class="chemical">aldosterone</span> levels increased in nephrotic mice of both genotypes and was followed by increased SGK1 protein expression in sgk1 ( + / + ) mice . 