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: OBJECTIVE : The aim of this study was to investigate whether fluoxetine given to castrated and noncastrated rats caused hyperprolactinemia and its effects with respect to adenomyosis .
### Output Text:
OBJECTIVE : The aim of this study was to investigate whether <span class="chemical">fluoxetine</span> given to castrated and noncastrated rats caused hyperprolactinemia and its effects with respect to adenomyosis . 