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: We report that prenatally protein deprived ( PD ) female rats showed an increased stereotypic response to apomorphine and an increased locomotor response to amphetamine in adulthood .
### Output Text:
We report that prenatally protein deprived ( PD ) female rats showed an increased stereotypic response to <span class="chemical">apomorphine</span> and an increased locomotor response to <span class="chemical">amphetamine</span> in adulthood . 