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: The rapid reversion after insulin treatment excludes the possibility that streptozotocin in itself causes the ISO resistance and points towards a direct insulin effect on myocardial catecholamine sensitivity in diabetic rats .
### Output Text:
The rapid reversion after insulin treatment excludes the possibility that <span class="chemical">streptozotocin</span> in itself causes the <span class="chemical">ISO</span> resistance and points towards a direct insulin effect on myocardial <span class="chemical">catecholamine</span> sensitivity in diabetic rats . 