1520
Male Sprague - Dawley rats fitted with a chronic jugular venous catheter were exposed to either an emotional stressor ( elevated platform - exposure ) or immune challenge ( systemic interleukin - 1 beta administration ) .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None