23534
The genetic ablation of adenosine A2ARs prevented nicotine - induced upregulation of alpha 7 nAChRs , without affecting alpha 4 beta 2 * receptor upregulation .
 Chemical: adenosine; Chemical: nicotine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: adenosine; Chemical: nicotine