3190
Metformin directly inhibits ghrelin secretion through AMP - activated protein kinase in rat primary gastric cells .
 Chemical: Metformin; Chemical: AMP
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: Metformin; Chemical: AMP