7180
Systemic ghrelin administration followed by consumption of regular food induced an increase in dopamine levels via preferential activation of mu opioid receptors , whereas systemic ghrelin administration followed by consumption of palatable food suppressed the increase in dopamine levels via preferential activation of kappa opioid receptors .
 Chemical: dopamine; Chemical: dopamine
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: dopamine; Chemical: dopamine