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These rats , however , showed a significant increase in the somatostatin receptor density and dissociation constant , which correlated with a significant increase in the protein levels of somatostatin receptors .
 Chemical: somatostatin; Chemical: somatostatin
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: somatostatin; Chemical: somatostatin