3450
This study aims to demonstrate that microcystin - LR ( MC - LR ) has toxic effects on the reproductive system of male Rana nigromaculata in vitro .
 Chemical: microcystin - LR; Chemical: MC - LR
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: microcystin - LR; Chemical: MC - LR