4901
The double - staining immunohistochemical evidence showed that OX1R immunoreactive ( OX1R - IR ) cells and neuronal nitric oxide synthase ( nNOS ) or inducible nitric oxide synthase ( iNOS ) immunoreactive ( IR ) cells were co - localizated in the RVLM .
 Chemical: nitric oxide; Chemical: nitric oxide
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: nitric oxide; Chemical: nitric oxide