passages.id: split_1_test_1718_passage
passages.type: progene_text
passages.text: In order to obtain such a specific inhibitor , a variety of antisense oligonucleotides ( ASO ) against rat P2X3 was tested , and dose - dependent , sequence - specific downregulation of the rat P2X3 receptor ( expressed in a Chinese hamster ovary cell line [ CHO - K1 ] ) on the mRNA , protein , and functional levels was observed .