passages.id: split_5_test_1320_passage
passages.type: progene_text
passages.text: However , a supraphysiological concentration of 20 kDa GH ( 150 ng / ml ) resulted in a significantly lower ( P < 0.05 ) downregulation of GHR / GHBP gene transcription compared with the downregulation achieved by this concentration of 22 kDa GH .