passages.id: split_5_test_1965_passage
passages.type: progene_text
passages.text: Here we examined the effect of overexpressing the human AT2R in cultured porcine cardiac fibroblasts ( pFib ) on proliferation , procollagen I mRNA expression , and - as putatively underlying signal-transduction pathways - on mitogen - activated protein kinase ERK1 / ERK2 and phosphotyrosine phosphatase activities .