[The influence of angiotensin II receptor blockade on the expressions of Col I and TIMP-1 mRNA in cardiac fibroblast of adult rat].

To investigate the role of angiotensin II receptor type 2 (AT2) on collagen metabolism in cardiac fibroblast, and the difference between AT2 and angiotensin II receptors type 1 (AT1). Adult rat cardiac fibroblasts were isolated and cultured. The cells were divided into 4 groups: Angiotensin II (Ang II), Ang II + Losartan, Ang II + PD123319, Ang II + Losartan + PD123319. Semiquantitative reverse transcription PCR was used to determine the mRNA levels of collagen I (Col I ) and tissue inhibitor of metalloproteinase 1 (TIMP-1). Losartan-treatment making AT1 blockade decreased Col I mRNA to 71.8% in cardiac fibroblasts, AT2 blockade from PD123319-treatment decreased Col I mRNA to 81.5%, co-treatment of both AT1 and AT2 blockade decreased Col I mRNA to 50.9% ; the AT1 blockade with Losartan-treatment decreased TIMP-1 mRNA to 88.1% in cardiac fibroblasts, AT2 blockade by PD123319-treatment decreased TIMP-1 mRNA to 75.4%, Both AT1 and AT2 blockade by co-treatment decreased TIMP-1 mRNA to 44.1%. AT2 receptor is involved in collagen metabolism in cardiac fibroblast by regulating the levels of Col I and TIMP-1 mRNA.