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


METHODS
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).


RESULTS
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%.


CONCLUSIONS
AT2 receptor is involved in collagen metabolism in cardiac fibroblast by regulating the levels of Col I and TIMP-1 mRNA.
Jiang
Xiao-ying
XY
Department of Physiology and Pathophysiology, Medical College of Xi'an Jiaotong University, Xi'an 710061, China.
Gao
Guang-dao
GD
D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D019808:Losartan / Q000494:pharmacology*; D009206:Myocardium / Q000166:cytology; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*
D047228:Angiotensin II Type 1 Receptor Blockers; D024042:Collagen Type I; D007093:Imidazoles; D011725:Pyridines; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; C073402:PD 123319; D019808:Losartan