[Angiotensin II regulates the expression of collagens in rat heart].
OBJECTIVE
To testify the effect of angiotensin (Agn) II on the regulation and expression of collagen I, III genes in rat heart as well as the influence of DMP811 (a novel nonpeptide selective angiotension type 1 antagonist) on the effect of Ang II.


METHODS
Six-week-old male SD rats with osmotic minipump subcutaneously containing either Ang II or saline were used. (1) Saline-infused(control) group (n = 6), (2) Ang II-infused group (n = 6). (3) Ang II-infused and DMP811-treated (3 mg.kg-1.d-1, by gavage) group (n = 6). Ang II (200 ng.kg-1.min-1) or saline was continuously infused for 1 week. After extraction of cardiac total RNA, the levels of collagen I, III mRNA and proteins were measured with RT-PCR and Sirius red staining respectively.


RESULTS
Cardiac weight, cardiac weight/body weight radio, the mRNA levels of collagen I, III were increased by (4.7 +/- 0.4)%, (4.9 +/- 0.9)%, (22.0 +/- 4.7)% and (20.6 +/- 4.9)% respectively, in group 2 compared with those in group 1. The analysis of collagen on Sirius red-stained sections showed that Ang II increased the deposits of both collagen I and III. The above changes caused by Ang II could be inhibited fully by DMP811.


CONCLUSIONS
Ang II up-regulated the expressions of collagen I, III via angiotension type 1 receptor.
Cui
Z
Z
Biochemistry Division, Fu Wai Hospital, CAMS and PUMC, Beijing 100037.
Chen
X
X
Chen
L
L
Wang
M
M
Liu
L
L
D000804:Angiotensin II / Q000494:pharmacology*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D024042:Collagen Type I / Q000096:biosynthesis* / Q000235:genetics; D024061:Collagen Type III / Q000096:biosynthesis* / Q000235:genetics; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013777:Tetrazoles / Q000494:pharmacology; D020257:Ventricular Remodeling
D057911:Angiotensin Receptor Antagonists; D024042:Collagen Type I; D024061:Collagen Type III; D007093:Imidazoles; D012333:RNA, Messenger; D013777:Tetrazoles; D000804:Angiotensin II; C085640:DMP 811