Effects of rhBNP on myocardial fibrosis after myocardial infarction in rats.
OBJECTIVE
We aimed to observe the effects and mechanism of rhBNP treatment on myocardial fibrosis (MF) after myocardial infarction (MI).


METHODS
SPF rats were separated into 3 groups: normal, MI (ligation of left coronary artery), and MI + rhBNP (recombinant human brain natriuretic peptide). Rats in MI + rhBNP group were given 30 μg/kg for 2 days before modeling and for 4 weeks after modeling. mRNA levels and the expression levels of TGF-β1 (transforming growth factor) and CTGF (connective tissue growth factor) in 3 groups were analyzed using the RT-qPCR and western blotting analysis, respectively. Furthermore, myocardial volume fraction (CVF) was analyzed using the Sirius Red F3B (SR) while the percentage of type I and III collagen in 3 groups were analyzed using the immunohistochemical staining.


RESULTS
Compared with the normal group, the levels of TGF-β1, CTGF, CVF, type I and III collagen were higher in MI group. However, mRNA levels of TGF-β1 and CTGF were significantly decreased in MI + rhBNP compared to MI groups. Expression of TGF-β1 was lower while that of CTGF was higher in MI + rhBNP group than that in MI group. Besides, CVF, and type I and III collagen were lower in MI + rhBNP group compared with MI group.


CONCLUSIONS
rhBNP could significantly decrease the TGF-β1 and CTGF levels in post-MI so as to inhibit the type I and III collagen deposition in MF of post-MI. rhBNP will be benefit for the improvement of MF.
Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University Harbin 150001, China.
Zhendong
Z
Su
Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University Harbin 150001, China.
Guoqian
G
Wei
Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University Harbin 150001, China.
Li
L
Wei
Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University Harbin 150001, China.
Junyan
J
Liu
Department of Cardiology, The Fourth Affiliated Hospital of Harbin Medical University Harbin 150001, China.
Xueqi
X
Li
D000818:Animals; D015153:Blotting, Western; D003094:Collagen / Q000096:biosynthesis / Q000187:drug effects; D004195:Disease Models, Animal; D005355:Fibrosis / Q000473:pathology; D006321:Heart / Q000187:drug effects*; D007150:Immunohistochemistry; D009203:Myocardial Infarction / Q000473:pathology*; D009206:Myocardium / Q000473:pathology*; D020097:Natriuretic Peptide, Brain / Q000494:pharmacology*; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D011994:Recombinant Proteins; D020097:Natriuretic Peptide, Brain; D003094:Collagen
Recombinant human brain natriuretic peptide (rhBNP); TGF-β1; connective tissue growth factor (CTGF); myocardial fibrosis; myocardial infarction