The expression of transforming growth factor-β1 in myocardial tissue and concentration of serum B-type natriuretic peptide in myocardial remodeling of Sprague-Dawley rats treated with carvedilol

R. Yi, G. Xiangyu, S. Min

Department of Pediatrics, The Affiliated Xuzhou Hospital of Medical College of Southeast University, Xuzhou, China. g.xy@163.com

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• Pharmacology

OBJECTIVE: The objective of this study was to observe the expression of transforming growth factor-β1 (TGF-β1) in myocardial tissue and the concentration of serum B-type natriuretic peptide (BNP) in myocardial remodeling of Sprague-Dawley rats induced by isoproterenol (ISO) and the effects of carvedilol intervention.

MATERIALS AND METHODS: Thirty rats were divided randomly into three groups: (1) Control group: rats were injected with 5 mL/(kg·d) of saline for 10 days, followed by 10 mL/(kg·d) of saline by gavage for 4 weeks. (2) Model group: rats were injected with 5 mg/(kg·d) ISO for 10 days, followed by 10 mL/(kg·d) of saline by gavage for 4 weeks. (3) Treatment group: rats were injected with 5 mg/(kg·d) ISO for 10 days, followed by 10 mg/(kg·d) carvedilol by gavage for 4 weeks. Following treatments, the Cardiac Weight Index (CWI) was measured. The pathological changes to myocardial tissue were observed by HE staining and Masson’s trichrome staining. The mRNA expression of TGF-β1 was determined by RT-PCR. The protein expression of TGF-β1 was detected by immunohistochemistry and Western blot. The concentration of serum BNP was measured by ELISA.

RESULTS: According to our results, no significant pathological changes were observed in myocardial tissue of the control group. The denaturation, hypertrophy, edema and necrosis of myocardial cells as well as increased collagen fibers in myocardial tissue of the model group, were more pronounced compared to the treatment group. The CWI, level of TGF-β1 in myocardial tissue, and the concentration of serum BNP of the model group, were significantly higher than that of the treatment group, and those of the treatment group were significantly higher than in the control group. There were significant differences among the three groups. There were also significant differences between any two groups.

CONCLUSIONS: The expression of TGF-β1 in myocardial tissue was upregulated and the concentration of serum BNP was increased in myocardial remodeling of SD rats induced by ISO. Carvedilol intervention can downregulate the expression of TGF-β1 and decrease the concentration of BNP, inhibiting myocardial remodeling, and improve cardiac function.

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