ABSTRACT
OBJECTIVE: To observe the effect of combined intervention of electroacupuncture (EA) and astragaloside IV(ASIV) on cardiac hypertrophy and transforming growth factor β 1 (TGF-β 1)/Smad signaling in isoproterenol (ISO) induced cardiac hypertrophy rats, so as to investigate its underlying mechanisms in improving myocardial fibrosis. METHODS: A total of 50 SD rats were randomly divided into 5 groups: normal control, model (ISO), Propranolol (PRO)，ASIV and EA＋ASIV groups (n＝10 in each group). The myocardial fibrosis model was established by intraperitoneal injection (i.p.) of ISO (10 mg·kg－1·d－1), once daily for 30 days. Rats of the control group were given normal saline (i.p.), those of the PRO group given with PRO (40 mg·kg－1·d－1, gavage), and those of the ASIV and EA＋ASIV groups were treated by gavage of ASIV (40 mg·kg－1·d－1), once daily for 30 days. EA (20 Hz, 6 V) was applied to bilateral "Neiguan" (PC 6) for 10 min, once every day for 30 d. The heart mass index (HMI, whole heart weight/body weight) and left ventricular (LV) mass index (LVMI, weight of the LV/body weight) were calculated to assess the state of cardiac hypertrophy. The enzyme linked immunosorbent assay (ELISA) was used to determine the levels of procollagen I carboxy-terminal propeptide (PICP，a marker of extracellular matrix remodeling) and carboxyterminal telopeptide of type I collagen (ICTP, a metabolite of type I collagen) in serum, and Western blot was used to test protein contents of TGF- β 1, Smad 2 / 3, Smad 4, Smad 7 in the left ventricle tissue of the heart. RESULTS: After modeling, the HMI and LVMI, serum PICP and ICTP contents and the expression levels of myocardial TGF-β 1, Smad 2/3 and Smad 4 proteins were significantly increased in the model (ISO) group (P 0.05). CONCLUSIONS: EA stimulation of PC 6 combined with ASIV can relieve cardiac hypertrophy and myocardial fibrosis in rats, which may be associated with its effects in regulating myocardial TGF-β 1/Smad signaling pathway.