This study aimed to investigate the underlying mechanism of Zhenwu Decoction in the treatment of heart failure by regulating electrical remodeling through the transient outward potassium current(I_(to))/voltage-gated potassium(Kv) channels. Five normal SD rats were intragastrically administered with Zhenwu Decoction granules to prepare drug-containing serum, and another seven normal SD rats received an equal amount of distilled water to prepare blank serum. H9c2 cardiomyocytes underwent conventional passage and were treated with angiotensin Ⅱ(AngⅡ) for 24 h. Subsequently, 2%, 4%, and 8% drug-containing serum, simvastatin(SIM), and BaCl_2 were used to interfere in H9c2 cardiomyocytes for 24 h. The cells were divided into a control group [N, 10% blank serum + 90% high-glucose DMEM(DMEM-H)], a model group(M, AngⅡ + 10% blank serum + 90% DMEM-H), a low-dose Zhenwu Decoction-containing serum group(Z1, AngⅡ + 2% drug-containing serum of Zhenwu Decoction + 8% blank serum + 90% DMEM-H), a medium-dose Zhenwu Decoction-containing serum group(Z2, AngⅡ + 4% drug-containing serum of Zhenwu Decoc-tion + 6% blank serum + 90% DMEM-H), a high-dose Zhenwu Decoction-containing serum group(Z3, AngⅡ + 8% drug-containing serum of Zhenwu Decoction + 2% blank serum + 90% DMEM-H), an inducer group(YD, AngⅡ + SIM + 10% blank serum + 90% DMEM-H), and an inhibitor group(YZ, AngⅡ + BaCl_2 + 10% blank serum + 90% DMEM-H). The content of ANP in cell extracts of each group was detected by ELISA. The relative mRNA expression levels of ANP, Kv1.4, Kv4.2, Kv4.3, DPP6, and KChIP2 were detected by real-time quantitative PCR. The protein expression of Kv1.4, Kv4.2, Kv4.3, DPP6, and KChIP2 was detected by Western blot. I_(to) was detected by the whole cell patch-clamp technique. The results showed that Zhenwu Decoction at low, medium, and high doses could effectively reduce the surface area of cardiomyocytes. Compared with the M group, the Z1, Z2, Z3, and YD groups showed decreased ANP content and mRNA level, increased protein and mRNA expression of Kv4.2, Kv4.3, DPP6, and KChIP2, and decreased protein and mRNA expression of Kv1.4, and the aforementioned changes were the most notable in the Z3 group. Compared with the N group, the Z1, Z2, and Z3 groups showed significantly increased peak current and current density of I_(to). The results indicate that Zhenwu Decoction can regulate myocardial remodeling and electrical remodeling by improving the expression trend of Kv1.4, Kv4.2, Kv4.3, KChIP2, and DPP6 proteins and inducing I_(to) to regulate Kv channels, which may be one of the mechanisms of Zhenwu Decoction in treating heart failure and related arrhythmias.
Rats ; Animals ; Myocytes, Cardiac ; Atrial Remodeling ; Rats, Sprague-Dawley ; Heart Failure/metabolism* ; RNA, Messenger/metabolism* ; Potassium

The cerebral ischemia-reperfusion model was established to investigate the anti-oxidation and anti-apoptosis mechanism of Xinshao formula on the cerebral ischemia reperfusion injury in rats. SD rats were randomly divided into five groups: sham operation group, model group, and low, middle and high-dose Xinshao formula groups (0.31, 0.62, 1.25 g·kg⁻¹). After administration with Xinshao formula for 7 days, the rats were used to establish the cerebral ischemia-reperfusion model. The neurological behavior was evaluated. TTC staining was implemented to determine the volume of cerebral infarction. The levels of ROS, SOD, GSH-PX, NO and iNOS in serum were examined, and the mRNA and protein levels of Bcl-2, Bax and caspase 3 in hippocampal CA1 were detected by qRT-PCR, immunohistochemical assay and Western blot. It is found that Xinshao formula could significantly reduce the symptoms of nervous function and the volume of cerebral infarction in MACO rats. Compared with model group, the rats in Xinshao formula group showed increases in the activities of SOD and GSH-PX (<0.01), and decreases in the activities of iNOS and the contents of NO, ROS and MDA (<0.01). In addition, Xinshao formula could down-regulate the mRNA and protein levels of Bax and caspase 3 (<0.01), and up-regulated those of Bcl-2 (<0.01) in MACO rats. In conclusion, Xinshao formula showed aprotective effect on cerebral ischemia reperfusion injuryin rats, which may be associated with the promotion of anti-oxidation and anti-apoptosis.