Effect of ouabain on intracellular Ca(2+) concentration in rat vascular smooth muscle cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of ouabain on intracellular Ca(2+) concentration ([Ca(2+)]i) in thoracic aorta vascular smooth muscle cells (VSMCs) in vitro.</p><p><b>METHODS</b>Primary SD rat thoracic aorta VSMCs were cultured by tissue adherent method and identified by immunochemistry. The binding ability between ouabain and VSMCs was detected by autoradiography, and fluo 3-AM (a Ca(2+) fluorescent probe) was employed to investigate whether ouabain affected VSMCs within a short period of time. The effect of a truncated fragment of the sodium pump α2 subunit was assayed in antagonizing the effect of ouabain on [Ca(2+)]i in the VSMCs.</p><p><b>RESULTS</b>Within the concentration range of 0.1-100 nmol/L, ouabain was found to dose-dependently bind to the VSMCs. Different concentrations of ouabain (0-3200 nmol/L) caused a transient, dose-dependent increase in [Ca(2+)]i in the VSMCs, which was antagonized by the application of the truncated fragment of sodium pump α2 subunit.</p><p><b>CONCLUSIONS</b>Elevations in [Ca(2+)]i in the VSMCs can be the cytological basis of high ouabain-induced hypertension. The truncated fragment of the sodium pump α2 subunit can antagonize ouabain-induced increase of [Ca(2+)]i in the VSMCs, which provides a clue for understanding the pathogenesis of and devising a therapeutic strategy for high ouabain-induced hypertension.</p>

Preparation and characterization of polyclonal antibodies against rat sodium pump alpha 2 subunit M1-M2 extra membrane fragment / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare polyclonal antibodies against sodium pump alpha 2 subunit M1-M2 extramembrane fragment (NKAα2 EM1) for studying the pathogenesis of hypertension.</p><p><b>METHODS</b>According to the GenBank data, the amino acid sequence of NKAα2 EM1 was obtained and the target peptide (LAAMEDEPSNDN) was synthesized using a peptide synthesizer with Fmoc method and purified with high-performance liquid chromatography. The synthesized peptide was then coupled to KLH for immunizing New Zealand white rabbits for 4 times to obtain the antiserum. The IgG antibodies against the synthetic peptide, after affinity purification with Protein A, were used for detecting NKAα2 EM1 expression in rat aortic vascular smooth muscle cells by enzyme-linked immunosorbent assay and immunocytochemistry (ICC).</p><p><b>RESULTS</b>The synthesized peptide fragment , which consisted of 13 amino acid residues including one derivatized cysteine residue in the N-terminal (LAAMEDEPSNDN-C), had a theoretical relative molecular mass of 1408.48 D with a measured relative molecular mass of 1407.90 D and a purity exceeding 85.5%. The titer of the antiserum was more than 1:512 000, and the purified IgG antibody concentration was 0.965 mg/ml after purification with Protein A. At a 1:1000 dilution (final concentration of 1 µg/ml), the titer of the purified IgG antibody was more than 1:256 000. The purified IgG antibody could be used at 1:100 to 1:200 dilutions for for immunocytological examination of formalin-fixed cells.</p><p><b>CONCLUSION</b>The anti-NKAα2 EM1 polyclonal antibodies obtained can be used in ELISA and immunocytochemistry for detecting the sodium pump alpha 2 subunit in formalin-fixed tissue or cells to facilitate investigation of the relationship between sodium pump and hypertension.</p>

Endothelial dysfunction induced by high glucose is associated with decreased ATP-binding cassette transporter G1 expression / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of ATP-binding cassette transporter G1 (ABCG1) in endothelial dysfunction induced by high glucose.</p><p><b>METHODS</b>Human aortic endothelial cells (HAECs) were incubated in the presence of 5.6 or 30 mmol/L glucose for 24-72 h with or without a 2-h pretreatment with the LXR agonist 22(R)-hydroxycholesterol. Real-time PCR and Western blotting were used to measure the mRNA and protein expressions of ABCG1; the intracellular cholesterol efflux and endothelial nitric oxide synthase (eNOS) activity were measured by scintillation counting.</p><p><b>RESULTS</b>High glucose time-dependently suppressed ABCG1 expression and cholesterol efflux to HDL in HAECs. High glucose also decreased eNOS activity. ABCG1 down-regulation induced by high glucose, along with decreased cholesterol efflux and eNOS activity, was abolished by treatment of the cells with the LXR agonist.</p><p><b>CONCLUSION</b>Endothelial dysfunction induced by high glucose is associated with decreased ABCG1 expression.</p>

Prevalence of left ventricular dyssynchrony in patients with heart failure assessed by a novel programmer-cardioGRAF / 老年心脏病学杂志（英文版）

Objectives Left ventricular systolic dyssynchrony is the most important determinant of response to cardiac resynchronization therapy (CRT), playing a vital role to predict improvement of systolic function or LV reverse remodeling. CardioGRAF is a novel programmer based on the ECG gated single photon emission computed tomography (G-SPECT) imaging to detect LV systolic and diastolic dyssynchrony simultaneously. This study was to investigate the prevalence of systolic and diastolic left ventricular (LV) dyssynchrony in patients with heart failure. Methods We retrospectively studied 69 patients with heart disease, including 31 patients who had symptoms of heart failure (NYHA class Ⅱ-Ⅲ), and 38 patients who had no symptoms of heart failure (NYHA class Ⅰ). G-SPECT data were analyzed by cardiaGRAF, and measurements included the time to end systole (TES), the time to peak ejection (TPE), the time to peak filling (TPF), TES+TPF and maximal difference (MD) of each parameters were obtained, using the 95th percentile of the control group as a cutoffof 150 ms for MD-TES, 139 ms for MD-TPE, 345 ms for MD-TPF and 315 ms for MD-TES+TPF. Results The prevalence of LV systolic dyssynchrony was significantly higher in heart failure patients with reduced LV ejection fraction (LVEF)<45% (72% for MD-TES; 64% for MD-TPE) compared with heart failure patients with preserved LVEF=45% (14% for both MD-TES and MD-TPE; P=0.002, P=0.005, respectively); The prevalence of MD-TES<150 ms was higher in NYHA class Ⅲ patients (64%) compared with NYHA class Ⅱ patients (27%, P=0.049). However, the prevalence of the LV diastolic dyssynchrony were high but not difference between NYHA class Ⅲ(47% for both MD-TPF and MD-TES+TPF) and class Ⅲ(63% for MD-TPF; 69% for MD-TES+TPF; P=NS) patients as well as between patients with preserved LVEF (43% for both MD-TPF and MD-TES+TPF) and patients with reduced LVEF(64% for MD-TPF; 72% for MD-TES+TPF; P=NS). Conclusions The prevalence of LV systolic dyssynchrony was high in heart failure patients with reduced LVEF. Diastolic dyssynchrony was common in patients with heart failure. CardioGRAF maybe a useful method to detect LV dyssynchrony.

The treatment of the remnant electrode infection of the permanent pace makers by means of silicone adhesive wrapped and covered the electrodes / 中国介入心脏病学杂志

Objective Treatment remnant electrode infection of permanent cardiac pace makers Methods Remnant electrodes were wrapped in silicone adhesive and covered with skin Results In 16 patients of permanent pace makers with infections of remnant electrodes, by using the method of wrapped and covered electrodes, infection did not occur in the observation of 3 to 24 months Conclusion It is an effective method to treat the infection caused by remnant electrodes of pace makers by means of silicone adhesive wrapping and covering electrodes