Effects of docosahexaenoic acid on ion channels of rat coronary artery smooth muscle cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effects of docosahexaenoic acid (DHA) on large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels and voltage-dependent K(+) (K(V)) channels in rat coronary artery smooth muscle cells (CASMCs), and evaluate the vasorelaxation mechanisms of DHA.</p><p><b>METHODS</b>BK(Ca) and K(V) currents in individual CASMC were recorded by patch-clamp technique in whole-cell configuration. Effects of DHA at various concentrations (0, 10, 20, 40, 60 and 80 µmol/L) on BK(Ca) and K(V) channels were observed.</p><p><b>RESULTS</b>(1) DHA enhanced IBK(Ca) and BK(Ca) tail currents in a concentration-dependent manner while did not affect the stably activated curves of IBK(Ca). IBK(Ca) current densities were (68.2 ± 22.8), (72.4 ± 24.5), (120.4 ± 37.9), (237.5 ± 53.2), (323.6 ± 74.8) and (370.6 ± 88.2)pA/pF respectively (P < 0.05, n = 30) with the addition of 0, 10, 20, 40, 60 and 80 µmol/L DHA concentration, and half-effect concentration (EC(50)) of DHA was (36.22 ± 2.17)µmol/L. (2) IK(V) and K(V) tail currents were gradually reduced, stably activated curves of IK(V) were shift to the right, and stably inactivated curves were shifted to the left in the presence of DHA. IK(V) current densities were (43.9 ± 2.3), (43.8 ± 2.3), (42.9 ± 2.0), (32.3 ± 1.9), (11.7 ± 1.5) and (9.6 ± 1.2)pA/pF respectively(P < 0.05, n = 30)post treatment with 0, 10, 20, 40, 60 and 80 µmol/L DHA under manding potential equal to +50 mV, and EC(50) of DHA was (44.19 ± 0.63)µmol/L.</p><p><b>CONCLUSION</b>DHA can activate BK(Ca) channels and block K(V) channels in rat CASMCs, the combined effects on BK(Ca) and K(V) channels lead to the vasodilation effects of DHA on vascular smooth muscle cells.</p>

Effect of acupuncture on regulating skeletal muscle endurance in rats / 中国针灸

<p><b>OBJECTIVE</b>To study the effect of acupuncture on skeletal muscle endurance in rats as a pre-games assistant training.</p><p><b>METHODS</b>Thirty male SD rats were randomly divided into 3 groups: control, model and acupuncture group. Acupuncture group was treated at "Dazhui" (GV 14), "Housanli" (ST 36) by twisting mild reinforcing-reducing method for 20 min, no interventions were added on control and model group. Muscle strength was detected in three groups under anaesthetic (after model established in model group, after model established and treated in acupuncture group). Averaged change percentage of mean skeletal muscle endurance (P(m)) and averaged maximum percentage of skeletal muscle endurance (P(max)) were evaluated.</p><p><b>RESULTS</b>(1) 10P(m) in model group decreased more than acupuncture group statistically (P < 0.05); 20P(m), 30P(m) and 40P(m) in model group decreased significantly compared to those in control group and acupuncture group (P < 0.05, P < 0.01). (2) Changes of 10P(max) in acupuncture group was much less than in model group (P < 0.05); changes of 20P(max), 30P(max), 40P(max) and 50P(max) decreased more in model group than in acupuncture group and control group (P < 0.01, P < 0.05).</p><p><b>CONCLUSION</b>As an assistant training method, acupuncture can postpone descending point of muscle strength endurance to delay sport fatigue.</p>

Research on compound electroacupuncture waveforms by microcomputer control / 中国针灸

Reviewing the development and the current situation of electroacupuncture, the deficiencies and shortcomings of electroacupuncture instrument applied in clinic and laboratory are analyzed. It is proposed that compound electroacupuncture waveform is an inevitable trend for electroacupuncture technique development. Based on the clinic and experiment needs, three different waveforms are taken as the model of compound electroacupuncture waveforms. Controlled by the microcomputer technique, the compound electroacupuncture waveforms are more multiple and precise, which will expand the range of application of electroacupuncture.

Echocardiographic standardized myocardial segmentation features in patients with left ventricular noncompaction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To analyze the echocardiographic standardized myocardial segmentation features in patients with left ventricular noncompaction (LVNC).</p><p><b>METHODS</b>Echocardiographic characteristics of 9 patients with LVNC were analyzed and the localization of lesions were determined according to the standardized myocardial segmentation (SMS) recommended by American Heart Association (AHA).</p><p><b>RESULTS</b>Loose trabeculation in the myocardial lesions were evidenced in all LVNC patients. Communication between deep intertrabecular recess and LV cavity was evident with color flow imaging. According to SMS of AHA, noncompaction of ventricular myocardium was localized in apical segment in all 9 patients, in apical segment of the inferior wall (IW) in 9 patients, in apical segment of the lateral wall (LW) in 7 patients, in middle segment (MS) of IW in 7 patients, in MS of LW in 6 patients. One NC segment was also evidenced in apical segment and MS of septal ventricular wall, basal segment of IW and LW and right ventricular apex, respectively. NC was not found in left ventricular anterior wall.</p><p><b>CONCLUSION</b>Echocardiographic standardized myocardial segmentation is helpful to diagnose LVNC and NC was mostly localized in the apical segments of LVNC patients.</p>