Effect of shenmai injection on L-type calcium channel of diaphragmatic muscle cells in rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the effect of Shenmai Injection (SMI) on L-type calcium channel of diaphragmatic muscle cells in rats.</p><p><b>METHODS</b>Single diaphragmatic muscle cell of rats was obtained by the acute enzyme isolation method and the standard whole-cell patch clamp technique was used to record the inward peak L-type calcium current (IPLC) and current-voltage relationship curve of diaphragmatic muscle cells of 7 rats, and to compare the effects of SMI in various concentrations on them.</p><p><b>RESULTS</b>When keeping the electric potential at -80 mV, stimulation frequency 0.5 Hz, clamp time 300 ms, stepped voltage 10 mV, and depolarized to +60 mV, 10 microliters/ml of SMI could only cause the mean IPLC of rat's diaphragmatic muscle cells increased from -6.9 +/- 0.6 pA/pF to -7.5 +/- 0.7 pA/pF, the amplification being (9.2 +/- 2.8)%, comparison between those of pre-treatment and post-treatment showed insignificant difference. But when the concentration of SMI increased to 50 microliters/ml and 100 microliters/ml, the mean IPLC increased to -8.4 +/- 0.6 pA/pF and -9.2 +/- 0.6 pA/pF, respectively, and the amplification was (22.4 +/- 1.7)% and (34.6 +/- 4.6)% respectively, showing significant difference to that of pre-treatment (P < 0.05). However, SMI showed no significant effect on maximal activation potential and reversal potential.</p><p><b>CONCLUSION</b>SMI can activate the calcium channel of diaphragmatic muscle cells in rats, increase the influx of Ca2+, so as to strengthen the contraction of diaphragmatic muscle, which may be one of the ionic channel mechanisms of SMI in treating diaphragmatic muscle fatigue in clinical practice.</p>

Effect of shenmai injection and aminophylline on small airway smooth muscle cell apoptosis and related gene expression in rats with emphysema / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the effect of Shenmai Injection (SMI) and aminophylline on small airway smooth muscle cell (SASMC) apoptosis and the Fas/FasL expression in the papain induced emphysema model rats.</p><p><b>METHODS</b>Emphysema model in rat was established by a single intratracheal instillation of papain. Apoptosis and Fas/FasL expression of SASMC were examined by immunohistochemical SABC and TUNEL assay at 1, 3, 5, 7, 15 and 30 days after modelling, and the effect of SMI and aminophylline on them were observed.</p><p><b>RESULTS</b>Fas, FasL expressions in normal SASMC were very low with a positive rate of (2.31 +/- 0.05)% and (1.28 +/- 0.47)% respectively. After papain instillation, the positive rates increased along with the prolonging of instillation time. SMI showed an inhibition on SASMC Fas and FasL expression but aminophylline didn't show. SASMC apoptosis was very low in normal rats with a rate of (0.87 +/- 0.32)%, it also raised after papain instillation and increased progressively along with the instillation time. SMI treatment could lower the apoptosis rate but aminophylline couldn't.</p><p><b>CONCLUSION</b>Fas and FasL participated the SASMC apoptosis modulation in emphysema formation. SMI shows a definite treatment effect on emphysema by influencing the Fas and FasL protein expression and reducing SASMC apoptosis through inhibiting the release of inflammatory mediator.</p>