Determination of Schaftoside in Jinshaniu Huashi Tablets by HPLC / 中国药师

Objective:To establish an HPLC method to determine the content of schaftoside in Jinshaniu Huashi tablets .Meth-ods:The separation was performed on an Agilent ZORBAX SB-C18 column(150 mm ×4.6 mm, 5 μm)with 0.2% phosphoric acid-acetonitrile as the mobile phase with gradient elution at a flow rate of 1.0 ml· min-1 .The detection wavelength was set at 272 nm, and the column temperature was set at 25 ℃.Results: The calibration curve of schaftoside had a good linearity within the range of 4.58-183.15 μg· ml-1(r=1.000 0).The average recovery was 99.65%with RSD of 1.09%(n=6).Conclusion:The established method is simple and accurate with high repeatability , which can be used for the content determination of schaftoside in Jinshaniu Hua-shi tablets .

Role of unsaturated fatty acids in the enhancement of muscarinic current by hyposmotic membrane stretch in guinea pig smooth muscle cells / 生理学报

To investigate the function of exogenous unsaturated fatty acids in hyposmotic membrane stretch enhancement of muscarinic current (ICCh) in antral circular smooth muscle cells of guinea pig, we recorded the membrane current with the conventional whole cell patch-clamp technique. I(CCh) elicited by 50 micromol/L carbachol (CCh) at the holding potential of 20 mV under isosmotic condition was taken as control. Hyposmotic membrane stretch increased I(CCh) to 226.0+/-21.0%. When the cells were pretreated with 5 micromol/L arachidonic acid (AA), linoleic acid (LA) or oleic acid (OA), I(CCh)was inhibited to 3.8+/-0.6%, 35.2+/-0.8% and 66.6+/-0.6% respectively. Hyposmotic membrane stretch increased I(CCh) to 106.0+/-2.5%, 173.2+/-6.8% and 222.1+/-11.0% of the control respectively. Five micromol/L AA inhibited hyposmotic membrane stretch-enhanced I(CCh) by 51.2+/-3.8%, while the control I(CCh) under isosmotic condition was inhibited by 96.2+/-1.6%. The results suggest that unsaturated fatty acids inhibited I(CCh) and the inhibitory effect is more significant when the unsaturation degree is increased. However, the unsaturated fatty acids are not involved in the increase of I(CCh) induced by hyposmotic membrane stretch.

Role of actin microfilament in hyposmotic membrane stretch-induced increase in muscarinic current of guinea-pig gastric myocytes / 生理学报

To investigate the relationship between cytoskeleton and hyposmotic membrane stretch-induced increase in muscarinic current, the role of actin microfilament in hyposmotic membrane stretch-induced increase in muscarinic current was studied with the whole-cell patch clamp technique in guinea-pig gastric myocytes. In this study, the muscarinic current was induced by carbachol (50 micromol/L) or GTPgammaS (0.5 mmol/L). The results showed that hyposmotic superfusate (202 mOsmol/L) increased carbachol-induced current (I(CCh)) by 145+/-27% and increased GTPgammaS-induced current by 183+/-30%; but in the presence of cytochalasin-B (Cyt-B, 20 micromol/L), an actin cytoskeleton disruptor, hyposmotic membrane stretch increased I(CCh) by 70+/-6%. However, hyposmotic membrane stretch induced increase in I(CCh) was potentiated to 545+/-81% by phalloidin (20 micromol/L), an actin microfilament stabilizer. The results demonstrated that hyposmotic membrane stretch increased the muscarinic currents induced by carbachol or GTPgammaS and that the actin microfilament is involved in the process in guinea-pig gastric myocytes.