The present study was designed to study the difference effects between nicardipine and its twoenantiomers on thoracic artery of rabbit. A high-performance liquid chromatographic methodwas used to prepare the two enantiomers of nicardipine. The thoracic artery of rabbit wasremoved. The vessels were cut into 3 mm in width and 15 mm in length spiral strips andimmersed into tissue baths. The concentration-response curves of nicardipine and its enantiomerswere obtained by cumulative administration of the vasoconstrictors. Nicardipine and theenantiomers could shift the dose-response curves of NE, KCl or CaCl2 to right in a nonparallelmanner and decrease the maximum effective in a concentration-depended manner, respectively.The pD2' value of R-(-)-nicardipine showed significantly effective than that of nicardipineand S-(+)-nicardipine (P<0.01). There was not obviouse difference between the pD2' value ofnicardipine and S-(+)-nicardipine (P>0.05). The results demonstrate that the stereoselectiveinteraction between R-(-)-nicardipine and L-calcium channel receptor is more stronger thanthat of S-(+)-nicardipine.

Effective components, ligustilide and butylidenephthalide, from Ligusticum Chuanxiong (Ligusticum wallichii Franchat, Umbelliferae) werescreened and identified by using a cell membrane chromatography (CMC) and a gas chromatography/mass spectrometry (GC/MS). Thecomponents showed the effects of inhibiting vasoconstriction in vitro on rat abdominal aorta segments. The screening procedure was performed ina rat artery CMC column (50mm×2.0mm I.D.) with a sodium phosphate buffer (pH 7.4) as mobile phase at 37℃. The identification wasaccomplished by a DB-5MS 30m capillary column (0.25 mm I.D., 0.25 Am film thickness) with helium as carrier gas operating under programcontrol temperature and electron impact ionization mass spectrometer in a scan mode. Results demonstrated that ligustilide andbutylidenephthalide can act on rat artery cell membrane similar to verapamil in CMC system. They significantly inhibited the vasoconstrictionsinduced by norepinephrine bitartrate (NE) and calcium chloride (CaCl2). The relaxing effect of ligustilide on the NE-and CaCl2-inducedconstrictions is more potent than that of butylidenephthalide. Ligustilide and butylidenephthalide seem to be the two main effective components ofLigusticum Chuanxiong as a traditional Chinese medicine for treating blood vessel diseases.

A monolithic molecularly imprinted polymer (mMIP) with specific recognition ability forstrychnine was prepared by in-situ polymerization, using methacrylic acid (MAA) as a functionalmonomer, ethylene glycol dimethacrylate (EDMA) as a cross-linking agent, toluene anddodecanol as porogenic solvents and 2, 2￠-azobisisobutyronitrile (AIBN) as a initiator. Scanningelectron microscopy and mercury intrusion porosimetry were used to identify the structuralfeatures of the mMIP. The results show that there were three kinds of pore structures. The largethrough-pore structure allows mobile phase to flow through a column of mMIP with a low backpressure and the other pores lead to the molecular recognition. Some chromatographic conditionssuch as the pH and the composition of the mobile phase were characterized. Strychninewas separated from compounds such as indole, quinine and brucine. The possible recognitionmechanisms were ionic and hydrogen bonding interactions between the strychnine moleculeand the mMIP.