This article introduces the independent experiment and social investigation activities in the course of medication analy- sis set up for strengthening students' comprehensive abilities.These activities create a good study atmosphere for enhancing stu- dents' ability to do research and their humanistic qualities.

Acetaminophen ; metabolism ; Animals ; Cells, Cultured ; Drug Interactions ; Flavonoids ; metabolism ; Hepatocytes ; metabolism ; Humans

To establish single- and double-transfected transgenic cells stably expressing hMATE1, hMATE1 cDNA was cloned by RT-PCR from human cryopreserved kidney tissue, and subcloned into pcDNA3.1(+) plasmid by virtue of both HindIII and Kpn I restriction enzyme sites. Subsequently, the recombined pcDNA3.1(+)- hMATE1 plasmid was transfected into MDCK, MDCK-hOCT1 or MDCK-hOCT2 cells using Lipofectamine 2000 Reagent. After a 14-day-cultivation with hygromycin B at the concentration of 400 µg · mL(-1), all clones were screened with DAPI and MPP+ as substrates to identify the best candidate. The mRNA content of hMATE1, the cellular accumulation of metformin with or without cimetidine as inhibitor, or transportation of cimetidine was further valuated. The results showed that all of the three cell models over expressed hMATE1 mRNA. The cellular accumulation of metformin in MDCK-hMATE1 was 17.6 folds of the control cell, which was significantly inhibited by 100 µmol · L(-1) cimetidine. The transcellular transport parameter net efflux ratios of cimetidine across MDCK-hOCT1/hMATE1 and MDCK-hOCT2/hMATE1 monolayer were 17.5 and 3.65, respectively. In conclusion, cell models with good hMATE1 function have been established successfully, which can be applied to study the drug transport or drug-drug interaction involving hMATE1 alone or together with hOCT1/2 in vitro.
Animals ; Biological Transport ; Cimetidine ; pharmacology ; DNA, Complementary ; Dogs ; Drug Interactions ; Humans ; Madin Darby Canine Kidney Cells ; Metformin ; pharmacology ; Organic Cation Transport Proteins ; genetics ; metabolism ; Transfection

AIMTo search for flavonoids which possess stronger vasorelaxation action.

METHODSFour quercetin glycosides (1a - d) were synthesized from quercetin in three steps i. e. selective protection of quercetin, condensation with corresponding acetyiglycosyl bromide, and then removal of the protecting group; Six flavone compounds (2a - f) were prepared from phloroglucinol according to the conventional methods; The structures of synthetic compounds were confirmed by IR, 1H NMR, 13C NMR and MS. Vasorelaxation action of ten synthetic quercetin derivatives (or analogues) and four natural flavonoids compounds were examined on the isolated rat thoracic aorta rings; Comparative octanol-water partition coefficients (logP) were measured using a reversed-phase HPLC method.

RESULTSMost of the tested flavonoids showed concentration dependent relaxation effects against PE-induced contractions of rat aortic rings. These compounds had stronger action with the augment of logP values.

CONCLUSIONCompound 3-bromo-5 ,7-dihydroxyflavone (2d) was identified to have the most potent vasodilating action. These compounds exert vasodilating effects that are related to the logP values. A structure-activity relationship of flavonoids was suggested.

Animals ; Aorta, Thoracic ; drug effects ; Dose-Response Relationship, Drug ; Flavonoids ; chemical synthesis ; chemistry ; pharmacology ; Male ; Molecular Conformation ; Molecular Structure ; Quercetin ; administration & dosage ; analogs & derivatives ; chemical synthesis ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Structure-Activity Relationship ; Vasodilation ; drug effects ; Vasodilator Agents ; administration & dosage ; chemical synthesis ; pharmacology

OBJECTIVETo observe the content variation of luteolin and luteolin-7-beta-D-glucoside in Chrysanthemum morifolium Ramat. (CMR) from different collection time.

METHODSRP-HPLC was used to analyze these two components in CMR collected in 2001 and 2002.

RESULTThe content of luteolin was significantly lower than that of luteolin-7-beta-D-glucoside. Furthermore, the former showed no marked changes during collection, while the latter did not varied markedly in early collection but decreased significantly in later collection.

CONCLUSIONThe content of luteolin-7-beta-D-glucoside reflects the quality of Chrysanthemum morifolium Ramat. more viably than that of luteolin.

Chromatography, High Pressure Liquid ; Chrysanthemum ; chemistry ; Flavonoids ; analysis ; Glucosides ; analysis ; Luteolin

OBJECTIVETo determine the possible difference in vasodialtation effect of quercetin and rutin.

METHODSThe isolated rat thoracic aorta was treated with phenylephrine (PE), and the effects of quercetin and rutin on the preconstricted aorta rings with or without endothelium were determined by organ bath technique. Nitric oxide synthase inhibitor L-N(G)-nitroarginine methyl-ester (L-NAME), guanylyl cyclase inhibitor methylene blue, cyclooxygenase inhibitor indomethacin were used to explore the mechanism.

RESULTSQuercetin (10-160 micromol/L) caused vasorelaxation of aorta rings preconstricted with PE in endothelium-intact and denuded aorta rings in a dose-dependent manner. Rutin(10-160 micromol/L) caused dose-dependent vasorelaxation in endothelium-intact rings preconstricted with phenylephrine, but not in denuded aorta rings. The maximal response (Rmax) values calculated from vasorelaxation curves of quercetin and rutin were (77.20+/-6.11)% and (44.28+/-7.48)%, respectively. There was no difference between median effective concentration (EC(50)) values of quercetin and rutin. Pretreatment with L-NAME (0.1 mmol/L) abolished the vasorelaxation by rutin,but did not influence the vasodilating effect of quercetin in endothelium-intact rings. Pretreatment with methylene blue (10 mmol/L) canceled the vasorelaxation both by quercetin and rutin. Pretreatment with indomethacin (10 micromol/L) attenuated the vasodilatation of quercetin, but did not affect the vascular effect of rutin.

CONCLUSIONThe vasodilatation effect of quercetin is more potent than rutin. The vasodilatation effect of quercetin might be mediated by guanylyl cyclase and cyclooxygenase-dependent pathway, while the vasodilatation by rutin might be via nitric oxide-guanylyl cyclase pathway.

Animals ; Aorta, Thoracic ; drug effects ; Dose-Response Relationship, Drug ; Guanylate Cyclase ; metabolism ; In Vitro Techniques ; Male ; Nitric Oxide ; metabolism ; Phenylephrine ; pharmacology ; Prostaglandin-Endoperoxide Synthases ; metabolism ; Quercetin ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Rutin ; pharmacology ; Vasodilator Agents ; pharmacology

OBJECTIVETo determine the effects of Varglaucocalyx on c-fos gene expression during global myocardial ischemia-reperfusion.

METHODForty Wistar rats were divided into 5 groups: group N as control; group CN as ischemia-reperfusion control and group XH, XM and XL treated with Varglaucocalyx 5%, 1%, 0.5% respectively prior to ischemia-reperfusion. The isolated rat hearts were perfused in condition of constant temperature and pressure, and then the left ventricular myocardiums were extracted for use. The expression of c-fos protein was detected by immunochemical method. The expression of c-fos protein were quantified by using computer image analysis system.

RESULTCompared with the values of group N, protein expressions relative area of c-fos gene (PERA) were increased significantly in group CN, XH, XM, XL(P < 0.01), but decreased significantly in group XH, XM, XL, compared with those of group CN (P < 0.05). The PERA of c-fos gene in group XM, XL were significantly lower than in group XH (P < 0.01), and the PERA of c-fos gene in group XM were lower than in group XL(P < 0.05).

CONCLUSIONVarglaucocalyx can effectively depress the expression of c-fos gene in myocardium which may account for its protection against myocardial ischemia-reperfusion injury, and the middle and the low concentrations of Varglaucocalyx are more effective than the high concentrations.

Animals ; Cardiotonic Agents ; pharmacology ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Gene Expression Regulation ; drug effects ; Genes, fos ; Isodon ; chemistry ; Male ; Myocardial Reperfusion Injury ; etiology ; metabolism ; Myocardium ; metabolism ; Plants, Medicinal ; chemistry ; Proto-Oncogene Proteins c-fos ; biosynthesis ; Random Allocation ; Rats ; Rats, Wistar

To investigate the difference in absorptive of tetrahydropalmatine (THP) and l-tetrahydropalmatine (l-THP) in rat intestine as well as the mechanism of the absorption of THP, in situ single pass perfusion model was used and the concentration of THP in perfusate was determined by HPLC. The absorption rate constant (k(a)) and effective permeability values (P(eff)) of THP had no significant difference (P > 0.05) at concentration of 8, 16 and 32 microg x mL(-1) in perfusion or in four different regions of intestine of rat (duodenum, jejunum, ileum, colon). The absorption of l-THP and THP in jejunum had significant difference (P < 0.05). The k(a) and P(eff) of THP increased obviously when verapamil was co-perfused with THP, while those of l-THP were not influenced by verapamil. The absorption of THP in intestine showed the passive diffusion process, and without a special absorption region. The stereoselective absorption difference may result from stereoselective combination of P-glycoprotein with d-THP.
ATP-Binding Cassette, Sub-Family B, Member 1 ; antagonists & inhibitors ; Animals ; Berberine Alkaloids ; chemistry ; pharmacokinetics ; Colon ; metabolism ; Duodenum ; metabolism ; Female ; Ileum ; metabolism ; Intestinal Absorption ; drug effects ; Jejunum ; metabolism ; Male ; Perfusion ; Permeability ; Rats ; Rats, Sprague-Dawley ; Sex Factors ; Stereoisomerism ; Verapamil ; pharmacology

OBJECTIVETo investigate the vascular activity of extract from mulberry leaves (EML) on rat thoracic aorta and the underlying mechanism.

METHODSIsolated thoracic rings of Sprague-Dawley rats were mounted on the organ bath and the tension of the vessel was recorded.

RESULT(1) EML produced a concentration-dependent vasorelaxation of aorta preconstricted by high K(+) (60 mmol/L) or 10(-6) mol/L phenylephrine (PE) in endothelium-intact and endothelium-denuded arteries. (2) EML at EC(50) concentration reduced the calcium dose-response curve. (3) After incubation of aorta with verapamil, EML induced vasocontraction of aorta preconstricted by PE, which was abolished by ruthenium red.

CONCLUSIONThe vascular effect of EML is biphasic, the vasorelaxation is greater than the vasocontraction. The vasorelaxation induced by EML may be mediated by inhibition of voltage-and receptor-dependent calcium channels in vascular smooth muscle cells, while the vasocontraction is via activation of ryanodine receptor in endoplasmic reticulum.

Acetates ; isolation & purification ; pharmacology ; Animals ; Aorta, Thoracic ; drug effects ; physiology ; Dose-Response Relationship, Drug ; In Vitro Techniques ; Male ; Morus ; chemistry ; Plant Extracts ; isolation & purification ; pharmacology ; Plant Leaves ; chemistry ; Potassium ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Ryanodine Receptor Calcium Release Channel ; physiology ; Vasoconstriction ; drug effects ; Vasodilation ; drug effects

Objective To evaluate the role of late course accelerated fractions.ted irradiation(LCAF) combined with concurrent chemotherapy in the management of esophageal carcinoma.Methods From March 1998 to July 2000,111 eligible patients were randomized into LCAF alone group(LCAF,57 patients)or LCAF plus concurrent chemotherapy group(LACF-CT,54 patients).The radiotherapy regimen was identical in the two groups,consisting of conventional fractionation in the first 2/3 course and accelerated fractionation in the second 1/ 3 course to a total dose of 68.4 Gy/41 Fx/44 d.Chemotherapy regimen consisted of four eycles of cisplatin 25 mg/ (m~2?d)plus fluorouracil 600 mg/(m~2?d)on day 1 to 3 every 4 weeks and was delivered on the first day of radiotherapy.Results The median follow-up time was 67.1 months(range 47.6-76.4 months).The 1-,3-,5- year survival rate was 67%,44% ,40% and 77%,39% 28% in LACF-CF and LEAF group,respectively(P =0.310).Grade 3+4 acute side-effact was 42% and 25% in LCAF-CT and LCAF group,respectively(P＜0. 05),with 3 treatment-related deaths in the LCAF-CT group.Conclusions Late course accelerated fractionated irradiation combined with concurrent chemotherapy has a trend towards improving the survival,at the cost of increasing acute side-effect.Its role needs further confirmation by larger sample studied in randomization.