木贼麻黄多糖的提取及体外抗氧化活性研究

目的 优化木贼麻黄多糖的提取工艺,初步研究木贼麻黄多糖的体外抗氧化活性。方法 采用热水浸提法提取木贼麻黄多糖,利用单因素试验结合响应面法对提取条件进行优化,并研究木贼麻黄多糖的体外抗氧化活性。结果 木贼麻黄多糖的最佳提取条件为：提取时间2.5 h,提取温度73℃,液料比25∶1,在此条件下多糖提取率为（5.57±0.072）%。木贼麻黄多糖对DPPH自由基和羟基自由基具有较强的清除能力,IC₅₀分别为703.9 μg·mL^-1和2 135.1 μg·mL^-1;对超氧阴离子自由基具有一定的清除能力,对Fe³⁺有一定的还原能力。结论 该提取工艺能较好地提取木贼麻黄多糖,所得木贼麻黄多糖具有一定的体外抗氧化能力,但活性低于同浓度的维生素C。     

HPLC波长切换联合梯度洗脱法同时测定消疲灵颗粒中的7种成分

目的 建立同时测定消疲灵颗粒中7种成分含量的HPLC波长切换联合梯度洗脱方法。方法 采用Venusil MP-C₁₈色谱柱,流动相为乙腈-1%冰醋酸溶液,流速为0.9 mL·min^-1,梯度洗脱,柱温为30 ℃,进样量为10 μL。结果 牡荆素葡萄糖苷、牡荆素鼠李糖苷、牡荆素、金丝桃苷、芒柄花苷、毛蕊异黄酮和芒柄花素检测浓度分别在2.56~51.20 μg·mL^-1,14.87~297.40 μg·mL^-1,2.14~42.80 μg·mL^-1,3.16~63.20 μg·mL^-1,3.80~76.00 μg·mL^-1,2.14~42.80 μg·mL^-1,4.81~ 96.20 μg·mL^-1内与峰面积呈良好的线性关系（r≥0.999 1）,平均回收率97.0%~100.0%,RSD 0.55%~1.67%,精密度和重复性良好,供试品溶液在室温条件下12 h内稳定。结论 该方法操作简便,精密度、稳定性、重复性好,可用于消疲灵颗粒中7种有效成分含量的同时测定。     

白及花与块茎石油醚部位成分分析及其生物活性的比较研究

目的 分析白及花和块茎石油醚部位成分及生物活性。方法 以石油醚（60~90℃）为提取溶剂,采用索氏提取法提取白及花和块茎脂溶性成分,采用GC-MS分析其化学成分,通过滤纸片扩散法、CCK8法和分光光度法分别对其进行抑菌、抗肿瘤和α-淀粉酶抑制作用研究,通过检测DPPH自由基、ABTS自由基和羟自由基的清除率考察其体外抗氧化活性。结果 白及花和块茎中共鉴定出20种石油醚部位成分,其中花11种,块茎19种,共有成分10种,α-乙酰基-γ-丁内酯（15.20%,21.84%）和苄醇（12.07%,24.10%）为主要成分。白及花中石油醚部位成分的抑菌活性高于块茎,对枯草芽孢杆菌效果最好,最小抑菌浓度和最小杀菌浓度分别为0.41,0.51 g·L^-1和0.53,0.66 g·L^-1。当质量浓度为5.0 mg·mL^-1时,白及块茎石油醚部位成分对A₅₄₉细胞的抑制率为29.451%,高于花中石油醚部位成分27.621%的抑制率,前者对α-淀粉酶的IC₅₀为1.819 mg·mL^-1,后者的IC₅₀为2.028 mg·mL^-1。两者对DPPH自由基、ABTS自由基和羟自由基的清除率均随质量浓度的增大而增大,当浓度达到1.0 mg·mL^-1时,前者对ABTS自由基和羟自由基的清除率分别为99.67%和92.22%,高于后者90.07%和38.11%的清除率,后者对DPPH自由基的清除率为31.23%,高于前者18.94%的清除率,两者均低于Vc的清除率。结论 白及花和块茎中石油醚部位成分主要为酯类和醇类,2种石油醚部位成分均具有一定的生物活性,具有潜在的药用价值,并可为白及花的资源开发提供参考。     

3,5-O-二咖啡酰基奎宁酸的稳定性和抗氧化活性研究

目的 考察影响化合物3,5-O-二咖啡酰基奎宁酸稳定性的因素并对3,5-O-二咖啡酰基奎宁酸的体外抗氧化活性进行初步研究。方法 采用HPLC考察3,5-O-二咖啡酰基奎宁酸在不同溶剂、pH、温度、光照条件下的稳定性;采用UV测定3,5-O-二咖啡酰基奎宁酸的体外抗氧化活性（清除DPPH自由基）。结果 溶剂的种类、pH值、温度、光照条件对3,5-O-二咖啡酰基奎宁酸稳定性具有一定影响。3,5-O-二咖啡酰基奎宁酸具有较强的体外清除DPPH自由基活性,其活性与Vc相当[3,5-O-二咖啡酰基奎宁酸和Vc的IC₅₀值分别为（372.56±1.04）μg·mL^-1和（294.54±1.03）μg·mL^-1]。结论 在该化合物的分离纯化及其分析检测时,不能采用纯有机溶剂为溶剂,应在中性或酸性条件下,低温、避光操作。3,5-O-二咖啡酰基奎宁酸作为抗氧化剂在制药、食品、化妆品以及精细化工行业具有广阔的应用前景。     

LC-MS/MS测定阿齐沙坦及其盐在大鼠血浆中的药动学研究

目的 建立液相色谱-串联质谱法测定大鼠血浆中阿齐沙坦及其盐的浓度并研究其药动学。方法 大鼠血浆样本以乙腈沉淀蛋白后,采用Eclipse Plus C₁₈色谱柱（50 mm×3.0 mm,1.8 μm）;流动相（乙腈：水=60：40）,流速为0.35 mL·min^-1,柱温为40℃;采用Agilent 6430三重四极杆串联质谱仪,离子化方式：电喷雾-正离子（API-ES）;监测方式：MRM;阿齐沙坦监测离子对457.3/233.1,缬沙坦监测离子对436.2/291.4,用作内标。SD大鼠灌胃给予阿齐沙坦1.0 mg·kg^-1及阿齐沙坦盐1.2 mg·kg^-1。结果 阿齐沙坦在5~30 000 ng·mL^-1内线性关系良好;回收率为85%~115%,精密度RSD在±15%内。阿齐沙坦盐大鼠体内主要动力学参数如下：AUC_{（0-24 h）}为（12.9±3.2）μg·mL^-1·h^-1,AUC_（0-∞）为（14.2±4.1）μg·mL^-1·h^-1,C_max为（3.8±0.3）μg·mL^-1,T_1/2为（13.4±0.5）h。阿齐沙坦的主要动力学参数如下：AUC_{（0-24 h）}为（8.1±2.6）μg·mL^-1·h^-1,AUC_（0-∞）为（9.7±3.1）μg·mL^-1·h^-1,C_max为（2.3±0.5）μg·mL^-1,T_1/2为（10.5±0.5）h。结论 本法经方法学验证,适用于大鼠血浆中阿齐沙坦及其盐的浓度测定,可用于阿齐沙坦及其盐大鼠体内药动学研究。     

高灵敏度HPLC测定大鼠血浆中益母草碱浓度及其药动学研究

目的 建立一种高灵敏度HPLC测定大鼠血浆中益母草碱浓度,并研究益母草碱在大鼠体内的药动学特征。方法 大鼠口服益母草碱混悬溶液（50 mg·kg^-1）后,不同时间点尾静脉采血,以苯甲酰精氨酸乙酯为内标,血浆样品经酸化后乙酸乙酯萃取,采用HPLC进行测定。色谱条件：采用Diamonsil C₁₈（250 mm×4.6 mm,5 μm）为色谱柱,以乙腈-0.02 mol·L^-1磷酸二氢钾缓冲溶液（pH 3.0）（22：78）为流动相,流速1.0 mL·min^-1,柱温35℃,检测波长277 nm。并利用PKS 1.0软件计算药动学参数。结果 益母草碱血浆浓度在0.05~1.5 μg·mL^-1内线性关系良好（r=0.999 1）。方法的定量下限（LLOQ）为0.05 μg·mL^-1（RSD=12.8%,n=5）;提取回收率为76.5%~82.5%;批内、批间准确度为96.9%~104.9%;日内、日间精密度均<10%;质控样品经反复冻融3次及-20℃放置1个月后均较稳定。大鼠口服益母草碱后,药-时曲线符合二室开放模型,主要药动学参数为t_max=0.95 h,C_max=0.51 μg·mL^-1,t_1/2=3.64 h,AUC_0-t=1.56 μg·mL^-1·h^-1,AUC_0-∞=1.78 μg·mL^-1·h^-1。结论 该方法准确度、灵敏度高,重复性好,可用于生物样品中益母草碱浓度的测定。     

HPLC同时测定双氯芬酸钠滴眼液中3种抑菌剂的含量

目的 建立HPLC同时测定双氯芬酸钠滴眼液中羟苯乙酯、硫柳汞和苯扎氯铵含量的方法。方法 用十八烷基键合硅胶为填充剂,以1%三乙胺溶液（磷酸调节pH值至3.0）为流动相A,以甲醇为流动相B,进行梯度洗脱;流速1.0 mL·min^-1,柱温40℃,检测波长254 nm。结果 羟苯乙酯在20.58~205.8 μg·mL^-1、硫柳汞在8.242~82.42 μg·mL^-1、苯扎氯铵n-C₁₂H₂₅取代物在12.88~128.8 μg·mL^-1、苯扎氯铵n-C₁₄H₂₉取代物在6.624~66.24 μg·mL^-1内线性良好（r≥0.999 8）,平均回收率为99.3%~102.5%（n=9）。结论 该方法简单、准确、重复性好,可用于控制双氯芬酸钠滴眼液中羟苯乙酯、硫柳汞和苯扎氯铵的含量。     

基于斑马鱼的香青兰总黄酮整体发育急性毒性评价研究

目的 利用模式生物斑马鱼研究香青兰总黄酮（TFDM）整体发育急性毒性。方法 采用发育至48 h的斑马鱼暴露于5、10、20、40、42、44、46、48、50、100 μg·mL^-1的TFDM,分别于暴露后24、48 h（24、48 hpe）,计算死亡率、半数死亡浓度（LC₅₀）值;测量每组斑马鱼幼鱼的体长,进行形态学观察并评分;显微镜下观察斑马鱼心脏形态并拍照,记录心率,使用Image-Pro Plus 5.1测量斑马鱼静脉窦-动脉球（SV-BA）距离;显微镜下观察各组斑马鱼是否有体侧水肿来判断TFDM对肾脏的影响并拍照;应用肝脏标记绿色荧光的转基因斑马鱼Tg （L-FABP∶EGFP）,通过检测肝脏荧光强度和面积,观察TFDM对肝脏毒性的影响。结果 TFDM的24 hpe LC₅₀为50 μg·mL^-1,48 hpe LC₅₀为48 μg·mL^-1,100 μg·mL^-1 TFDM组斑马鱼幼鱼全部死亡。与空白对照组比较,20 μg·mL^-1以下的TFDM对斑马鱼的形态和心、肝、肾各脏器无影响;20 μg·mL^-1浓度的TFDM处理斑马鱼48 h导致个别斑马鱼鱼鳔体积减小或缺失,对其他脏器无显著影响;40 μg·mL^-1的TFDM导致斑马鱼出现轻微的心包水肿,处理48 h以后斑马鱼体长显著减小（P＜0.01）,形态评分显著下降（P＜0.01）,斑马鱼的肝脏形态出现轻微变化,但肝脏荧光强度和肝脏荧光面积无显著性变化,对肾脏无影响;暴露在50 μg·mL^-1的TFDM中24 h,斑马鱼出现心包水肿,心率显著下降（P＜0.05）,肝脏荧光强度和面积显著减小（P＜0.05）,肾脏无明显变化。结论 TFDM对斑马鱼的毒性较小,低浓度（≤10 μg·mL^-1）的TFDM对斑马鱼无毒性;中浓度（20 μg·mL^-1）下TFDM对斑马鱼的毒性微弱,仅导致部分斑马鱼鱼鳔体积减小或缺失,对其他各脏器无毒性;高浓度（≥40 μg·mL^-1及以上）下有轻微的心脏毒性和肝脏毒性,在临床应用中有必要合理控制用量。     

LC-MS/MS测定人血清中奥卡西平及其活性代谢产物10-羟基卡马西平的浓度及其临床应用

目的 建立LC-MS/MS同时测定人血清中奥卡西平（oxcarbazepine,OXC）及其活性代谢产物10-羟基卡马西平（10-hydroxycarbamazepine,MHD）的浓度,并将其应用于临床药物浓度检测。方法 血清样本以卡博替尼为内标,乙腈处理后,用LC-MS/MS进行测定。色谱柱为Waters BEH C₁₈（2.1 mm×150mm,1.7 μm）,柱温40℃,流动相为0.1%甲酸和乙腈,流速为0.3 mL·min^-1,进样量1 μL,采用电喷雾正离子多反应监测（MRM）模式检测。OXC及MHD的检测离子对分别为OXC[M-H⁺]m/z 253.2→180.1,MHD[M-H⁺]m/z 255.3→194.2。结果 OXC、MHD血药浓度分别在0.01~1 μg·mL^-1（r²=0.9958）,0.4~40 μg·mL^-1（r²=0.996 2）内线性关系良好,准确度在85%~115%,日内、日间精密度RSD均<15%。OXC、MHD提取回收率分别为90.75%~100.43%,80.40%~82.30%。本方法不受基质效应影响,在室温放置、反复冻融、长期保存下都稳定,RSD均<15%。临床检测60例患者血药浓度,OXC中位值为0.48 μg·mL^-1,MHD中位值为17.1 μg·mL^-1。结论 该方法操作简便快速、准确度高、灵敏度强,适用于对OXC及其活性代谢产物（MHD）的临床血药浓度监测,为个体化给药提供检测技术。     

UHPLC-MS/MS同时检测大鼠血浆中5种CYP450探针药物

目的 采用UHPLC-MS/MS同时检测大鼠血浆中非那西丁、甲苯磺丁脲、奥美拉唑、美托洛尔、咪达唑仑的血药浓度。方法 血浆样品经乙腈沉淀,采用Agilent ZORBAX Eclipse Plus C₁₈色谱柱（2.1 mm×50 mm,1.8 μm）;流动相为乙腈-含0.1%甲酸的水,梯度洗脱,流速为0.4 mL·min^-1。检测采用电喷雾离子源,多反应监测。非那西丁：[M+H]⁺,m/z 180.1→109.9;甲苯磺丁脲：[M+H]⁺,m/z 271.1→91.0;奥美拉唑：[M+H]⁺,m/z 346.1→135.9;美托洛尔：[M+H]⁺,m/z 268.2→115.0;咪达唑仑：[M+H]⁺,m/z 326.1→290.8;内标卡马西平：[M+H]⁺,m/z 237.1→194.0。6只♂ SD大鼠,单剂量口服灌胃10 mg·kg^-1非那西丁,1 mg·kg^-1甲苯磺丁脲,10 mg·kg^-1奥美拉唑,10 mg·kg^-1美托洛尔和10 mg·kg^-1咪达唑仑,分别在给药后多点尾静脉采血。用DAS计算药动学参数。结果 血浆中非那西丁、甲苯磺丁脲、奥美拉唑、美托洛尔和咪达唑仑在各自浓度范围内线性关系良好。日内及日间RSD均<15%,提取回收率>75%,稳定性考察结果良好。非那西丁的AUC_0-t为（5 868.30±2 062.87）ng·mL^-1·h;甲苯磺丁脲的AUC_0-t为（58 056.34±15 569.16）ng·mL^-1·h;奥美拉唑的AUC_0-t为（14 181.67±4 085.40）ng·mL^-1·h;美托洛尔的AUC_0-t为（1 123.67±180.469）ng·mL^-1·h;咪达唑仑的AUC_0-t为（946.91±322.03）ng·mL^-1·h。结论 该方法灵敏度高、操作方便、结果准确,可作为CYP450酶活性及相关研究的测定方法。     

Synthesis and evaluation of 2,6-piperidinedione derivatives as potentially novel compounds with analgesic and other CNS activities

New 2,6-piperidinediones 2_a–g and 4_a–d were prepared by initial condensation of aromatic aldehydes or cycloalkanones with cyanoacetamide to give α-cyanocinnamides l_a–g or cycloalkylidenes 3_a,b which underwent Michae1 addition with ethyl cyanoacetate or diethylmalonate. Compounds 4_a–d were alkylated by various alkyl halides to produce the N-alkylated 2,6-piperidinedione derivatives 5_a–m. Some new selected compounds 2_a–c,f, 4_a–d & 5_e,h,j were pharmacologically evaluated for potential anticonvulsant, sedative and analgesic activities. These compounds exhibited significant anticonvulsant and analgesic effects after a single I.P. administration 100 mg/kg b.wt. . On the other hand all the investigated compounds induced hypnotic activity and prolonged the phenobarbital sodium- induced sleep as compared with the control group and the most potent compound was found to be 2_f.     

NEURAMIDE STIMULATES ADRENOCORTICOTROPIN BUT NOT PROLACTIN RELEASE FROM RAT PITUITARY

Neuramide (NMD), a substance found in crude preparations of porcine stomach extract, is a viral inhibitor that also has putative immunostimulatory effects. The effects of NMD on stress-hormone (ACTH and prolactin—PRL) release were assessed inin vivoandin vitrostudies. In the former, blood levels of corticosterone and PRL were measured in NMD-treated male rats.In vitroexperiments were performed to evaluate the effects of NMD and three of its fractions (obtained with high performance liquid chromatography) on ACTH and PRL release from perfused rat pituitary slices. NMD increased plasma corticosterone levelsin vivoand produced dose-dependent increases inin vitropituitary release of ACTH. No effects on PRL secretion were observedin vivoorin vitro. The stimulatory effects on ACTH release were caused by the NMD fraction with a molecular weight of >5000<10000Da.     

EFFECT OF POLICOSANOL SUCCESSIVE DOSE INCREASES ON PLATELET AGGREGATION IN HEALTHY VOLUNTEERS

Policosanol is a cholesterol-lowering drug with hypocholesterolemic effects demonstrated in experimental models, healthy volunteers and type II hypercholesterolemic patients. In addition, antiplatelet effects of policosanol have been shown in experimental models and healthy volunteers. The effect of successively increasing doses of policosanol on platelet aggregation was investigated in a randomized, placebo-controlled, double-blind study conducted in 37 healthy volunteers. The volunteers were on a placebo-baseline period (two tablets per day) for 7 days and thereafter they received randomly, under double-blind conditions, placebo or policosanol (10mgday⁻¹) for 7 days. After this period dosage was doubled to 20mgday⁻¹for the next 7 days and then again doubled to 40mgday⁻¹, while the control group received placebo tablets all the time. Platelet aggregation as well as coagulation time was measured at baseline and after each dosing step. Results showed that antiplatelet effects of policosanol were successfully enhanced throughout the study, thus suggesting a dose-dependent relationship. No significant effect was reached during the first dosing period, but significant reductions of epinephrine and ADP-induced platelet aggregation were observed after the second one. Finally, a significant inhibition of platelet aggregation induced by all the agonists was observed at the last dosing step. Coagulation time remained unchanged during the trial.     

INDIRECT PARASYMPATHOMIMETIC ACTIVITY OF THE CLASS III ANTIARRHYTHMIC SUBSTANCE / -SOTALOLIN VITRO: REVERSIBLE INHIBITION OF CHOLINESTERASE ISOENZYMES FROM BLOOD AND THE HUMAN CENTRAL NERVOUS SYSTEM

Inhibitory effects of the class III antiarrhythmic compound / -sotalol on acetylcholinesterase (AChE; EC 3.1.1.7) isoenzymes of both erythrocytes and the human caudate nucleus and on serum cholinesterase (ChE; EC 3.1.1.8) were studiedin vitrousing a spectrophotometric kinetic assay with acetylthiocholine (ASCh) as substrate. Sotalol concentrations in the assays varied from 0.32 to 3.2m . All isoenzymes studied were inhibited by / -sotalol in a reversible and concentration-dependent manner. Double reciprocal plots of the reaction velocity against varying ASCh concentrations revealed that / -sotalol reduced substrate affinity (apparent Michaelis constant, KM, increased) of serum ChE, but did not change the enzyme's maximal rate of ASCh hydrolysis (V_max). Thus, / -sotalol inhibition of serum ChE was of the competitive type (rate constant for reversible competitive inhibition: K_i=0.51m ). In contrast, / sotalol reduced the maximal reaction velocity of the AChE isoenzyme from the central nervous system (caudate nucleus), but had no influence on substrate affinity of the enzyme (K_Mwith ASCh unchanged) indicating purely non-competitive inhibition kinetics (rate constant of reversible non-competitive inhibition: K_i′=0.44m ). / -sotalol inhibition of erythrocyte AChE was of mixed competitive/non-competitive type (K_i=0.31m , K_i′=0.49m ). Non-competitive / -sotalol inhibition of caudate nucleus AChE and the non-competitive component of erythrocyte AChE inhibition cannot be overcome by increased concentrations of the cholinergic transmitter acetylcholine (ACh). Peak / -sotalol plasma levels as described in the literature for both humans (15μ ) and experimental animals (dogs: 18μ ; rats: 260μ ) as well as maximal myocardial concentrations of the substance (dogs: 46μ ; rats: 478μ ) are in the range of about 2% to 100% of the sotalol inhibition rate constants determined in the present paper for cholinesterase isoenzymesin vitro. Thus, / -sotalol inhibition of ACh hydrolysisin vivomay contribute to both the well known antiarrhythmic potential and proarrhythmic side effects of the compound.     

鼻渊净胶囊的HPLC指纹图谱研究

目的 建立鼻渊净胶囊的高效液相色谱（HPLC）指纹图谱。方法 采用Agilent SB-C₁₈（4.6 mm×250 mm,5 μm）色谱柱,乙腈-水为流动相、以1.0 ml/min流速行梯度洗脱,检测波长210 nm,柱温30 ℃,洗脱时间为80 min。采用中药色谱指纹图谱相似度评价系统（2004A版）对检测出色谱进行指纹图谱相似度评价。结果 建立了鼻渊净胶囊的HPLC指纹图谱,确定了20个共有峰,15个峰归属到各药材,其中5个峰确认了化学成分;10批样品的指纹图谱的整体相似度与对照图谱比较,均在90%以上。结论 所建立的鼻渊净胶囊指纹图谱有助于从整体上控制该制剂的质量。     

Investigation of the prevalence of tetQ, tetX and tetX1 genes in Bacteroides strains with elevated tigecycline minimum inhibitory concentrations

In this study, the antibiotic susceptibilities to tigecycline and tetracycline of 35 selected Bacteroides fragilis group strains were determined by Etest, and the presence of tetQ, tetX, tetX1 and ermF genes was investigated by polymerase chain reaction (PCR). tetQ was detected in all 12 B. fragilis group isolates (100%) exhibiting elevated tigecycline minimum inhibitory concentrations (MICs) (≥8 μg/mL) as well as the 8 strains (100%) with a tigecycline MIC of 4 μg/mL, whilst tetX and tetX1 were present in 15% and 75% of these strains, respectively. All of these strains were fully resistant to tetracycline (MIC ≥ 16 μg/mL). On the other hand, amongst the group of strains with tigecycline MICs < 4 μg/mL (15 isolates), tetQ, tetX and tetX1 were found less frequently (73.3%, 13.3% and 46.7%, respectively). All but two strains harbouring the tetQ gene in this group were non-susceptible to tetracycline, with a MIC > 4 μg/mL. These data suggest that in most cases tigecycline overcomes the tetracycline resistance mechanisms frequently observed in Bacteroides strains. However, the presence of tetX and tetX1 genes in some of the strains exhibiting elevated MICs for tigecycline draws attention to the possible development and spread of resistance to this antibiotic agent amongst Bacteroides strains. The common occurrence of ermF, tetX, tetX1 and tetQ genes together predicted the presence of the CTnDOT-like Bacteroides conjugative transposon in this collection of Bacteroides strains.     

AMELIORIATION OF CHEMICALLY-INDUCED HEPATOCYTE INJURY BY CYCLOSPORINE A

Cyclosporine A, beside its current applications, possesses potential hepatoprotective effects. This study was directed to investigate the effect of Cyclosporine A pretreatment on hepatic injury due to carbon tetrachloride (CCl₄) and -galactosamine. Rats were injected by two successive doses of Cyclosporine A (5mgkg⁻¹day⁻¹). Six hours after the second dose, 1mlkg⁻¹of CCl₄was administered i.p. Effects associated with Cyclosporine A pretreatment were examined by using isolated hepatocytes and hepatocytes that were immobilized and continuously perfused. -Galactosamine (5m ) was added directly to the perfusion medium. After isolation, hepatocytes were examined histologically by light and electron microscopy, immobilized and perfused for further metabolic functional activity evaluation. Cyclosporine A pretreatmentin vivoproduced hepatoameliorative effects of various degrees which were statistically significant as manifested by: (1) an increased trypan blue exclusion after CCl₄; (2) an improved ureagenesis after CCl₄; (3) a reduction in the lipid droplets accumulation in the cytoplasm produced by CCl₄administration; (4) well preserved cytoplasmic organelles as mitochondria, endoplasmic reticulum ER, nuclear chromatin structures that were altered by CCl₄; and (5) an increased hepatocytes survival in the agarose gel matrix, reduction of LD leakage and improvement of ureagenesis after -galactosamine addition to the perfusion medium. The beneficial effect of Cyclosporine A pretreatment in modifying hepatotoxicity of chemical insults merits further studies.     

喙果黑面神化学成分研究

目的研究大戟科植物喙果黑面神(Breynia rostrata Merr.)的化学成分。方法利用硅胶、凝胶等色谱技术分离纯化化学成分,根据化合物的理化性质和光谱数据进行结构鉴定。结果从喙果黑面神的正丁醇萃取部分分离得到4个化合物,分别鉴定为6-O-甲基丙酰基-α-D-吡喃葡糖(6-O-methylpropanoyl-α-D-glucopyranose,1);4″-苯酚基-6-O-甲基丙酰基-β-D-吡喃葡糖苷(4″-phenolic-6-O-methylpropanoyl-β-D-glucopyranoside,2);1-O-没食子酰基-β-D-吡喃葡糖苷(1-O-galloyl-β-D-glucopyranoside,3);熊果苷(arbutin,4)。结论化合物1和2为新化合物,3和4均为首次从该种植物分离得到。     

EFFECTS OF 2-GUANIDINE-4-METHYLQUINAZOLINE ON GASTRIC ACID SECRETION IN RATS

In this study 2-guanidine-4-methylquinazoline (2-GMQ) appeared to decrease basal and stimulated gastric acid secretion, while structurally related compounds as dimethyl- biguanide, cyanoguanidine and 2-cyanoamino-4-methylpyrymidine did not. Thus, there is an antisecretory effect when the biguanide group is associated with a lipophilic structure. The antisecretive effects exerted by 2-GMQ are associated with anti H₂-histamine activity.The anti H₂-histamine nature of the effects of 2-GMQ was confirmed by the capacity of this compound of depressing the chronotropic activity of the isolated guinea pig auricle increased by histamine, as well as relaxant activity in rat uterus contracted by histamine, since both preparations are rich in H₂-histamine receptors.     

Effect of bay K 8644, a calcium channel agonist,on dog cardiac muscarinic receptors

To investigate further whether the effects of the dihydropyridine (DHP) drugs on calcium channels are related to those of these drugs on muscarinic receptors, the binding characteristics of the DHP calcium channel agonist, Bay K 8644, on muscarinic receptors and calcium channels were compared to those of the DHP calcium channel antagonists, nicardipine and nimodipine in the dog cardiac sarcolemma. Bay K 8644, nicardipine and nimodipine inhibited the specific [³H]QNB binding with K _i values of 16.7μM, 3.5μM and 15.5μM respectively. Saturation data of [³H]QNB binding in the presence of these DHP drugs showed this inhibition to be competitive. Bay K 8644, like nicardipine and nimodipine, blocked the binding of [³H]nitrendipine to the high affinity DHP binding sites, but atropine did not, indicating that the muscarinic receptors and the DHP binding sites on calcium channels are distinct. The K _i value of Bay K 8644 for the DHP binding sites was 4 nM. Nicardipine and nimodipine (K _i :0.1–0.2 nM) were at least 20 times more potent than Bay K 8644 in inhibiting [³H]nitrendipine binding. Thus, the muscarinic receptors were about 4000 times less sensitive than these high affinity DHP binding sites to Bay K 8644. These results suggest that the DHP calcium agonist Bay K 8644 binds directly to the muscarinic receptors but its interaction with the muscarinic receptors is not related to its binding to the DHP binding sites on calcium channels.