不同粒径的水飞蓟素固体脂质纳米粒口服吸收比较研究

目的:考察不同粒径的固体脂质纳米粒对大鼠口服吸收水飞蓟素的影响。方法:以山榆酸甘油酯为载体材料,分别制备了150,500,1 000 nm 3种粒径的水飞蓟素固体脂质纳米粒,给大鼠灌胃后,采用RP-HPLC测定不同时间点血药浓度,数据经3p97软件进行处理。结果:口服150 nm水飞蓟素固体脂质纳米粒后的AUC分别是500,1 000 nm的2.08,2.54倍(P<0.05),这表明150 nm固体脂质纳米粒的生物利用度明显高于其他2种制剂。结论:固体脂质纳米粒粒径对水飞蓟素的口服吸收有着显著影响。     

Anticonvulsant efficacy of topiramate in phenytoin-resistant kindled rats

PURPOSE: We evaluated the anticonvulsant efficacy of topiramate (TPM), a structurally novel antiepileptic drug (AED), in amygdala kindled rats that had been preselected with respect to their response to phenytoin (PHT). METHODS: Anticonvulsant response was tested by determining the afterdischarge threshold (ADT; i.e., a sensitive measure for drug effects on focal seizure activity). By repeated testing with the PHT prodrug fosphenytoin (FOS) three groups of kindled rats were separated: rats in which consistent anticonvulsant effects were obtained (PHT responders), rats that showed no anticonvulsant response (PHT nonresponders), and rats with variable responses (variable PHT responders). The latter, largest group was used to evaluate at which doses and pretreatment times TPM exerted significant anticonvulsant effects on ADT. For this purpose, TPM was tested at four doses (20, 40, 80, 160 mg/kg i.p.) and two pretreatment times (1 and 4 h). The most effective treatment protocol was then used for TPM testing in PHT responders and nonresponders. RESULTS: TPM proved to be an effective AED in the kindling model. At 40 mg/kg, significant ADT increases were obtained after both 1 and 4 h after administration. In addition to the effect on focal seizure threshold, seizure severity and duration recorded at ADT were decreased by TPM, indicating that this drug acts on both seizure threshold and seizure spread. In PHT nonresponders, TPM significantly increased ADT, which is in line with its proven efficacy in patients with refractory partial epilepsy in whom phenytoin has failed. However, TPM was more efficacious in increasing ADT in PHT responders than in nonresponders, substantiating that the difference between these groups of kindled rats extends to other AEDs. Repeated testing of kindled rats with TPM indicated that, similar to PHT, there are individual kindled rats without anticonvulsant response to TPM (i.e., TPM nonresponders). CONCLUSIONS: The data of this study substantiate that PHT nonresponders are a unique model for the search of new AEDs with improved efficacy in refractory partial epilepsy.     

Opposite effects of glutamate antagonists and antiparkinsonian drugs on the activities of DOPA decarboxylase and 5-HTP decarboxylase in the rat brain

This study measured the activities of L-DOPA and 5-HTP decarboxylase (DDC and 5-HTPDC) in the substantia nigra and corpus striatum of reserpine-treated rats. Acute injection of the NMDA receptor antagonists CGP 40116 (5 mg/kg) and HA 966 (5 mg/kg), and to a lesser extent eliprodil (10 mg/kg), greatly elevated DDC in both structures, whilst having no effect on (nigra) or inhibiting (striatum) 5-HTPDC. L-DOPA (25 mg/kg) on its own inhibited both enzymes in either brain region. The weak NMDA receptor-channel blockers (and antiparkinsonian drugs) budipine (10 mg/kg), memantine (40 mg/kg) and amantadine (40 mg/kg) strongly increased DDC, whilst not affecting or decreasing 5-HTPDC activity in nigra and striatum. The L-DOPA-induced suppression of DDC was mostly reversed by all three antiparkinsonian drugs, whilst L-DOPA-induced inhibition of 5-HTPDC was only reversed by CGP 40116 (striatum only). It is concluded that glutamate exerts a differential physiological influence on the biosynthesis of dopamine and 5-HT in the brain, by tonically suppressing DDC and tonically stimulating 5-HTPDC. The L-DOPA-induced reduction in DDC may help to explain the eventual loss of efficacy of L-DOPA therapy in parkinsonian patients. It is suggested, however, that it may be possible to extend the lifetime of L-DOPA therapy with drugs which potentiate the activity of DDC, such as budipine and the 1-aminoadamantanes.     

缺氧对血管内皮生长因子诱导主动脉内皮细胞通透性增加的调控研究

目的 :为了解缺氧对血管内皮生长因子 (VEGF)增强血管内皮细胞通透性作用的影响 ,考察正常和缺氧状态下VEGF对体外培养牛主动脉内皮细胞 (BAEC)脂蛋白通透性的影响及银杏叶提取物 (Egb76 1)的抑制作用。方法 :将VEGF及Egb76 1加入BAEC共孵育 ,用SN 6 95型液闪计数器测 [12 5I]氧化低密度脂蛋白( [12 5I]OxLDL)通过BAEC的百分率。结果 :VEGF可显著增强BAEC对 [12 5I]OxLDL的通透性 (P <0 .0 1) ,这种增加具有浓度依赖性。缺氧 3h可促进VEGF所致的的通透性增加。Egb76 1能显著抑制VEGF诱导的通透性升高 (P <0 .0 1)。结论 :VEGF在动脉粥样硬化的形成和发展过程中起一定作用。Egb76 1对VEGF诱导血管内皮通透性升高有显著的抑制作用。     

抗高血压新药美林洛尔在大鼠体内的药代动力学和生物利用度

目的建立测定美林洛尔血药浓度的方法,探讨美林洛尔在大鼠体内的药代动力学及生物利用度。方法灌胃和静脉给予大鼠美林洛尔5 mg/kg,采用颈动脉取血并用高效液相-荧光法测定血浆中美林洛尔浓度,应用3P87药动学程序对血药浓度数据进行拟合,计算药代动力学参数,评价其绝对生物利用度。结果美林洛尔在0.02~3.00μg/ml浓度范围内与样品峰面积/内标峰面积呈良好线性关系,其相关系数r=0.9999。提取平均回收率大于80%,日内、日间RSD<10%。大鼠静脉注射美林洛尔后体内药动学符合开放双室模型,其分布相和消除相的半衰期分别为(4.22±5.58)min和(58.53±17.60)min。曲线下面积、中央室分布容积和血浆清除率分别为(133.40±9.27)(μg.min)/ml、(0.27±0.15)L/kg和(7.50±0.53)ml/(g.min)。灌胃给药符合开放单室模型,其达峰时间、最大血药浓度和药时曲线下面积分别为(14.29±3.28)min、(0.64±0.11)μg/ml和(54.35±9.34)(μg.min)/ml。结论建立的高效液相-荧光法专属性强、灵敏度高,可用于美林洛尔的体内定量分析。美林洛尔在大鼠体内的绝对生物利用度为40.74%。     

化合物Ib对阿霉素肾病大鼠干预效果的实验研究

目的了解血管紧张素受体拮抗剂化合物Ib对大鼠阿霉素肾病综合征病理及相关临床指标的干预作用及可能机制。方法采用阿霉素肾病(AN)模型,将70只大鼠分为阿霉素肾病组、化合物Ib(5 mg/kg,10 mg/kg,20 mg/kg)组和坎地沙坦酯治疗组,检测大鼠给予药物治疗后24 h尿蛋白排泄量、血清总蛋白、白蛋白及总胆固醇等血生化指标变化,并设正常对照组。结果化合物Ib(5 mg/kg,10 mg/kg,20 mg/kg)可明显降低造模大鼠24 h尿蛋白含量,增加血总蛋白及白蛋白含量,降低总胆固醇含量。结论化合物Ib对阿霉素肾病大鼠的肾脏具有保护效应,减轻肾损伤,降低蛋白尿。     

补骨脂素对HL60/HT耐药细胞的逆转作用及对细胞内钙离子浓度的影响

目的研究补骨脂素对HL60/HT耐药细胞的逆转作用及对耐药细胞内Ca2 浓度的影响,探讨其可能的作用机制。方法采用MTT法测定补骨脂素对细胞增殖的抑制作用,高效液相色谱法检测细胞内三尖杉酯碱(HT)的量,激光共聚焦显微镜测定细胞内不同时段和不同时间点的Ca2 浓度。结果补骨脂素在1~20μmol/L能不同程度降低HT对HL60/HT细胞的IC50,并不同程度提高细胞内HT的量;1~20μmol/L补骨脂素作用不同时段(24、48、96h),HL60/HT细胞内Ca2 浓度与作用时间成负相关,10和20μmol/L补骨脂素作用HL60/HT不同时间(5、10、15、20、25min),细胞内Ca2 浓度与作用成负相关性。结论补骨脂素能逆转HL60/HT细胞的多药耐药,其作用机制与影响耐药细胞内Ca2 浓度、增加细胞内HT的量有关。     

2-羟丙基-β-环糊精对大蒜油溶解度及稳定性的影响

目的考察2-羟丙基-β-环糊精(HP--βCD)对大蒜油溶解度及稳定性的影响。方法采用GC法测定大蒜油中大蒜素,以大蒜素为指标,测定其在不同质量浓度HP--βCD水溶液中的溶解度,比较大蒜油HP--βCD包合物水溶液与大蒜油聚山梨酯-80水溶液对热和光的稳定性。考察不同pH值、抗氧剂、氮气及灭菌等对5%HP--βCD水溶液中大蒜油中大蒜素的稳定性的影响。结果HP--βCD可显著增加大蒜油中大蒜素在水中的溶解度,并且随着HP--βCD质量浓度的增加,大蒜素的溶解度呈线性增加;在pH值为5.0时,大蒜油HP--βCD包合物水溶液具有较高的稳定性,充氮可增加其稳定性,抗氧剂的加入以及热、光均会加速大蒜素的分解;大蒜油HP--βCD包合物水溶液中大蒜素的稳定性显著高于大蒜油聚山梨酯-80水溶液的稳定性。结论HP--βCD对大蒜油中的大蒜素具有显著的增溶作用,可提高大蒜油的稳定性。     

青黛散抗溃疡性结肠炎的作用研究

目的：探讨青黛散抗实验性溃疡性结肠炎的作用。方法：采用三硝基苯磺酸法制备大鼠溃疡性结肠炎模型，HE染色制作病理切片，对其抗实验性溃疡性结肠炎作用进行评价。结果：病理组织学检查表明青黛散有效改善了溃疡性结肠炎。结论：青黛散可有效对抗实验性结肠性溃疡炎。