血脂调节剂的研究——Ⅰ.HMG-CoA还原酶抑制剂M-8614A及MH-2688B产生菌的筛选

利用酶联免疫吸附测定法,酶标β-羟基β-甲基-戊二酸单酰铺酶A(HMG-CoA)还原酶抑制剂Compactin抗体,定向筛选血脂调节剂。从青霉M-8614菌株发酵液中分离到M-8614A。该物质理化性质及波谱解释表明与Mevastatin为同一物质。 M-8614菌株用亚硝酸盐等诱变剂处理,从诱变株MH-2688发酵液中分离到MH-2688B。该物质理化性质及波谱解释表明与Lovastatin为同一物质。     

RP—HPLC测定人血浆中洛伐他汀浓度及药动学研究

用ＲＰ－ＨＰＬＣ测定人血浆中洛伐他汀浓度。以甲醇－水（８３∶１７，Ｖ／Ｖ）为流动相，色谱柱采用ＨＹＰＥＲＳＩＬＢＤＳ－Ｃ１８（５μｍ）不锈钢柱，紫外２３７ｎｍ波长检测。血浆样品经环己烷－异丙醇（９５∶５）萃取浓缩后进样测定。洛伐他汀浓度在２．５～８０ｎｇ／ｍｌ范围内线性良好，ｒ＝０．９９６８。测定含洛伐他汀２０．０ｎｇ／ｍｌ的血浆样品，其日内（ｎ＝７）及日间（ｎ＝７）的ＲＳＤ分别为９．８％和８．５％。回收率平均为（１０１．３±５．５）％。测定了１０名健康志愿者单次ｐｏ洛伐他汀片剂８０ｍｇ后不同时间的血药浓度，计算了相应的药动学参数。     

Variable activation of lovastatin by hydrolytic enzymes in human plasma and liver

Lovastatin, widely used to lower cholesterol, is a pro-drug that requires metabolic activation through hydrolysis by carboxyesterases. There appear to be at least three distinct esterases in humans capable of catalysing this reaction, one in plasma and two in the liver.The rate of lovastatin hydroxy acid formation was measured as 15.8 pmol · ml^–1 · min^–1 in plasma, 2.13 pmol · mg^–1 protein · min^–1 in hepatic microsomes and 0.92 pmol · mg^–1 protein · min^–1 in cytosol. The data suggest that on average the three esterases together are capable of activating about 220 nmol (90 g) lovastatin per minute per person, to which the esterases of plasma, liver microsomes and liver cytosol contribute approximately 18, 15 and 67%, respectively.All three esterases showed evidence of inter-individual variability. In one of 17 livers, both cytosolic and microsomal esterase activity was completely missing, while two other liver specimens lacked one esterase.Such variability must be expected to influence the therapeutic efficacy of the drug, and they might be related to its occasional toxicity.     

洛伐他汀对ⅡB型高脂血症患者血脂、血糖及胰岛素代谢的影响

作者观察了３０例ⅡＢ型高脂血症患者在给予洛伐他汀口服８周前后血脂、血糖及胰岛素的变化。发现用药８周后ＴＣ及ＬＤＬ－Ｃ明显降低（Ｐ＜ ０．０５）,ＴＧ、ＨＤＬ－Ｃ、ＶＬＤＬ－Ｃ变化不大（Ｐ＞ ０．０５）。空腹血糖（ＦＰＧ）及服糖后２小时血糖（２ｈＰＧ）较用药前升高（前者Ｐ＜ ０．０５）。空腹胰岛素（ＦＰＩ）及服糖后２ 小时胰岛素（２ｈＰＩ）也较治前增高（后者Ｐ＜ ０．０５）。空腹血糖与空腹胰岛素乘积的倒数〔（１／（ＦＰＧ×ＦＰＩ）〕,差异无统计学意义。而餐后２小时血糖与餐后２ 小时胰岛素乘积的倒数〔１／（２ｈＰＧ×２ｈＰＩ）〕,差异有统计学意义。可认为长期使用该药,对２Ｂ型高脂血症患者有可能导致高胰岛素血症,值得进一步探讨。     

高效液相同时测定保健食品中两种结构形式洛伐他汀的含量

目的：建立保健食品中同时测定两种结构形式洛伐他汀含量的方法。方法：用高效液相色谱法同时测定含保健食品中两种结构形式洛伐他汀的含量。结果：方法线性范围为：0．500～0．025μg，最低检出限为0．001μg，总分析时间11min。洛伐他汀平均保留时间：闭环型9．632min，开环型8．682min。4种浓度的平均回收率为：97．77％。结论：高效液相色谱法同时测定洛伐他汀浓度稳定、可靠、简便，适用于保健食品的分析。     

洛伐他汀经PI3K/Akt和ERK1/2信号通路抑制大鼠骨髓间充质干细胞凋亡

目的 体外以缺氧无血清条件模拟心肌梗死后的心脏缺血微环境,研究洛伐他汀能否抑制缺氧无血清引起的骨髓间充质干细胞(MSC)凋亡并探讨其机制.方法 以Hocchst33342染色荧光显微镜观察法及Annexin V/PI流式细胞术检测洛伐他汀的抗凋亡作用,并进一步采用Westernblot方法 检测洛伐他汀对线粒体凋亡途径的抑制作用以及对磷脂酰肌醇3激酶(PI3K)/丝氨酸苏氨酸激酶(Akt)途径和丝裂原活化的蛋白激酶(MAPK)的激酶(MEK)/细胞内信号调节蛋白激酶(ERK1/2)途径的激活作用.结果 0.01～1 μmol/L浓度范围的洛伐他汀能够有效地抑制缺氧无血清引起的MSC凋亡.洛伐他汀抑制线粒体凋亡途径,洛伐他汀抑制细胞色素C释放,降低天冬氨酸特异性半胱氨酸蛋白酶-3(caspase-3)活化,从而保护线粒体功能.洛伐他汀的抗凋亡效应以及其抑制细胞色素C释放的作用均可被PI3K抑制剂LY294002和MEK抑制剂U0126阻断.洛伐他汀能够激活PI3K/Akt和MEK/ERK1/2两条细胞存活信号通路,分别导致Akt和GSK-3β及ERK1/2磷酸化.结论 洛伐他汀能够抑制线粒体凋亡途径,并激活PI3K/Akt和MEK/ERK1/2细胞存活通路,最终发挥抗缺氧无血清引起的MSC凋亡.该研究为提高移植干细胞的存活率提供了一种可能有效的干预措施.     

洛伐他汀促进颌面部骨折愈合过程中BMP-2表达的研究

目的探讨洛伐他汀促进颌骨骨折愈合过程中对骨形成蛋白-2（BMP-2）的影响。方法健康家兔24只,于颌骨制造骨折模型,再随机分为给药组和对照组,每组12只,给药组手术次日给予10mg/（kg·d）洛伐他汀灌胃,疗程为28天,对照组给予安慰剂。利用RT-PCR及Western blot检测骨折愈合过程中给药组和对照组骨折后3、7、10、14、21和28天骨痂中BMP-2的表达,同时应用ELISA检测血清中BMP-2的含量。结果 RT-PCR结果显示,给药组BMP-2基因表达高峰出现在第7天,对照组出现在第14天,且峰值较低。同时Western blot结果显示,术后7~14天骨痂中BMP-2蛋白给药组明显高于对照组,术后21~28天给药组与对照组没有明显差异。血清学检测两组BMP-2升高,在术后14天含量达到高峰,且给药组明显高于对照组（P〈0.05）。结论洛伐他汀明显促进颌骨骨折愈合过程中BMP-2的合成与分泌,进而有利于骨折的愈合。     

急性冠脉综合征血清白介素1β浓度的变化及洛伐他汀治疗的影响

目的:探讨白介素-1β(IL-1β)在急性冠脉综合征(ACS)发病中的作用,以及他汀类药物在ACS治疗中的抗炎作用。方法:75名ACS患者随机分为A、B、C三组,每组25人。A组为常规治疗组,B组为常规治疗 洛伐他汀20mg／d,C组为常规治疗 洛伐他汀40mg／d。均随访2周。以稳定性心绞痛(SAP)患者(n=25)为对照组。于治疗前、后分别测定血清IL-1β,并分析IL-1β与冠心病其他危险因素(TG、LDL-C)的相关性。结果:ACS组血清IL-1β水平明显高于SAP组(P<0．001),B、C组洛伐他汀早期干预治疗后血清IL-1β水平明显下降(P< 0．01),且呈剂量依赖性,而与TG、LDL-C下降无相关性。A组治疗前后无明显变化。结论:炎症反应是导致ACS 发生的原因之一,洛伐他汀治疗可显著降低ACS患者IL-1β水平,且与血脂的下降不相关,说明具有独立于降脂的抗炎作用。     

银杏达莫联合洛伐他汀治疗急性脑梗塞80例临床观察

目的:评价银杏达莫联合洛伐他汀治疗急性脑梗塞的临床疗效。方法:确诊脑梗塞患者80例,随机分为治疗组和对照组各40例,对照组给予银杏达莫注射液15mL/次,1次/天静滴;治疗组在对照组用药基础上加用洛伐他汀20毫克,1次/天口服。两组患者分别治疗14天后评价临床疗效,神经功能缺损血小板聚集功能指标和生活能力评定指标。结果:治疗组和对照组总有效率分别为92.5%和82.5%,两组组间比较具有显著性差异(P0.05);神经功能缺损程度评分治疗前后比较具有非常显著性差异(P0.01),治疗后组间比较具有显著性差异(P0.05);两组患者治疗后日常生活能力改善率分别为89.2%和59.4%,组间比较具有非常显著性差异(P0.01)。结论:银杏达莫注射液联合洛伐他汀治疗急性脑梗塞疗效确切。     

Lovastatin controls signal transduction in vascular smooth muscle cells by modulating phosphorylation levels of mevalonate-independent pathways

Lovastatin has been proven to effectively lower circulating LDL cholesterol and to exert antiproliferative effects on various cell lines, the latter effect being only incompletely understood. We found that lovastatin modulates the signal transducing phosphorylation cascade in vascular smooth muscle cells in a mevalonate-independent manner. Lovastatin was found to distinctively increase total phosphotyrosine levels in smooth muscle cells, an effect which could not be restored by mevalonate. At a concentration of 5 μmol/L lovastatin had a highly specific effect on the mitogen-activated protein kinase pathway. The expression of p42/44 mitogen-activated protein kinase (MAPK) was clearly reduced, but could be restored by addition of mevalonate, while the phosphorylation of p44 was mildly suppressed and the phosphorylation of p42 MAPK was reduced to non-detectable levels. While the phosphorylation of p44 MAPK could partially be restored by addition of mevalonate, the reduced phosphorylation of p42 MAPK could not be restored by addition of excessive doses of mevalonate or stimulation of the cells with basic fibroblast growth factor. Concurrently the expression of the GTP-binding Ras protein was significantly elevated at 5 and 20 μmol/L lovastatin, this effect being attenuated by addition of mevalonate to cell cultures. The data indicate that lovastatin is capable of modulating cellular signaling independently of the cholesterol synthesis pathway. Received: 30 August 2000, Returned for 1. revision: 20 September 2000, 1. Revision received: 14 November 2000, Returned for 2. revision: 28 November 2000, 2. Revision received: 11 December 2000, Accepted: 12 December 2000