洛伐他汀对低密度脂蛋白损伤血管内皮的保护作用

目的：探讨洛伐他汀对低密度脂蛋白所致血管内皮功能损伤的保护作用及可能的机制．方法：一次性从大鼠舌下静脉注射天然低密度脂蛋白(n-LDL 4mg／kg),在舌下静脉注射n-LDL之前大鼠腹腔注射洛伐他汀(2或4mg／kg),每天一次,连续五天．注射n-LDL后48小时检测乙酰胆碱诱导的血管内皮依赖性舒张(EDR)及血清一氧化氮(N0)、丙二醛(MDA)的含量和超氧化物歧化酶(SOD)的活性．结果：一次注射n-LDL导致了EDR、血清NO水平及SOD活性明显降低,MDA的浓度明显增高。预先给予洛伐他汀能明显减轻LDL引起的EDR的抑制和血清NO水平及SOD活性的降低,减少MDA的生成,左旋硝基精氨酸(L-NNA)减弱洛伐他汀对血管内皮的保护作用．结论：洛伐他汀对LDL损伤的血管内皮具有保护作用,可能与保护内皮依赖性松弛因子和抗氧化作用有关。     

Lovastatin-induced Apoptosis of Human Medulloblastoma Cell Lines in vitro

Medulloblastoma is a malignant paediatric central nervous system tumor with a poor prognosis, stimulating the evaluation of improved treatment strategies. Lovastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, is currently used to treat patients with hypercholesterolemia. This compound also inhibits the production of non-steroidal mevalonate derivatives that are implicated in the control of cellular proliferation, and can induce cell-cycle arrest in vitro. We recently showed that lovastatin inhibited growth and promoted apoptosis of neuroblastoma, the peripheral nervous system cousin of medulloblastoma. Therefore the potential of lovastatin as a possible anticancer drug against medulloblastoma was evaluated in vitro. Four medulloblastoma cell lines, Daoy, UW228, D341 Med and D283 Med, were treated with 1–40µM of lovastatin in vitro. Analysis of cell morphologic changes, cell viability, DNA fragmentation and flow cytometry in all four cell lines showed growth inhibition and induction of apoptosis with lovastatin treatment. As little as 10µM of lovastatin was sufficient to cause a marked reduction in cell numbers, and more than 20µM of lovastatin induced >90% cells to undergo apoptosis, after intervals ranging between 36 and 96h, depending on the cell line. Lovastatin induced apoptosis in these cell lines was concomitant with cell cycle arrest in G1. The attached cell lines UW228 and Daoy were more sensitive to lovastatin than D283 Med and D341 Med. Daoy cells which survived several cycles of lovastatin treatment could still be induced to undergo apoptosis after longer treatment times. The efficient induction of apoptosis by lovastatin favours this drug as a potential new avenue of therapeutic intervention for medulloablastoma.     

中药红曲的生药学及质量控制标准的研究

目的：建立中药红曲的质量控制方法。方法：对中药红曲进行显微鉴定,采用薄层色谱法进行定性鉴别,并采用高效液相色谱法对红曲所含主要有效成分洛伐他汀（ｌｏｖａｓｔａｔｉｎ）进行含量测定。结果：显微镜下可见红曲样品粉末中含有大量菌丝及孢子,红曲的薄层色谱中在与对照品洛伐他汀色谱相应的位置上有一斑点,采用高效液相色谱法,洛伐他汀在５～１００μｇ／ｍｌ线性关系良好,加样回收率为９６．４％（ＲＳＤ＝３．６８％,ｎ＝５）。结论：方法准确、简便、灵敏,为红曲的质量评价和质量控制提供了依据。     

Possible association of QTc interval prolongation with co-administration of quetiapine and lovastatin.

BACKGROUND: QTc interval prolongation can occur as a result of treatment with both conventional and novel antipsychotic medications and is of clinical concern because of its association with the potentially fatal ventricular arrhythmia, torsade de pointes. METHODS: One case is described in which a patient with schizophrenia, who was being treated for dyslipidemia, developed a prolonged QTc interval while taking quetiapine and lovastatin. RESULTS: QTc returned to baseline when the lovastatin dose was reduced. CONCLUSIONS: QTc prolongation associated with antipsychotic medication occurs in a dose-dependent manner. We therefore hypothesize that the addition of lovastatin caused an increase in plasma quetiapine levels through competitive inhibition of the cytochrome P(450) (CYP) isoenzyme 3A4. Our case highlights the potential for a drug interaction between quetiapine and lovastatin leading to QTc prolongation during the management of dysipidemia in patients with schizophrenia.     

洛伐他汀对糖尿病大鼠肾功能及肾脏组织p38丝裂原激活蛋白激酶表达的影响

目的 探讨洛伐他汀对糖尿病(DM)大鼠肾小球结构、功能及肾组织p38丝裂原活化蛋白激酶(MAPK)及其下游转录因子cAMP反应元件结合蛋白(cREB)表达的影响。方法 18只雄性Wistar大鼠行右肾切除术2周后,随机分为3组:右肾切除对照组、DM组和洛伐他汀治疗组每组6只。DM组和洛伐他汀组腹腔注射链脲佐菌素(STZ,65 mg／kg)诱发DM模型,洛伐他汀组制模后1 d每日给予洛伐他汀20 mg／kg灌胃。分别于注射STZ后4周收集大鼠尿液,测定尿蛋白(Upro)、尿肌酐(UCr);股动脉放血分离血清,测定血糖(Glu)、血肌酐(SCr)、尿素氮(BUN)、胆固醇(CHO)和甘油三酯(TG),并计算肌酐清除率(CCr)。免疫组化检测肾皮质磷酸化p38 MAPK(P-p38 MAPK)及磷酸化CREB(P-CREB)的表达特征,并检测转化生长因子-β1(TGF-β1)、纤维粘连蛋白(FN)及层粘连蛋白(LN)的表达,应用图像分析系统进行定量分析。流式细胞术检测P-p38 MAPK和P-CREB蛋白的表达,Western印迹法检测肾皮质P-p38 MAPK和P-CREB活性的变化。结果 与对照组相比,4周时DM组P-p38 MAPK、P-CREB、TGF-β1、FN及LN表达均明显升高(P均<0.01);而与DM组相比,洛伐他汀组各指标的表达有不同程度的降低(P均<0.01)。结论 洛伐他汀对DM大鼠肾脏结构和功能具有保护作用,可能通过调节p38 MAPK和CREB蛋白的表达     

Local low‐dose lovastatin delivery improves the bone‐healing defect caused by Nf1 loss of function in osteoblasts

Postfracture tibial nonunion (pseudoarthrosis) leads to lifelong disability in patients with neurofibromatosis type I (NF1), a disorder caused by mutations in the NF1 gene. To determine the contribution of NF1 in bone healing, we assessed bone healing in the Nf1 conditional mouse model lacking Nf1 specifically in osteoblasts. A closed distal tibia fracture protocol and a longitudinal study design were used. During the 21‐ to 28‐day postfracture period, callus volume, as expected, decreased in wild‐type but not in Nf1 mice, suggesting delayed healing. At these two time points, bone volume (BV/TV) and volumetric bone mineral density (vBMD) measured by 3D micro–computed tomography were decreased in Nf1 callus‐bridging cortices and trabecular compartments compared with wild‐type controls. Histomorphometric analyses revealed the presence of cartilaginous remnants, a high amount of osteoid, and increased osteoclast surfaces in Nf1 calluses 21 days after fracture, which was accompanied by increased expression of osteopontin, Rankl, and Tgfβ. Callus strength measured by three‐point bending 28 days after fracture was reduced in Nf1 versus wild‐type calluses. Importantly, from a clinical point of view, this defect of callus maturation and strength could be ameliorated by local delivery of low‐dose lovastatin microparticles, which successfully decreased osteoid volume and cartilaginous remnant number and increased callus BV/TV and strength in mutant mice. These results thus indicate that the dysfunctions caused by loss of Nf1 in osteoblasts impair callus maturation and weaken callus mechanical properties and suggest that local delivery of low‐dose lovastatin may improve bone healing in NF1 patients. © 2010 American Society for Bone and Mineral Research     

脂必泰胶囊中红曲的含量测定

目的建立测定脂必泰胶囊红曲中洛伐他汀含量的高效液相色谱法。方法色谱柱为Dionex C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-水(75∶25),流速为1 mL/min,柱温为22℃,检测波长为236 nm,进样量为10μL。样品以75%乙醇超声提取10 min后进样测定,定量方法采用峰面积外标法。结果洛伐他汀质量浓度在0.011 83～0.473 2 g/L范围内与峰面积积分值线性关系良好(r=0.999 9),方法平均回收率为99.07%,RSD=1.77%(n=6)。结论该方法简单、快速、准确,适用于测定脂必泰胶囊红曲中洛伐他汀的含量。     

洛伐他汀与二氢吡啶类药物相互作用研究

目的研究5种二氢吡啶类药物对洛伐他汀代谢的影响。方法采用大鼠肝微粒体体外代谢模型,洛伐他汀分别与不同浓度的硝苯地平、非洛地平、拉西地平、乐卡地平和尼莫地平置于一定量的鼠肝微粒体中,于37℃预孵5min后．加β—NADP／NADPH的0．1％NaHC03溶液启动反应,并开始记时,37℃下孵育20min后,加入一定量冰乙腈沉淀蛋白并终止反应,高速离心后,上清液进HPLC分析,并分别计算硝苯地平、非洛地平、拉西地平、乐卡地平和尼莫地平对洛伐他汀代谢抑制IC50值。结果不同结构的二氢吡啶类药物对洛伐他汀代谢的影响亦不同,其中硝苯地平的抑制作用最小（IC50值为53．98umol·L-1）,尼莫地平的抑制作用最大（IC50值为2．01umol·L-1）,通过结构参数分析表明油水分配系数（LogP）对抑制作用影响较大成正相关,而分子量、表面积亦对抑制作用产生影响,成负相关。结论对于患有高血压合并血脂异常的患者联合使用二氢吡啶类降压药与洛伐他汀时,产生药物相互作用的可能性较大。为避免不良反应发生．宜选用LogP值较大,而分子量、表面积较小的硝苯地平和非洛地平等。