脂欣康胶囊对载脂蛋白E基因敲除小鼠TNF-α、IL-1β干预作用

目的观察脂欣康胶囊对载脂蛋白E（ApoE）基因敲除小鼠血清肿瘤坏死因子α（TNF-α）和白细胞介素1β（IL-1β）的影响。方法将6周龄ApoE基因敲除小鼠随机分为模型组与脂欣康组，相同遗传背景的同龄正常C57BL／6J小鼠为正常对照组。脂欣康组灌服脂欣康胶囊内之药粉，模型组、正常对照组均灌服生理盐水。连续灌胃2周后（8周龄），各组随机取出半数小鼠，雌雄各半。麻醉后由腹腔静脉抽血。另一部分继续灌胃4周后（12周龄）由腹腔静脉抽血。离心分离血清，ELISA法检测TNF-α和IL-1β结果灌服2周后，脂欣康组小鼠血清TNF-α和IL-1β显著低于模型组（P〈0．05），模型组显著高于正常对照组（P〈0．05）；继续用药4周后，TNF-α和IL-1β无明显增高，脂欣康组显著低于模型组（P〈0.05），模型组显著高于正常对照组（P〈0．05）。结论脂欣康胶囊具有显著抑制ApoE基因敲除小鼠血清TNF-α与IL-1β增高的作用。     

脂欣康对轻度认知功能障碍病人的干预效果评价

目的 观察脂欣康胶囊改善认知功能的疗效,探讨其潜在作用机制.方法 以老年轻度认知功能障碍(MCI)病人为观察对象,给予脂欣康胶囊和/或维生素E治疗,采用神经心理检测量表评估病人的认知功能,采集病人治疗前后的外周血标本进行血脂检测.结果 脂欣康组病人认知功能与血脂明显改善,而维生素E组未见明显变化.结论 脂欣康能够改善MCI病人的认知功能,其作用机制与改善脂质代谢、降低血黏度有关.     

莱菔硫烷对阿尔茨海默病模型小鼠认知功能的干预作用

目的探讨莱菔硫烷(SFN)对阿尔茨海默病(AD)模型小鼠认知功能的影响。方法健康成年C57BL/6小鼠,按体重随机分为3组,每组10只,雌雄各半。模型组与干预组小鼠连续13 w喂饲含铝水(铝浓度0.4 g/100 ml),并隔日1次皮下注射200 mg/kg D-半乳糖;同时干预组小鼠每日1次灌胃给予25 mg/kg SFN,模型组小鼠灌胃等量蒸馏水,并设立溶媒对照组。通过Morris水迷宫和旷场实验检测小鼠的神经行为学改变,采用尼氏染色方法观察小鼠海马CA1区细胞形态及数量的变化,运用透射电镜观察小鼠海马CA1区细胞超微结构的改变。结果水迷宫实验结果显示,模型组小鼠逃避潜伏期与对照组相比明显延长,穿越圆台所在位置的次数明显少于对照组(P0.05);干预组小鼠与模型组相比,逃避潜伏期缩短,穿越圆台所在位置的次数增多(P0.05)。旷场实验结果表明,模型组小鼠与对照组相比,跨格数减少,中央格停留时间明显延长(P0.05);而干预组小鼠与模型组相比,跨格次数明显增加(P0.05)。尼氏染色结果发现模型组小鼠海马CA1区神经细胞数量明显降低,细胞排列散乱,而干预组小鼠海马CA1区神经细胞同模型组相比数量较多,并且细胞排列较为整齐紧密。电镜结果显示模型组小鼠CA1区神经细胞核膜、线粒体及突触结构等受损,而干预组小鼠海马CA1区神经细胞超微结构未见明显异常。结论 SFN可明显改善AD模型小鼠的认知功能,对海马CA1区神经细胞具有保护作用。     

姜黄素对阿尔茨海默病小鼠的治疗作用

目的通过测定阿尔茨海默病(AD)小鼠脑组织中β-淀粉样(Aβ)和磷酸化tau(Ptau)蛋白的阳性表达强度、mRNA水平及脑组织细胞凋亡程度,探讨姜黄素对AD小鼠的治疗机制。方法选取野生C57BL/6和转基因APP/V717雌性小鼠作为研究对象,实验分为对照组(C57BL/6野生雌性小鼠,n=10)、AD模型组(APP/V717转基因雌性小鼠,n=10)和姜黄素治疗组(APP/V717转基因雌性小鼠,n=10),三组均给予正常饮食。对照组和模型组每天灌胃一次生理盐水0.1 ml,姜黄素治疗组每天灌胃一次姜黄素50 mg/kg,共治疗8 w。Morris水迷宫检测各组小鼠记忆能力;苏木素-伊红(HE)染色和Tunnel染色普通光学及荧光显微镜下观察各组小鼠脑组织神经细胞损伤和凋亡程度;免疫组织化学染色和实时荧光定量PCR法检测各组小鼠脑组织中Aβ和Ptau蛋白的阳性表达强度及mRNA水平。结果 Morris水迷宫检测姜黄素治疗组小鼠记忆能力较模型组明显提高(P0.05)。HE染色可见姜黄素治疗组小鼠脑组织神经细胞固缩坏死较模型组明显减轻(P0.05)。Tunnel染色可见姜黄素治疗组小鼠脑组织神经细胞凋亡数量较模型组明显减少(P0.05)。免疫组织化学染色和实时荧光定量PCR可见姜黄素治疗组小鼠脑组织中Aβ和Ptau蛋白的阳性表达强度及mRNA水平均较模型组明显降低(P0.05)。结论姜黄素治疗能够降低AD小鼠脑组织中Aβ和Ptau蛋白的阳性表达强度及mRNA水平,提高AD小鼠学习记忆能力并抑制脑组织细胞凋亡。     

健脑安对血管性痴呆模型大鼠海马胆碱乙酰转移酶和突触素表达的影响

目的观察健脑安对血管性疾呆(VD)大鼠海马胆碱乙酰转移酶(ChAT)和突触素(Syn)表达的影响。方法健脑安口服给药治疗VD大鼠1月后采用免疫组化技术观测大鼠海马ChAT和Syn表达变化,与都可喜(Duxil)对照。结果①各组大鼠海马ChAT和Syn阳性表达面积比较如下,健脑安组(2 980±786.53)/(2 948.0±811.92)μm2和都可喜组(3 116.6±808.25)/(3 086.5±862.48)μm2均明显高于模型组(1 004±464.4)/(1 704±671.74)μm2)P值均<0.01)。②ChAT免疫组化染色:健脑安组和都可喜组大鼠海马ChAT阳性神经细胞排列较规则,胞浆ChAT阳性染色较明显,可见阳性染色神经纤维,较密集。③Syn免疫组化染色:健脑安组和都可喜组大鼠海马神经细胞周围Syn阳性颗粒密集、染色深,可见少量胶质细胞。健脑安组和都可喜组比较未见有明显差异。结论健脑安具有显著增加VD大鼠海马ChAT和Syn表达的作用,这可能是其改善痴呆认知和记忆障碍的作用机制。     

补肾健脾方对AD大鼠AchE、ChAT及海马神经元凋亡的影响

目的研究中药补肾健脾方对阿尔茨海默(AD)大鼠血清及海马组织中乙酰胆碱酯酶(AchE)、胆碱转移酶(ChAT)及神经细胞凋亡的影响。方法雄性SD大鼠随机分为5组:正常组、模型组、假手术组及补肾健脾复方制剂小剂量、大剂量干预组。采用鹅膏蕈氨酸毁损大鼠脑Meynert基底核制备AD动物模型,中药补肾健脾方分别以3.6g/(kg.d)、7.2g/(kg.d)灌胃。30d后以水迷宫测试大鼠学习及记忆能力,对各组大鼠血清及脑海马匀浆中AchE、ChAT的活性进行测定,运用电镜技术及免疫组化检测海马中神经细胞的凋亡及Bax、Bcl-2的表达。结果与模型组比较,补肾健脾复方制剂大、小剂量干预组大鼠的平均逃避潜伏期明显缩短(P0.05),血清及匀浆中AchE的活性下降(P0.05),ChAT活性增高(P0.05),脑皮质的细胞凋亡显著减少(P0.05),脑皮质中Bax阳性神经元数量明显降低(P0.05),Bcl-2阳性神经元的数量显著增加(P0.05)。结论补肾健脾方可在抑制AchE活性的同时增加ChAT的活性,并可通过调节Bax/Bcl-2的表达减少海马组织中神经细胞的凋亡。     

脉心康对载脂蛋白E基因敲除小鼠主动脉核因子κB和基质金属蛋白酶9表达的调控

目的观察脉心康对载脂蛋白E基因敲除小鼠主动脉核因子κB、基质金属蛋白酶9mRNA表达水平的调控作用。方法6周龄载脂蛋白E基因敲除小鼠,随机分为高脂血症组(模型组)、洛伐他汀组及脉心康组,相同遗传背景的同龄正常C57BL6J小鼠为正常对照组。原位杂交观察各组主动脉核因子κB和基质金属蛋白酶9mRNA表达的强度。结果各给药组与模型组比较,核因子κBmRNA、基质金属蛋白酶9mRNA阳性细胞表达率均明显降低(P<0.01)。光镜下发现正常对照组主动脉壁内皮细胞、平滑肌细胞胞质内核因子κBmRNA、基质金属蛋白酶9mRNA阳性表达细胞极少见;模型组主动脉壁内皮细胞、平滑肌细胞胞质内阳性表达的棕褐色颗粒较多见,且棕褐色颗粒染色均较深;脉心康组主动脉壁可见内皮细胞、平滑肌细胞胞质内阳性表达的棕褐色颗粒,但远较模型组少,棕褐色颗粒染色深浅较均匀。结论脉心康可降低载脂蛋白E基因敲除小鼠主动脉核因子κB、基质金属蛋白酶9mRNA表达,发挥抗动脉粥样硬化、稳定斑块的作用。     

脂欣康胶囊对血管平滑肌细胞源性泡沫细胞CD36表达的影响

目的探讨脂欣康胶囊对动脉粥样硬化泡沫化细胞形成的可能调控机制,观察脂欣康胶囊及洛伐他汀干预大鼠血管平滑肌细胞源性泡沫细胞CD36mRNA表达的变化。方法用组织贴块培养法培养血管平滑肌细胞,以氧化型低密度脂蛋白使其泡沫化,并以脂欣康胶囊和洛伐他汀分别干预。采用流式细胞仪和原位杂交技术观察CD36mRNA表达的变化。结果与生理盐水组和空白对照组相比,脂欣康胶囊与洛伐他汀均能降低CD36mRNA的表达(P<0.01),且脂欣康组较洛伐他汀组下降更显著(P<0.05)。结论脂欣康与洛伐他汀均能抑制CD36的表达,并且其作用优于洛伐他汀。其作用机制可能为脂欣康的益气活血、解毒化浊之功使平滑肌细胞内蕴藏的痰浊瘀毒得以疏布排泄于外。这可能是其抑制血管平滑肌细胞增殖和泡沫化细胞形成的机制之一。     

绞股蓝皂甙对阿尔茨海默病小鼠海马胆碱能系统功能的影响

目的 探讨绞股蓝皂甙对D-半乳糖(D-gal)所致阿尔茨海默病(AD)模型小鼠海马胆碱能系统功能的影响.方法 昆明小鼠颈背部皮下注射10％ D-gal,连续6 w造模.同时,各组分别灌胃生理盐水(正常对照组、模型组)、绞股蓝(高、低剂量组).给药结束后进行水迷宫训练,24h后进行学习记忆功能测试和海马胆碱乙酰基转移酶(ChAT)与乙酰胆碱酯酶(AchE)活性测定以及Western印迹检测ChAT表达.结果 与正常对照组相比,D-gal模型组小鼠学习记忆能力,模型组ChAT活性和ChaT表达明显下降(P ＜0.05,P＜0.01);模型组AchE活性明显升高(P＜0.01).给予绞股蓝皂甙可明显改善AD模型小鼠的学习记忆功能(P＜0.05,P＜0.01),增强海马ChAT活性(P＜0.01)和降低AchE活性(P＜0.01),上调ChAT的表达(P＜0.01).结论 绞股蓝皂甙可明显提高模型小鼠的学习记忆能力,改善海马胆碱能系统功能.     

Orai1在载脂蛋白E基因敲除小鼠动脉粥样硬化斑块形成中的表达

目的探讨Orai1在载脂蛋白E基因敲除(Apo E-/-)小鼠动脉粥样硬化斑块形成过程中的表达。方法选取7~8周龄雄性Apo E-/-小鼠及野生型C57BL/6J小鼠,高脂饲喂20、27和33周后,在各个时点处死动物。取主动脉制备连续切片,HE、Masson染色计算机图像分析仪测定斑块面积占管腔面积百分比,及胶原成分占斑块面积百分比;油红O染色分析斑块中脂质含量;免疫组织化学染色测定平滑肌细胞阳性表达Orai1的百分比;Western Blot定量分析Orai1在易损斑块形成过程中的动态表达。结果与同周龄C57BL/6J小鼠相比,Apo E-/-小鼠主动脉Orai1表达增高,且随着其周龄增加,Orai1在Apo E-/-小鼠主动脉的表达动态升高(P0.05)。结论 Orai1参与动脉粥样硬化斑块形成的病理过程,在其形成过程中其表达上调。     

动脉粥样硬化斑块内FIZZ1表达促进平滑肌细胞清道夫受体-A上调

目的探讨ApoE基因敲除鼠动脉粥样硬化斑块内FIZZ1表达情况及其对平滑肌细胞清道夫受体A(SR-A)表达的影响.方法C57BL/6J ApoE基因敲除鼠及C57BL/6J野生型小鼠各9只,分别喂养高脂饲料及普通饲料,24周后处死小鼠,石蜡包埋血管后做连续切片,行HE染色及FIZZ1免疫组化.用氧化型低密度脂蛋白(ox-LDL)以及终浓度分别为3×10-6mmol/L、9×10-6mmol/L、2.7×10-5mmol/L的FIZZ1刺激培养的平滑肌细胞,激光共聚焦显微镜确认SR-A表达后,流式细胞术检测FIZZ1对ox-LDL诱导的平滑肌细胞SR-A表达的影响.结果ApoE基因敲除鼠高脂饲养24周后,主动脉根部明显形成动脉粥样硬化,可见FIZZ1在动脉粥样硬化斑块内明显表达,同龄野生型C57BL/6J鼠正常血管壁内,未见FIZZ1表达,重组FIZZ1能明显促进ox-LDL诱导的平滑肌细胞SR-A表达(与对照组比较,P<0.01).结论C57BL/6J野生型小鼠正常血管不表达FIZZ1,C57BL/6JApoE基因敲除鼠动脉粥样斑块表达FIZZ1,FIZZ1促进ox-LDL诱导的平滑肌细胞SR-A表达,提示FIZZ1可能在ApoE基因敲除鼠动脉粥样硬化进展中起一定的促进作用.     

BCG-malaria co-Infection has paradoxical effects on C57BL/6 and A/J mouse strains.

Bacillus Calmette-Guérin (BCG) infection of the spleen is a potent modifier of splenic function. Prior to malaria infection, we infected two mouse strains of differing susceptibility to Plasmodium chabaudi AS (C57BL/6 and A/J) with this mycobacterium. We then evaluated aspects of spleen cell composition, architecture and cytokine expression, and correlated these with the outcome. BCG preinfection resulted in protection of the A/J mice but paradoxically resulted in mortality of the C57BL/6 mice. The latter developed higher parasitaemias that peaked earlier than the A/J mice rendered resistant by BCG. BCG infection induced remarkable changes to splenic histology examined by H&E staining, but there were no consistent differences between mouse strains. C57BL/6 mice had higher absolute numbers of all immune cell phenotypes than did A/J mice, and higher macrophage and dendritic cell proportions. BCG-induced resistance in A/J mice was associated with an increased CD4+ expression of IFN-gamma whilst induced death in C57BL/6 mice was associated with excessive IFN-gamma expression. A moderate TH1 response in the A/J model may have been responsible for the improved survival, and an excessive TH1 response in the C57BL/6 model may have contributed to their death.     

Chlamydia pneumoniae infection and hyperlipidaemia-induced expression of P50 and c-Fos in the heart of C57BL6J mice

OBJECTIVE: The objective of this study was to investigate infection by Chlamydia pneumoniae (C. pneumoniae) and the combined effects of an atherogenic diet on the expression of AP-1 or the subunit of AP-1 (c-Fos) and NF-kappaB or the subunit of NF-kappaB (P50) in myocardial cells of C57BL/6J mice. METHODS AND RESULTS: Thirty-six 8-week-old female C57BL/6J mice were divided into three groups: A, B and C (twelve mice in each group). Mice in group A were fed an atherogenic diet (consisting of 15% fat and 2.5% cholesterol). Those in group B and C (as blank control) were fed a regular diet. The mice in group B were infected with C. pneumoniae. Fourteen weeks later, the expression of P50 (subunit of NF-kappaB) and c-Fos (subunit of AP-1) in the heart was determined by indirect immunofluorescence in the myocardial cells. Binding activity of NF-kappaB and AP-1 in the heart was determined by electrophoretic mobility shift assay (EMSA). The expression of NF-kappaB and AP-1 in the myocardial cells was upregulated in group A and B, compared with group C (P < 0.05). There was no significant difference between group A and B. CONCLUSION: The inflammatory process was already initiated in the myocardial cells in C57BL/6J mice at the early stage of C. pneumoniae infection and hyperlipidaemia. The expression of NF-kappaB and AP-1 was upregulated in mice infected by C. pneumoniae or fed an atherogenic diet. C. pneumoniae or hyperlipidaemia may involve the pathogenesis and progression of ischaemic cardiomyopathy.     

Gut microbiota,tight junction protein expression,intestinal resistance,bacterial translocation and mortality following cholestasis depend on the genetic background of the host

Failure of the intestinal barrier is a characteristic feature of cholestasis. We have previously observed higher mortality in C57BL/6J compared with A/J mice following common bile duct ligation (CBDL). We hypothesized the alteration in gut barrier function following cholestasis would vary by genetic background. Following one week of CBDL, jejunal TEER was significantly reduced in each ligated mouse compared with their sham counterparts; moreover, jejunal TEER was significantly lower in both sham and ligated C57BL/6J compared with sham and ligated A/J mice, respectively. Bacterial translocation to mesenteric lymph nodes was significantly increased in C57BL/6J mice vs. A/J mice. Four of 15 C57BL/6J mice were bacteremic; whereas, none of the 17 A/J mice were. Jejunal IFN-γ mRNA expression was significantly elevated in C57BL/6J compared with A/J mice. Western blot analysis demonstrated a significant decrease in occludin protein expression in C57BL/6J compared with A/J mice following both sham operation and CBDL. Only C57BL/6J mice demonstrated a marked decrease in ZO-1 protein expression following CBDL compared with shams. Pyrosequencing of the 16S rRNA gene in fecal samples showed a dysbiosis only in C57BL/6J mice following CBDL when compared with shams. This study provides evidence of strain differences in gut microbiota, tight junction protein expression, intestinal resistance and bacterial translocation which supports the notion of a genetic predisposition to exaggerated injury following cholestasis.     

The relationship between age-related hearing loss and synaptic changes in the hippocampus of C57BL/6J mice

To explore the relationship between age-related hearing loss (presbycusis) and synaptic degeneration in the hippocampal CA3 region of C57BL/6J mice, we investigated both cognitive performance and synaptic changes within the hippocampus of C57BL/6J mice from three age groups of 6-8, 24-26, and 42-44 weeks; CBA/CaJ mice served as controls. The auditory brainstem response was used as a measure of hearing threshold, and cognitive behavior was evaluated using the Morris water maze. The ultrastructure of synapses was observed with transmission electron microscopy, and the quantity and distribution of the synaptic markers synaptophysin and PSD-95 were observed with immunohistochemistry. The hearing threshold of C57BL/6J mice was significantly higher at 24-26 weeks than at 6-8 weeks, and hearing loss was profound at 42-44 weeks. This was accompanied by progressive degeneration of synapses within the auditory cortex. In contrast, the hearing threshold of CBA/CaJ mice was relatively unchanged at 24-26 weeks of age, and these mice developed only mild hearing loss at 42-44 weeks of age. Interestingly, C57BL/6J, but not CBA/CaJ mice clearly exhibited both decreased performance in the Morris water maze and degeneration of synapses within the hippocampus. We therefore conclude that age-related hearing loss is accompanied by the degeneration of synapses in the hippocampal CA3 region of C57BL/6J mice.     

Comparison of basal neuropeptide Y and corticotropin releasing factor levels between the high ethanol drinking C57BL/6J and low ethanol drinking DBA/2J inbred mouse strains

BACKGROUND: Recent genetic and pharmacological evidence indicates that low neuropeptide Y (NPY) levels in brain regions involved with neurobiological responses to ethanol promote increased ethanol consumption. Because of their opposing actions, it has been suggested that NPY and corticotropin releasing factor (CRF) exert a reciprocal regulation on drug self-administration. It has been widely reported that inbred C57BL/6 mice consume significantly higher amounts of ethanol than do DBA/2 mice. Therefore, we used immunohistochemical techniques to determine if basal NPY and/or CRF levels differed in predicted directions between C57BL/6J and DBA/2J mice. METHODS: Ethanol-naive C57BL/6J and DBA/2J mice were deeply anesthetized with sodium pentobarbital (100 mg/kg) and perfused transcardially with 0.1 mM of phosphate-buffered saline followed by 4% paraformaldehyde in buffered saline. Brains were collected and postfixed for 4 hr at 4 degrees C and then were cut into 35-microm sections. Tissues containing the nucleus accumbens (NAc), hypothalamus, and amygdala were processed for NPY or CRF immunoreactivity using immunofluorescent or DAB techniques. Immunoreactivity was quantified from digital images using Image J software. RESULTS: The C57BL/6J mice showed reduced NPY expression in the NAc shell, the basolateral amygdala, and the central nucleus of the amygdala when compared with DBA/2J mice. However, these strains did not differ in CRF expression in any of the brain regions analyzed. CONCLUSIONS: These data suggest that low NPY levels in the amygdala and/or the shell of the NAc, which are not compensated for by similar changes in CRF levels, may contribute to the high ethanol consumption characteristic of C57BL/6J mice.     

Strain-dependent stimulation of growth in leptin-treated obese db/db mice

Leptin increases the proliferation of various cell types in vitro, and we reported that background strain influences the metabolic responses to leptin in db/db mice, which express short-form, but not long-form, leptin receptors. Here, we examined the effects of leptin on growth of young C57BL/Ks, C57BL/6J, and C57BL/3J db/db mice. Intraperitoneal infusions of 20 micro g leptin/d for 26 d increased the food intake of C57BL/6J mice by 15% (P < 0.01), but had no effect in C57BL/Ks db/db mice. Leptin-infused C57BL/6J db/db mice gained more weight ( approximately 20%; P < 0.04) than PBS-infused controls. The increased weight was sustained after leptin infusion ended. Leptin had no effect on weight gain or food intake of C57BL/3J db/db mice, which only express the soluble leptin receptor. A single leptin injection increased MAPK phosphorylation in liver by 40% (P < 0.001) and that in muscle tissues by 20% (P < 0.001) in C57BL/6J mice, but did not change phosphorylation in C57BL/3J db/db mice. These results suggest that leptin increases the weight gain of C57BL/6J db/db mice by activating the MAPK pathway through a mechanism that is dependent on short-form leptin receptors. This response may be masked by activation of the long-form receptor in wild-type animals that lose body fat during leptin treatment.     

同型半胱氨酸对Kkay小鼠糖尿病肾病作用机制的探讨

目的 探讨基质金属蛋白酶-9(MMP-9)在同型半胱氨酸(Hcy)加重糖尿病肾病(DN)过程中的可能作用。方法 22～24周龄Kkay糖尿病鼠16只随机分两组:糖尿病组(KA)和高蛋氨酸组(KB),每组8只;C57BL/6小鼠9只为对照组(C57),以相应饲料喂养4个月后取材。测定血糖和血Hcy水平,以PAS染色观察各组肾组织肾小球病理改变,比较肾小球硬化指数(GI)。对肾脏MMP-9表达进行免疫组化染色和半定量图像分析,并以逆转录PCR检测。肾脏MMP-9 mRNA的表达水平。结果 与C57对照组相比,Kkay两组均有不同程度糖尿病肾病病变,其中KB组病变更重,其GI值(283.33)高于KA组(240.00),P<0.05。免疫组化显示KB组肾小球MMP-9阳性着色面积(15.90％)高于KA组(11.14％),P<0.05,MMP-9 mRNA表达水平KB组高于KA组。结论 高Hcy血症具有加重Kkay小鼠糖尿病肾病程度的作用,此作用可能与上调MMP-9的表达水平有关。     

Effects of sphingolipid synthesis inhibition on cholesterol gallstone formation in C57BL/6J mice

Background: Sphingolipids play a very important role in cell membrane formation, signal transduction and plasma lipoprotein metabolism. The first rate‐limiting step in the sphingolipid biosynthetic pathway is catalyzed by serine palmitoyltransferase (SPT), and myriocin is a potent and specific inhibitor of SPT. We investigated the impact of SPT inhibition on cholesterol gallstone formation in C57BL/6J mice. Methods: Three groups of eight‐week‐old C57BL/6J mice were utilized. Each group consisted of 20 mice; group A, B, and C were fed normal chow, lithogenic diet with phosphate buffered saline, and lithogenic diet with myriocin (0.3 mg/kg), respectively, for 6 weeks. The ceramide levels in both serum and bile were assessed by high performance liquid chromatography analysis. Protein expression of ERK, JNK and p38 in the extracted gallbladder were determined by Western‐blot analysis. Results: Myriocin treatment caused a significant decrease in the rate of cholesterol gallstone formation. The lithogenic diet mice (group B) showed the highest ceramide activities in both the serum and bile among all the tested groups and there was significant suppression of the ceramide levels in both the serum and bile of the myriocin‐treated mice (group C, p < 0.05). Phosphorylation of p38 in the gallbladder was increased in the lithogenic‐diet mice and the expression of phosphorylated p38 was significantly suppressed in the myriocin treated mice. Conclusions: SPT inhibition by myriocin suppressed gallstone formation and the levels of ceramide in both the serum and bile. p38 in the cellular signaling pathways might be associated with cholesterol gallstone formation.     

AMPK基因在C57BL／6J小鼠糖脂代谢中的作用

目的研究腺苷酸活化蛋白激酶（AMPK）基因在C57BL／6J小鼠糖脂代谢中的作用。方法分别取5周龄AMPK基因敲除（AMPK-KO）小鼠和C57BL／6J对照小鼠各24只,分为正常饲料（ND）喂养和高脂高糖饲料（HFD）喂养两组。喂养12周,每两周测定小鼠禁食4h血糖（FBG）,实验结束前行口服糖耐量实验（OGTT）,解剖取样,检测血生化指标、脂酶活性及相关蛋白的表达。结果AMPK-KO小鼠血糖、TC、LDL-C、HbA1c、6-磷酸葡萄糖脱氢酶（G6PD）活性、糖原合成酶激酶（GSK）活性、肝脏PPAR7蛋白表达量明显高于对照小鼠（P〈0．05）;其胰岛素含量、肝糖原含量、肌糖原含量、肝脂酶（HL）活性、脂蛋白酯酶（LPL）活性、总脂酶活性、葡萄糖激酶（GK）活性、肝组织P-AMPK蛋白、葡萄糖转运蛋白4（GluT-4）蛋白的表达量低于对照组（P〈0．05）。结论AMPK基因通过调节C57BL／6J小鼠糖脂代谢,在T2DM的发病中起重要作用。