中国健康人群与精神分裂症患者CYP2D6(C100T)遗传多态性的相关研究

目的探讨中国健康人群与精神分裂症患者细胞色素P4502D6（CYP2D6）遗传多态性的相关性。方法应用PCR与DNA测序相结合的方法对88名精神分裂症患者（男40例，女48例；平均年龄40．38±13．45岁）与93名健康志愿者（男40例，女53例；平均年龄43．60±12．05岁）进行了CYP2D6的基因多态性分析，根据CYP2D6（C100T）将精神分裂症患者和健康志愿者基因型分为三组（C／C，C／T，T／T）。结果在CYP2D6（C100T）的基因型和等位基因型检测中，精神分裂症患者和健康志愿者组间的基因型和等住基因没有显著性差异（x^2=0．202，P〉0．05；x^2=0．066，P〉0．05）。结论CYP2D6（C100T）可能不是中国精神分裂症患者的一个易感因素。     

曲尼司特对犬颈动脉球囊损伤模型的抗狭窄作用

目的：通过球囊损伤犬颈动脉模型观察曲尼司特对颈动脉损伤后再狭窄的作用。方法：9只犬被随机分为对照组（n=5）及曲尼司特干预组（50mg·kg^-1，n=4），颈总动脉损伤前2周及术后4周进行分组干预。通过测定血浆AngⅠ及AngⅡ水平、糜酶（chymase）mRNA表达水平、颈动脉细胞增殖核抗原（PCNA）阳性率及颈动脉各层厚度观察曲尼司特对犬颈动脉损伤后狭窄的作用。结果：两组血浆AngⅠ、AngⅡ水平及颈动脉外／中膜厚度无明显改变（P〉0．05）；但曲尼司特组较对照组的糜酶mRNA表达（A值分别为0．425±0．114比0．708±0．083）、颈动脉各层PCNA阳性率（内膜：0．45±0．05比0．57±0．12，中膜：0．54±0．05比0．61±0．02，外膜：0．25±0．10比0．36±0．08）及颈动脉内／中膜厚度（0．518±0．044比0．576±0．028）均明显降低，P〈0．05。结论：曲尼司特通过糜酶途径对犬颈动脉球囊损伤后的再狭窄具有抑制作用。     

牛磺酸对肝纤维化大鼠肝微粒体细胞色素P450和b5的影响

目的研究牛磺酸对实验性肝纤雏化大鼠肝微粒体细胞色素P450（CytP450）、Cytb5水平的影响。方法建立四氯化碳（CCL4）肝纤维化模型,以牛磺酸灌胃治疗,并设秋水仙碱组和空白对照组,用化学方法检测肝微粒体CytP450和Cytb5含量。结果CCk模型组CytP450为（0．211±0．027）nmol／mg protein,Cytb5为（0．256±0．069）nmol／mg protein,与空白对照组比较差异有统计学意义（P〈0．01）;牛磺酸组CytP450为（0．691±0．106）nmol／L,Cytb5为（0．761±0．131）nmol／L,与空白对照组和秋水仙碱组比较差异无统计学意义（P〉0．05）。结论牛磺酸在抗肝纤维化方面与秋水仙碱具有类似的功效,而且至少在某一方面是恢复肝CytP450、Cytb5酶活性而产生作用。     

运动对大鼠骨矿盐含量的影响

目的：分析运动对正常成年大鼠和切除双侧卵巢后的大鼠骨矿盐代谢的影响。 方法：本实验于2002—10／2003—05在广东医学院生理学教研室完成。普通级4月龄SD雌性大鼠30只。随机分成5组：正常对照组；正常大鼠＋运动组；假去卵巢组；去卵巢组；去卵巢＋运动组。然后重复，每组6只。正常大鼠＋运动组和去卵巢＋运动组大鼠于术后第7天开始进行运动训练．5d／周．45min／d．16m／min．跑道倾角0°．持续10周。第10周末．麻醉状态下动脉放血处死各组大鼠，观察骨干重、骨干重／体质量、骨灰重、骨灰重／体质量、骨灰重／骨干重（％）代谢变化。 结果：30只大鼠均进入结果分析。大鼠骨干重、骨干重／体质量、骨灰重、骨灰重／体质量、骨灰重／骨干重（％）各指标代谢变化：正常大鼠＋运动组各指标均显著高于正常对照组[（645±48），（567±32）mg；（1．97±0．06），（1．73±0．10）g／kg；（440±30），（374±91）mg；（135±0.04），（1．14±0.06）g／kg；（68．2±0．7）％，（65．9±0．9）％，t=3．46-6．92，P〈0.01]；去卵巢组各指标均明显低于假去卵巢组[（504±24），（569±40）mg；（1．55±0．61），（1．83±0．19）g／kg；（293±14），（381±23）mg；（0．90±0．04），（1．21±0．14）g／kg；（58．6±0．8）％，（66．3±1．5）％，t=3．64-15．58，P〈0．01]；去卵巢＋运动组各指标均较去卵巢组明显增加（627±70），（504±24）mg；（1．76±0．11），（155±0．61）g／kg；（409±43），（293±14）mg；（1.15±0．08），（0．90±0．04）g／kg；（65．2±1．2）%，（58．6±0．8）％。t=3．90-11．21。P〈0．01）。 结论：中等强度运动是增加成年大鼠骨矿盐含量和预防去卵巢大鼠骨矿盐丢失的有效措施。     

保肝益胃合剂对四氯化碳致大鼠急性肝损伤的保护作用

目的 观察保肝益胃合剂对四氯化碳（CCl4）所致大鼠急性肝损伤的保护作用。方法 腹腔注射CCl42ml／kg建立大鼠急性肝损伤模型。分别用保肝益胃合剂（30g·kg^-1·d^-1）、多烯磷脂酰胆碱胶囊（易善复，180mg·kg^-1·d^-1）、甘草酸二铵胶囊（甘利欣，30mg·kg^-1·d^-1）灌胃，联合治疗组则用保肝益胃合剂（30g·kg^-1·d^-1）＋易善复（180mg·kg^-1·d^-1）灌胃。检测各组大鼠血清中丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）活性，同时观察肝脏组织病理学变化以及肝细胞坏死评分和大鼠死亡率。结果 保肝益胃合剂组ALT、AST活性和肝细胞坏死评分[（1．168±1．066）kU／L、（1．845±2．212）kU／L、（0．56±0．53）分]均显著低于模型组[（4．982±3．502）kU／L、（7．030±3．616）kU／L、（1．38±0．92）分，P均〈0．013。正常对照组大鼠无死亡；保肝益胃合剂组和保肝益胃合剂＋易善复组大鼠死亡率（分别为37．5％、25．0％）均较模型组（60．0％）明显降低，以联用组为最低（P〈0．05）。结论 保肝益胃合剂对CCl4所致大鼠急性肝损伤有明显的保护作用。     

高血压与冠心病患者血浆中TFPI和D-D的变化及临床意义

目的探讨50例高血压与50例冠心病患者血浆组织因子途径抑制物（TFPI）、D-二聚体（D-D）的变化及临床意义。方法TFPI抗原（TFPI—Ag）采用双夹心ELISA抗原测定法，D-D用免疫比浊法检测。结果50例高血压组的TFPI抗原含量（13．56±4．31）ng／mL，50例冠心病组TFPI抗原含量（15．32±3．25）ng／mL，均比健康对照组（10．00±4．80）ng／mL高，两者比较差异均有统计学意义（P〈0．01，P〈0．01）。50例高血压组的D-D为（1．39±0．25）mg／L，50例冠心病组的D-D为（1．78±0．16）mg／L，均比健康对照组（0．25±0．13）mg／L高，两者比较差异均有统计学意义（P〈0．01，P〈0．01）。结论检测高血压和冠心病患者血浆TFPI、D-D含量，对早期诊断和防止血栓形成具有重要意义。     

慢性疲劳综合征患者治疗前后血清维生素B12、叶酸水平的变化

目的了解慢性疲劳综合征与血清维生素B12和叶酸的关系。方法分别测定58例慢性疲劳综合征患者按照中医辨证分型服用汤荆治疗前、后的血清维生素B12和叶酸含量,并与健康对照组进行比较。结果患者组于服用汤荆治疗前,血清叶酸含量（8．54±0．74ng／ml）与健康对照组（9．12±0．83ng／ml）相比,差异无统计学显著性意义（t=1．126,P〉0．05）;而血清维生素B12含量（307±25．78pg／ml）明显低于健康对照组（503±29．19pg／ml）,差异有统计学显著性意义t=1．874,P〈0．05）;患者组服用汤剂治疗后,其血清叶酸含量（8．85±0．77ng／ml）与健康对照组（9．12±0．83ng／ml）相比,差异无统计学意义0=1．187,P〉0．05）;血清维生素B12含量（451±27．99pg／ml）与健康对照组（503±29．19pg／ml）相比,差异也无统计学意义（t=1．536,P〉0．05）。结论血清维生素B12缺乏很可能是慢性疲劳综合征的原因之一。     

山莨菪碱对兔心室肌细胞离子通道电流的影响

目的研究山莨菪碱对兔正常离体心室彤睫田胞离子通道电流的影响,探讨其抗心律失常的细胞学离子机制。方法以酶解的方法分离兔心室肌外膜单个心室肌细胞,采用全细胞膜片钳技术,研究不同浓度山莨菪碱对兔正常心室肌细胞跨膜钠离子通道电流（INa）、L-钙通道电流（ICa-L）及瞬间外向钾通道电流（Ito）的影响。结果山莨菪碱浓度为10nmol／L时,对INa无明显影响（P〉0．05）。山莨菪碱浓度为100nmol／L时,INa电流密度减少到（-33．25±4．46）pA／pF,1000nmol／L时INa电流密度减少到（-29．32±3．55）pA／pF,抑制率分别为22．3％和31．5％,与基础值比较,差异均有统计学意义（P〈0．01）。山莨菪碱浓度为10nmol／L时,对ICa-L无明显影响（P〉0．05）。山莨菪碱浓度为100nmol／L时,ICa-L．电流密度减少到（-2．15±1．02）pA／pF,1000nmol／L时ICa-L电流密度减少到（-1．82±0．86）pA／pF,抑制率分别为31．3％和41．8％,与基础值比较,差异均有统计学意义（P〈0．01）。山莨菪碱浓度为10nmol／L时,Ito电流密度由（17．41±3．13）pA／pF减少到（16．13±2．93）pA／pF,100nmol／L时减少到（15．11±2．88）pA／pF,1000nmol／L时减少到（14．96±2．82）pA／pF,抑制率分别为7．3％、13．2％和14．1％,均无统计学差异（P〉0．05）。结论山莨若碱对离体正常单个心室肌细胞INa和ICa-L具有剂量依赖性抑制作用。     

厄贝沙坦对原发性高血压左室肥厚及血浆脑钠素水平的影响

【目的】探讨厄贝沙坦对原发性高血压（EH）左室肥厚的逆转作用及对血浆脑钠素（BNP）水平的影响。【方法】80例EH分为左室肥厚组（LVH组，46例）及无左室肥厚组（无LVH组，34例），并选30例健康体检者做对照，LVH组及无LVH组每天给厄贝沙坦75～150mg治疗6个月。治疗前后用彩色超声多普勒检测左室相关指标左室质量指数（LVMI），并用酶联免疫标记法（ELISA）测定血浆BNP浓度。【结果】治疗前，三组相比，血浆BNP水平存在明显差异[（258±72）μg／Lvs（92±42）μg／Lvs（37±15）μg／L，P〈0．05]，而LVH组较无LVH组明显升高[（258±72）μg／Lvs（92±42）μg／L，P〈0．05]；治疗后LVH组LVMI较前明显减小[（135．1±12．1）g／m^2 vs（162．4±11．5）g／m^2，P〈0．05]而无LVH组的改变无统计学意义。LVH组和无LVH组治疗后其血浆BNP水平均较治疗前明显降低[（180±42）μgg／Lvs（258±72）μg／L，P〈0．05；（50±13）μg／Lvs（92_±42）μg／L，P〈0．05]；直线相关分析表明，LVH组的血浆BNP水平与LVMI正相关（r=0．645，P〈0．05），而无LVH组血浆BNP水平与LVMI无明显相关（r=0．352，P〉0．05）。【结论】厄贝沙坦能够有效逆转EH的左室重构，并预防EH可能发生的左室重构，血浆BNP是预测EH发生左室重构的良好指标。     

慢性舒张性心力衰竭合并睡眠呼吸紊乱的观察

目的观察慢性舒张性心力衰竭患者睡眠呼吸紊乱（SDB）发生情况。方法对舒张性心力衰竭患者（现有或既往曾有充血性心力衰竭症状、超声心动网射血分数≥45％且E／A〈1）应用便携式睡眠监测仪Embletta进行睡眠监测，根据呼吸紊乱指数（AHI）将患者分为SDB组（AHI〉10次／h）和非SDB组（AHI≤10次／h），观察两组睡眠期间AHI与血氧饱和度（SO2）（平均SO2、最低SO2和SO2〈90％）和心率（最低心率、最高心率和最大心率变化）的关系。结果共观察36例患者，其巾15例（41．7％）表现出AHI〉10次／h而分为SDB组，其余21例为非SDB组。两组AHI分别为（24．5±15．0）次／h和（4．6±2．7）次／h，睡眠巾最低SO2分别为（78．9±8．7）％和（86．7±3．4）％（P〈0．05）。AHI与SO2〈90％占总记录时间百分比、最低SO2相关（r=0．615和r=-0．626，P〈0．01）。SDB组和非SDB组发生严重心动过缓（心室率≤40次／min）分别为80．0％（12／15）和28．6％（6／21）（P〈0．05）。两组最低心率分别为（36．8±7．0）次／min和（43．7±5．6）次／min，并与AHI、SO2〈90％时间呈负相关（r=-0．489和r=-0．515），与最低SO，呈正相关（r=0．559）（P均〈0．05）。两组最大心率变化分别为（51．8±19．5）次／min和（40．7±9．7）次／min，并与AHI、SO2〈90％的时间呈正相关（r=0．537和r=0．319），与最低SO2、平均SO2呈负相关（r=-0．428和r=-0．344）（P均〈0．05）。结论慢性舒张性心力衰竭合并SDB的患病率很高且伴发严重夜间低氧血症，并可导致患者夜间出现严重心动过缓。     

山奈酚对大鼠胎盘CYP_(450)酶、GSH-PX活性及母鼠血脂的影响

目的研究山奈酚(KA)对SD大鼠胎盘绒毛组织细胞色素P450(cytochrome P450,CYP450)酶、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-PX)活性及母鼠外周血血脂水平的影响。方法选择性成熟SD大鼠120只(雌鼠80只,雄鼠40只),随机分为4组,每组30只(雌鼠20只,雄鼠10只),雌雄分开饲养,KA低、中、高浓度组雌鼠分别予50、100、200 mg/(kg·d)KA灌胃,空白对照组雌鼠予相同体积0.9%氯化钠注射液灌胃,15 d后雌雄鼠同笼,将受孕鼠同法继续灌胃14 d后处死,取胎盘组织测定CYP450酶、GSH-PX活性并检测母鼠外周血血脂水平。结果 KA低、中、高浓度组CYP450酶活性明显低于空白对照组,且随着KA浓度的增加活性逐渐降低;GSH-PX活性明显高于空白对照组,且随着KA浓度的增加活性逐渐升高,差异均有统计学意义(P0.05)。KA低、中、高浓度组总胆固醇、甘油三酯、低密度脂蛋白胆固醇(LDL-C)水平较空白对照组低,且随KA浓度的增加水平逐渐降低,而高密度脂蛋白胆固醇(HDL-C)水平较空白对照组高,且随KA浓度的增加水平逐渐升高,差异均有统计学意义(P0.05)。CYP450酶活性与GSH-PX活性呈负相关(r=-0.534,P=0.037);血清LDL-C与HDL-C水平亦呈负相关(r=-0.551,P=0.032)。结论 KA能降低胎盘组织中CYP450酶活性并升高GSH-PX活性,并可降低母鼠血脂水平。     

电针联合依达拉奉对糖尿病周围神经病变大鼠坐骨神经的保护作用

目的 研究电针联合依达拉奉对糖尿病周围神经病变(DPN)大鼠坐骨神经的保护作用.方法 SD大鼠100只,10只作为正常组,其余90只采用链脲佐菌素(STZ)1次性腹腔注射诱导建立DPN模型,之后随机分为对照组、电针组和针药联合组,电针组取大鼠足三里、肾俞穴进行电针治疗,针药联合组同时给予依达拉奉(3 mg·kg-1·d-1)腹腔注射共4周.观察坐骨神经运动神经传导速度(MCV)、感觉神经传导速度(SCV)形态和坐骨神经中一氧化氮(NO)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性.结果 与正常组比较,时照组大鼠MCV、SCV明显减慢(30.88±3.64)m/s,(28.65±9.44) m/s;(48.39±1.43)m/s,(47.44±8.68)m/s,形态学明显异常,NO、MDA含量明显增多(5.56±0.21)(μ)mol/L,(7.97±0.51)nmol/mg prot;(1.16±0.17)(μ)mol/L,(2.23±0.48)nmol/mg prot,SOD活性显著降低(10.62±1.53) U/mg prot,(20.48±1.55)U/mg prot(P＜0.01),电针组与对照组比较,大鼠MCV、SCV明显加快(36.43±2.28) m/s,(34.43±5.38)m/s(P＜0.01),形态学明显改善,但NO、MDA含量与SOD活性无显著变化(P＞0.05),针药联合组与电针组比较,大鼠MCV、SCV加快更明显(43.67±2.33) m/s,(41.47±5.32) m/s( P＜0.01),形态学有更明显改善,NO、MDA含量较对照组及电针组均明显减少(2.23±0.12)(μ)mol/L,(4.12±0.42)nmol/ mg prot,SOD活性则显著增高(16.69±1.76)U/mg prot(P＜0.01).结论 电针联合依达拉奉应用对DPN大鼠坐骨神经损伤有更明显的保护作用.     

Cytochrome P450 metabolites of arachidonic acid are elevated in stroke patients compared with healthy controls

CYP450AAM [arachidonic acid metabolites of the CYP450 (cytochrome P450) enzyme system] have a range of biological functions. CYP450AAM are involved in the pathogenesis of hypertension, renal function and vascular function, yet their role in stroke has not been clarified. We aimed at determining the levels of circulating CYP450 metabolites in patients with acute ischaemic stroke (<96?h) compared with healthy age- and gender-matched controls. This was a retrospective case-controlled study of 44 acute ischaemic stroke patients and 44 matched controls. A subset of acute ischaemic stroke patients was available for follow-up. Acute ischaemic stroke patients had elevated plasma CYP450AAM, including 20-HETE (20-hydroxyeicosatetraenoic acid) (1921±170 compared with 1108±170?pmol/l, P<0.001), EETs (epoxyeicosatrienoic acids) (77.88±3.34 compared with 35.35±3.34 nmol/l, P<0.0001) and DiHETEs (dihydroxyeicosatetraenoic acids) (92.87±4.61 compared with 68.17±4.61 nmol/l, P<0.0001), as well as increased plasma F2-isoprostane levels (3754±538 compared with 1947±538?pmol/l, P<0.02), the latter a marker of oxidative stress, compared with controls. In a subset analysis of the stroke patients, plasma 20-HETE, EETs and F2-isoprostanes were attenuated 30?days after the stroke. Baseline 20-HETE levels were also associated with lesion size and functional indices within the stroke patients. The present study highlights the elevation in CYP450AAM and oxidative stress in acute ischaemic stroke patients. Further investigation of the effect this has on long-term clinical outcome or whether this can be modified by treatment is warranted.     

Chronic intragastric infusion of ethanol-containing diets induces CYP3A9 while decreasing CYP3A2 in male rats

The CYP3A subfamily is the most abundant of the human hepatic cytochrome P450 enzymes. They mediate the biotransformation of many drugs, including a number of psychotropic, cardiac, analgesic, hormonal, immunosuppressant, antineoplastic, and antihistaminic agents. We studied diet/ethanol interactions using total enteral nutrition in adult male Sprague-Dawley rats with diets containing 16% protein, ethanol (13 g/kg), corn oil (fat; 25-45%), and carbohydrate (CHO; 1-21%). Using this model, chronic ethanol feeding decreased CYP3A activity (testosterone 6 beta-hydroxylation) and apoprotein levels (Western blot) (P <.05) and these effects were independent of the dietary CHO/fat ratio. The CYP3A2 mRNA levels decreased (P <.05) in the rats fed ethanol-containing diets by 73 to 83% compared with rats fed control diets, regardless of the CHO/fat ratio. In contrast, ethanol induced CYP3A9 mRNA levels (P <.05) and this effect was greater (P <.05) in the high-CHO/low-fat group (11.3-fold) than in the low-CHO/high-fat group (2.6-fold). Purified recombinant rat P450 3A9 had a chlorzoxazone 6-hydroxylase activity with a turnover number 1.3 nmol/min/nmol of P450. These results indicate that 1) ethanol differentially affects the expression of CYP3A gene family and this regulation appears to be modulated by dietary CHO/fat ratio; 2) the decrease in testosterone 6 beta-hydroxylase activity and CYP3A apoprotein levels are most likely due to the ethanol-induced decrease in CYP3A2 mRNA levels; and 3) CYP3A9 is induced by ethanol and is a low-affinity, high-K(m) chlorzoxazone hydroxylase.     

In vitro metabolism of quinidine: the (3S)-3-hydroxylation of quinidine is a specific marker reaction for cytochrome P-4503A4 activity in human liver microsomes

The aim of this study was to evaluate the (3S)-3-hydroxylation and the N-oxidation of quinidine as biomarkers for cytochrome P-450 (CYP)3A4 activity in human liver microsome preparations. An HPLC method was developed to assay the metabolites (3S)-3-hydroxyquinidine (3-OH-Q) and quinidine N-oxide (Q-N-OX) formed during incubation with microsomes from human liver and from Saccharomyces cerevisiae strains expressing 10 human CYPs. 3-OH-Q formation complied with Michaelis-Menten kinetics (mean values of Vmax and Km: 74.4 nmol/mg/h and 74.2 microM, respectively). Q-N-OX formation followed two-site kinetics with mean values of Vmax, Km and Vmax/Km for the low affinity isozyme of 15.9 nmol/mg/h, 76.1 microM and 0.03 ml/mg/h, respectively. 3-OH-Q and Q-N-OX formations were potently inhibited by ketoconazole, itraconazole, and triacetyloleandomycin. Isozyme specific inhibitors of CYP1A2, -2C9, -2C19, -2D6, and -2E1 did not inhibit 3-OH-Q or Q-N-OX formation, with Ki values comparable with previously reported values. Statistically significant correlations were observed between CYP3A4 content and formations of 3-OH-Q and Q-N-OX in 12 human liver microsome preparations. Studies with yeast-expressed isozymes revealed that only CYP3A4 actively catalyzed the (3S)-3-hydroxylation. CYP3A4 was the most active enzyme in Q-N-OX formation, but CYP2C9 and 2E1 also catalyzed minor proportions of the N-oxidation. In conclusion, our studies demonstrate that only CYP3A4 is actively involved in the formation of 3-OH-Q. Hence, the (3S)-3-hydroxylation of quinidine is a specific probe for CYP3A4 activity in human liver microsome preparations, whereas the N-oxidation of quinidine is a somewhat less specific marker reaction for CYP3A4 activity, because the presence of a low affinity enzyme is demonstrated by different approaches.     

儿童血清胱抑素C参考区间的建立

目的 建立本实验室儿童血清胱抑素C的参考区间.方法 通过比较儿童与成人的血清胱抑素C水平,比较其参考区间的差异,对儿童血清胱抑素C进行对数转换后进行正态性统计分析,从而建立其参考区间.结果 血清胱抑素C经对数转换后呈近正态分布,1～16岁儿童血清胱抑素C水平:男性(0.86±0.225)mg/L、女性(0.81±0.218)mg/L与青年组的血清胱抑素C水平:男性(0.87±0.192)mg/L、女性(0.83±0.202)mg/L之间的差异无统计学意义(P＞0.5),但与中年组的血清胱抑素C水平:男性(0.93±0.200)mg/L、女性(0.85±0.199)mg/L和老年组的血清胱抑素C水平;男性(1.07±0.216)mg/L、女性(1.00±0.219)mg/L的差异有统计学意义(P＜0.01),在儿童组中,男、女组之间差异有统计学意义(P＜0.01).结论本实验儿童血清胱抑素C水平的参考区间:0.42～1.30 mg/L(男)、0.38～1.24 mg/L(女).     

Mitigating role of baicalein on lysosomal enzymes and xenobiotic metabolizing enzyme status during lung carcinogenesis of Swiss albino mice induced by benzo(a)pyrene

The lungs mainly serve as a primary site for xenobiotic metabolism and constitute an important defense mechanism against inhalation of carcinogens. Our current study aimed to evaluate the chemotherapeutic efficacy of baicalein (BE) in Swiss albino mice exposed to tobacco‐specific carcinogen benzo(a)pyrene [B(a)P] for its ability to mitigate pulmonary carcinogenesis. Here, we report that altered activities/levels of lysosomal enzymes (cathepsin‐D, cathepsin‐B, acid phosphatase, β‐D‐galactosidase, β‐D‐glucuronidase, and β‐D‐N‐acetyl glucosaminidase), phase I biotransformation enzymes (cytochrome P450, cytochrome b5, NADPH‐cytochrome P450 reductase, and NADH‐cytochrome b5 reductase), and phase II enzymes (glutathione S‐transferase, UDP‐glucuronyl transferase, and DT‐diaphorase) were observed in the B(a)P‐induced mice. Treatment with BE significantly restored back the activities/levels of lysosomal enzymes, phase I and phase II biotransformation enzymes. Moreover, assessment of lysosomal abnormalities by transmission electron microscopic examination revealed that BE treatment effectively counteract B(a)P‐induced oxidative damages. Protein expression levels studied by immunohistochemistry, immunofluorescence, and immunoblot analysis of CYP1A1 revealed that BE treatment effectively negate B(a)P‐induced upregulated expression of CYP1A1. Further analysis of scanning electron microscopic studies in lung was carried out to substantiate the anticarcinogenic effect of BE. The overall data suggest that BE treatment significantly inhibits lysosomal and microsomal dysfunction, thus revealing its potent anticarcinogenic effect.     

番茄红素对慢性苯染毒小鼠抗氧化酶的影响

背景苯中毒主要对造血系统和神经系统造成损伤,导致DNA损伤,DNA加合物形成等.番茄红素是一种重要的类胡罗卜素,具有多种生物学作用,如抗氧化、抗肿瘤、诱导细胞间隙连接通讯等. 目的探讨番茄红素对慢性苯染毒所造成的氧化损伤的拮抗作用.设计随机对照的实验研究.地点和材料哈尔滨医科大学公共卫生学院动物室.选用纯种雄性健康昆明鼠30只,由哈尔滨医科大学附属第二医院动物中心提供.干预措施分为对照组、苯染毒组和番茄红素组,每组10只.对照组不染毒,苯染毒组和番茄红素组静式吸入苯蒸气,番茄红素组给予番茄红素,60 d后处死,取肝、脾、脑组织.主要观察指标测定肝、脾和脑中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力及丙二醛含量.结果苯染毒能够明显,降低组织匀浆中SOD活性[肝、脾、脑分别为(12.57±1.94),(5.57±0.81),(8.28 ±2.25)μkat/g],GSH-Px活力[肝、脾、脑分别为(0.38±0.05),(0.52 ±0.05),(0.10±0.01)mkat/g],升高丙二醛含量[肝、脾、脑分别为(2.85 ±0.38),(3.58 ±0.53),(3.10±0.89)μmol/g].给予番茄红素后可使小鼠组织匀浆的SOD活性(μkat/g)升高(肝、脾、脑分别为16.08±2.55,6.43±1.28,9.03±1.52),GSH-Px活力(mkat/g)上升(肝、脾、脑分别为0.53 ±0.08,0.62 ±0.07,0.12 ±0.01),丙二醛含量(μmol/g)降低(肝、脾、脑分别为2.26±0.31,2.98±0.37,2.79 ±0.37),与苯染毒组相比,差异有显著性(q=4.00～8.04,P＜0 05).结论番茄红素能够减轻苯染毒引起的脂质过氧化,提高小鼠机体的抗氧化能力,增强抗氧化酶的活力.     

Latent overexpression of hepatic CYP2C7 in adult male and female rats neonatally exposed to phenobarbital: a developmental profile of gender-dependent P450s

For more than 20 years it has been known that neonatal exposure to phenobarbital results in a delayed, but permanent overexpression of drug-metabolizing enzymes in adult male and female rats. Accordingly, to identify the specific isoform(s) of P450 responsible for the imprinted overexpression of hepatic monooxygenases, we have monitored the developmental profile of some dozen hepatic P450 isoforms in 4- to 150-day-old male and female rats neonatally treated with the barbiturate. Some of the cytochrome P450s (CYP), i. e., CYP2A1, 2A2, 2C6, 3A1, and 3A2, exhibit the typical transient response in which isoform levels (mRNA, protein, and/or specific catalytic activity) rise precipitously at the time of phenobarbital administration and rapidly decline to preinduction levels after withdrawal of the barbiturate. Other isoforms, i.e., CYP1A1, 1A2, 2C7, 2C11, 2C12, and 2C13, were neither constitutively expressed nor phenobarbital inducible in the neonate. Only one of these isoforms, female predominant (M:F, approximately 1:2) CYP2C7, exhibited a barbiturate-induced delayed, but persistent approximately 30 to 50% overexpression from puberty through adulthood. We propose that at the time of exposure, neonatally administered phenobarbital produces a "silent" programming defect resulting in a delayed, but persistent overexpression of the isoform, contributing, at least in part, to a permanent elevation of hepatic drug-metabolizing enzyme activities.     

Effect of berberine on hepatocyte proliferation,inducible nitric oxide synthase expression,cytochrome P450 2E1 and 1A2 activities in diethylnitrosamine- and phenobarbital-treated rats

This study investigated the effect of berberine on the early phase of hepatocarcinogenesis stimulated by diethylnitrosamine (DEN, 150 mg/kg, 4 weeks) plus phenobarbital (PB, 75 mg/kg, 7 days) in rats. The expressions of proliferating cell nuclear antigen (PCNA) and inducible nitric oxide synthase (iNOS) were evaluated by immunohistochemistry. The activities of CYP isoenzymes were analyzed using different probe drugs including chlorzoxazone (CYP2E1) and phenacetin (CYP1A2) by high-performance liquid chromatography (HPLC) in vivo or in vitro. Results showed that the expressions of PCNA and iNOS were induced by DEN plus PB in liver tissues. Oral administration of berberine (50 mg/kg) inhibited the hepatocyte proliferation and iNOS expression, decreased cytochrome P450 content, inhibited activities of CYP2E1 and CYP1A2 in DEN-plus-PB-treated rats in vivo. Moreover, berberine (10, 50 and 100 μM) inhibited the activities of CYP2E1 and CYP1A2 in microsomes isolated from DEN-plus-PB-treated rats in vitro, suggesting that anti-hepatocarcinogenetic potential of berberine might be due to inhibiting oxidative metabolic activities of CYP 2E1 and CYP1A2, and decreasing NO production in rats.