Changes in microsomal activity in alcoholism and obesity

BACKGROUND: Liver damage is more prevalent among obese alcoholics, and cytochrome P-4502E1(CYP2E1) induction is involved in its pathogenesis. OBJECTIVES: The study was undertaken to assess microsomal function, in alcoholic and nonalcoholic male subjects with different body compositions, through pharmacokinetics of chlorzoxazone (CLZ). We also intended to study the relationship between CLZ hydroxylation and urinary levels of 8-hydroxydiguanosine, and between CLZ levels and liver histology. METHODS: Serial measurements of CLZ serum concentration, after a 750 mg dose, were performed in 17 alcoholics (9 normal weight and 8 obese) and 21 nonalcoholic subjects (10 normal weight and 11 obese). Concentration of 6-hydroxy-chlorzoxazone (6-OH-CLZ) was determined at the second hour. Anthropometry, clinical laboratory tests, and urinary 8-hydroxydiguanosine concentrations were measured. Liver biopsies were performed in alcoholics. RESULTS: Five biopsies revealed severe lesions, one in normal-weight and four in obese patients (p = NS). Area under the curve (AUC) of CLZ was higher in normal-weight controls compared with the rest of the groups (ANOVA p = 0.001). This parameter correlated negatively with adiposity in nonalcoholic subjects and did not correlate with liver histology. 6-OH-CLZ/CLZ ratio was lower in normal-weight controls, compared with obese subjects and normal-weight alcoholics (p = 0.02). Both alcoholism and obesity were included as predictors of CLZ AUC in a multiple regression analysis. The two-factor ANOVA showed an additive effect of centripetal body fat distribution and alcoholism. Urinary 8-hydroxydiguanosine levels were extremely variable. CONCLUSIONS: Centripetal adiposity and alcoholism are associated with induction of CYP2E1. This may explain the higher prevalence of liver damage among obese alcoholics and also nonalcoholic steatohepatitis.     

帕罗西汀和多虑平联合氯唑沙宗治疗伴有焦虑抑郁情绪的紧张型头痛的临床对照研究

目的比较帕罗西汀和多虑平联合氯唑沙宗治疗伴有焦虑抑郁情绪的紧张型头痛的临床疗效及安全性。方法选择在我科门诊治疗伴有焦虑抑郁情绪的紧张型头痛患者56例为研究对象,采用随机数字表法分为帕罗西汀组和多虑平组,每组28例,帕罗西汀组在常规服用氯唑沙宗的基础上加服帕罗西汀治疗,多虑平组加服多虑平治疗,另外回顾以往常规应用氯唑沙宗治疗的伴有焦虑抑郁情绪的紧张型头痛患者30例的临床资料,并作为对照组。分别对治疗12周后三组患者头痛、焦虑抑郁情绪改善情况及药物不良反应发生情况进行评价,并进行对比分析。结果所有患者均顺利完成12周的治疗,治疗后帕罗西汀组显效率和总有效率均明显高于对照组,差异均有统计学意义(P<0.05或P<0.01);帕罗西汀组患者总有效率略高于多虑平组,但差异无统计学意义(P>0.05),而帕罗西汀组显效率明显高于多虑平组,差异有统计学意义(P<0.05);多虑平组显效率与对照组相当,总有效率高于对照组,但差异无统计学意义(P>0.05)。帕罗西汀组和多虑平组患者HAMA评分和HAMD评分均较治疗前明显改善(P<0.01),且改善程度明显优于对照组(P<0.05);与多虑平组相比,帕罗西汀组HAMA和HAMD评分改善更为明显,差异均有统计学意义(P<0.05)。帕罗西汀组和对照组不良反应发生率和不良反应严重程度评分均明显低于多虑平组(P<0.05或P<0.01);而帕罗西汀组和对照组间差异无统计学意义(P>0.05)。结论帕罗西汀联合氯唑沙宗治疗伴有焦虑抑郁的紧张型头痛的临床疗效满意,不良反应少,且较轻微,值得临床推广应用。     

CYP2E1 activity in patients with alcoholic liver disease

Background/Aims: In addition to the possible toxicological impact of cytochrome P4502E1 (CYP2E1) in alcohol-induced liver damage, its activity can be regarded as a variable for dug action in patients with alcoholic liver disease as CYP2E1 is involved in the metabolism of several drugs, for example, paracetamol and halogenated anesthetics. The purpose of our study was to acquire detailed knowledge of CYP2E1 activity in patients with progressingly severe manifestations of alcoholic liver disease.Methods: The concentration ratio of 6-hydroxy-chlorzoxazone/chlorzoxazone in plasma 2 h after ingestion of 500 mg chlorzoxazone (so-called metabolic ratio) has been shown to reflect CYP2E1 activity in vivo. We examined CYP2E1 activity in 56 Caucasian inpatients with minor (n=20), more pronounced (n=14) and severe alcoholic liver disease (n=22). Alcohol abusers were compared to healthy teetotallers (n=14).Results: Metabolic ratios were increased 3-fold in actively drinking (ethanol-induced) compared to abstaining (non-induced) patients with alcoholic liver disease (1.19±0.84 vs. 0.44±0.45, mean±SD, (p<0.0001). CYP2E1 activity was significantly lower in non-induced patients with severe alcoholic liver disease (0.19±0.10) than in healthy controls (0.50±0.28, p<0.01), abstaning alcohol abusers with minor (0.67±0.60, p<0.01) and more pronounced alcoholic liver disease (0.53±0.31, p<0.01). When non-induced patients with alcoholic liver disease were arranged in progressing order of liver damage (minor, more pronounced, severe alcoholic liver disease), there was a significant decline in CYP2E1 activity (p=0.0008).Conclusions: In non-induced patients, CYP2E1 activity decreases in line with severity of alcoholic liver disease. CYP2E1-mediated drug metabolism is significantly impaired in severe alcoholic liver disease.     

Predicting the hepatic clearance of xenobiotics in humans from in vitro data

Values for V_max and K_m determined during the in vitro metabolism of a xenobiotic to a known metabolite by a specific human isozyme of cytochrome P450 (P450) were used to predict the hepatic clearance (CL_H) of the xenobiotic to that metabolite. The calculated CL_H values were then compared to literature values of clearance (CL) to the same metabolite obtained during pharmacokinetic studies in humans. For the 6-hydroxylation of chlorzoxazone (P450 2E1) the predicted and actual clearances were 110±77 mL min^?1 and 110 mL min^?1, respectively. For the 6β-hydroxylation of cortisol, the deethylation of lidocaine (two studies), and the oxidation of nifedipine (all P450 3A3/4) the values were 13±15 mL min^?1 and 13 mL min^?1; 758±282 or 829±283 mL min^?1 and 875 mL min^?1; and 284±176 mL min^?1 and 294 mL min^?1, respectively. An increase to 72±25 mL min^?1 in the CL_H of cortisol to 6β-hydroxycortisol was calculated following rifampicin treatment. Finally, the polymorphic nature of the metabolism (P450 2D6) of mexiletine was confirmed. The usefulness of the method and its limitations are discussed.     

系数倍率法测定复方氯唑沙宗片中两组分的含量

【目的】建立复方氯唑沙宗片中氯唑沙宗和对乙酰氨基酚的系数倍率测定法。【方法】用BASIC语言编制程序选择最佳测定波长对，以消除二组分的相互干扰，不经提取分离同时测定复方氯唑沙宗片中二组分的僮。【结果】氯唑沙宗和对乙酰氨基酚的平均回收率和相对标准偏差分别为100．0％，0．70％和100．1％，0．88％。【结论】该方法简便、快速、结果满意。     

高效液相色谱法测定复方氯唑沙宗片中两组分血药浓度

目的:研究建立测定血浆中复方氯唑沙宗片两组分浓度的HPLC-UV法。方法:反相高效液相色谱法测定血浆中药物的浓度。Zorbax XDB-C18色谱柱,血浆样品经乙醚提取,空气吹干,加流动相溶解进样。氯唑沙宗的流动相为甲醇∶水=(60∶40),在波长282nm处检测;对乙酰氨基酚的流动相为甲醇∶水=(20∶80),在波长245nm处检测,以外标法计算。结果:氯唑沙宗在0.208～33.28μg/ml、对乙酰氨基酚在0.238～14.28μg/ml浓度范围内,样品的峰面积与对应浓度呈良好线性关系,r氯=0.9998,r对=0.9998。最低检测限均为0.1μg/ml,氯唑沙宗高、中、低(20.8μg/ml,4.16μg/ml,0.416μg/ml)3种浓度的方法回收率分别为(103.36±6.0)%,(99.51±1.2)%,(99.08±1.88)%;对乙酰氨基酚高、中、低(9.52μg/ml,2.38μg/ml,0.476μg/ml)3种浓度的方法回收率依次为(101.5±3.15)%,(97.6±1.93)%,(99±3.15)%,日内RSD分别为(1.2%～2.3%)、(1.4%～6.7%),日间RSD分别为(2.5%～5.1%)、(5%～7.8%)。结论:此法操作简便、结果可靠。     

局部注射曲安奈德配合口服氯唑沙宗治疗颈源性头痛

目的观察局部注射曲安奈德配合口服复方氯唑沙宗治疗颈源性头痛的疗效。方法选取46例确诊为颈源性头痛的门诊患者,随机分为观察组和对照组,每组23例。对照组采用颈椎横突注射法治疗,观察组加用复方氯唑沙宗片口服。治疗后以VAS评分、患者满意度、治愈率评估两组患者疗效。结果两组患者治疗后的VAS评分均较治疗前下降,差异有统计学意义(P<0.05),观察组VAS评分下降明显高于对照组[(6.12±1.79)vs(4.33±1.54),P<0.05],且两组患者满意度、治愈率的差异有统计学意义(P<0.05)。结论局部注射曲安奈德配合口服复方氯唑沙宗治疗颈源性头痛,可显著降低疼痛评分,提高治愈率和患者满意度。     

Cocktail法研究脉络宁注射液对大鼠CYP1A2、CYP2E1和CYP3A4活性的影响

目的：研究脉络宁注射液对大鼠CYP1A2、CYP2E1和CYP3A4活性的影响。方法：14只大鼠随机均分成临床等效剂量组和高剂量组,连续2周静脉给予脉络宁注射液（临床等效剂量纽,2mL／kg;高剂量组,4mL／kg）前后,均同时灌胃给予3个探针底物（茶碱,30mg／kg;氯唑沙宗,50rag／kg;氨苯砜,20mg/kg）,进行采血试验。用HPLC法同时测定大鼠体内各探针的血药浓度,DAS1．0软件计算药动学参数,并以配对t检验对各组大鼠前后两轮主要药动学参数进行差异性比较。结果：在1个给药疗程（14d）内,临床等效剂量组大鼠用药前后,3个探针的药动学参数均无显著性变化（P〉0．05）;高剂量组大鼠用药后,与用药前相比,茶碱的药动学参数没有显著变化（P〉0．05）;氨苯砜和氯唑沙宗的AUC0-24h均有升高趋势（P〈0．05）,给药后分别是给药前的1．44倍和1．28倍,同时氯唑沙宗的CL显著降低（P〈0．05）。结论：临床等效剂量脉络宁对大鼠CYP1A2、CYP2E1和CYP3A4活性均无显著影响,而高剂量脉络宁对大鼠CYP2E1和CYP3A4均有弱抑制作用。     

利用细菌/杆状病毒系统在昆虫细胞中表达人CYP2E1

目的获得人CYP2E1重组酶,并用该重组酶的特征性探针底物对其进行代谢活性研究.方法以人肝组织RNA为模板,通过RT-PCR得到CYP2E1 cDNA片断,然后与pFastBac质粒连接,得到pFastBac-CYP2E1重组质粒,将其转化E.coli DH 10Bac大肠杆菌,通过转座作用,获得重组Bacmid-CYP2E1,将其转染草地夜蛾细胞(Sf9) 后,产生重组杆状病毒.将该病毒以及分别含有人CYPOR和人CYPb5的病毒共同感染Sf9细胞,收集共表达蛋白,以氯唑沙宗为底物鉴定重组酶的活性.结果利用细菌/杆状病毒系统得到重组人CYP2E1的表达,其对氯唑沙宗的Km值为(72.4±8.7)μmol·L-1,Vmax值为(2.41±0.10)μmol·min-11·g-1蛋白.结论利用杆状病毒系统成功表达了有催化活性的人CYP2E1重组酶,其活性与文献报道值相似.