大黄素对环孢素A在大鼠体内的药代动力学

目的评价中药成分大黄素对大鼠灌服环孢素A(CsA)的药代动力学。方法 60只雄性SD大鼠按体重进行随机分为5组,分别灌服CsA+60 mg.kg-1高剂量蒸馏水;CsA+30 mg.kg-1低剂量酮康唑;CsA+大黄素(60 mg.kg-1);CsA+大黄素(30 mg.kg-1);1～3 d大黄素,第4 d灌服CsA+大黄素。用HPLC-MS法测定全血中CsA的浓度,kinetica软件计算主要药代动力学参数,用SPSS17.00进行统计学分析。结果阳性对照组与空白对照组药代动力学参数除吸收速率外均有显著性差异;高剂量大黄素组使其较快达到峰浓度(P<0.05);低剂量大黄素组药代动力学参数与空白对照组比较无显著性差异;服用3 d大黄素后,最后1 d灌服CsA+大黄素组的吸收速率和峰浓度与空白对照组比较有显著性差异(P<0.05)。结论大黄素对CsA的生物利用度和代谢无明显影响。     

肾移植受者环孢素A与盐酸小檗碱合用的临床研究

目的:研究肾移植受者长期联合应用盐酸小檗碱(berberine hydrochloride,Ber)与环孢素A(Cyclos- porin A,CsA)对CsA血浓度和肝、肾功能的影响。方法:138名服用CsA Ber患者为试验组,150名单服CsA患者为对照组,以CsA全血浓度及肝、肾功能生化检测指标作为临床评价指标。结果:试验组合用Ber 1、3、6个月后CsA浓度比合用前增加49.8%、81.4%和36.9%(P<0.01),CsA浓度/剂量的比值比合用前增加88.8%、102.0%和72.5%(P<0.01),与对照组比较差异均有统计学意义(P<0.01)。Ber与CsA合用对肝、肾功能无明显影响。结论:Ber能明显升高肾移植受者CsA血浓度.且不增加CsA的毒性反应,因此可减少CsA用药量,节省费用。     

地奥心血康在兔体内对环孢素药动学的影响

目的: 研究地奥心血康(DAX)对环孢素(CsA)血药浓度及其药动学参数的影响.方法: 采用高效液相色谱法(HPLC)对单用CsA(组Ⅰ)及DAX与CsA合用(组Ⅱ)后家兔体内CsA全血浓度进行测定,并对两组药动学参数进行统计学分析.结果: DAX可使CsA的 Cmax、AUC显著增大(P＜0.05),其余药动学参数无显著变化.结论: CsA与DAX合用时,需对CsA进行血药浓度监测.     

环孢素A对家兔红细胞膜流动性的影响

目的：研究环孢素A对家兔红细胞膜流动性的影响。方法：以DPH作为荧光探针,采用荧光偏振法观察CsA对家兔红细胞膜流动性的影响。同时采用荧光偏振免疫分析法（FPIA）对家兔体内CsA全血药物浓度进行测定。结果：家兔体内高浓度的CsA使红细胞膜流动性显著降低,随着家兔体内CsA浓度的降低,红细胞膜流动性恢复近于正常水平,在此过程中膜流动性存在反弹现象,结论：环孢素A可使细胞膜流动性改变,长期大剂量服用环孢素A可引起红细胞膜损伤,膜流动性降低,这可能是环孢素A肝肾毒性产生的原因之一。     

Effect of probucol on the oral bioavailability of cyclosporine A.

We have previously reported the reduction in oral bioavailability of cyclosporine A (CsA) by probucol, a lipid-lowering drug. To evaluate the mechanism, we examined the effect of probucol on the transport of CsA across Caco-2 cell monolayers, on the influence of CsA pharmacokinetics in rats, and on the change of ultraviolet-absorption spectrum of the drug. Pretreatment with probucol (50 microM) inhibited (P < 0.001) both the apical-to-basal (-73.1%) and basal-to-apical (-77.8%) fluxes of [3H]-CsA. In rats, probucol orally given 6 h after, but not simultaneous with CsA did not decrease peak CsA concentration or area under the blood CsA concentration-time curve following a single oral dosing of CsA after the pretreatment with probucol for 7 days. These data indicate that P-glycoprotein-mediated active transport from intracellular to apical is not involved in the mechanism of probucol-CsA interaction, and absorption of CsA decreases in the presence of probucol in the gastrointestinal tract. In difference spectral analysis, probucol reduced the absorption peak of CsA in a concentration-dependent manner, indicating that probucol could form a complex with CsA. These results suggest that probucol interferes with CsA absorption probably by physicochemical mechanism such as complex formation, but not the enhancement of P-glycoprotein function.     

内皮源性舒张因子在环孢素A肾毒性发生中的作用

利用环孢素Ａ（ＣｓＡ）致大鼠离休灌注肾急性血流动力学障碍模型研究了内皮源性舒张因子（ＥＤＲＦ）在ＣｓＡ致肾毒性发生中的作用。结果表明，ＳＯＤ能缓解ＣｓＡ所致ＩＰＫ急性血流动力学障碍，Ｈｂ使ＣｓＡ对肾血管收缩作用加强，内皮依赖性血管扩张剂乙酰胆碱对ＣｓＡ预先处理的ＩＰＫ无反应，而非内皮依赖性扩血管剂硝酸甘油可逆转ＣｓＡ致ＩＰＫ血流动力学障碍，上述结果有力地提示ＣｓＡ致内皮细胞受损，ＥＤＲＦ释放减少可能介导了ＣｓＡ肾毒性的发生。     

精氨酸、尼莫地平、细胞生长肽对环孢素毒性及其血药浓度的影响

目的：探讨精氨酸、尼莫地平、细胞生长肽(bFGF)对环孢素的肝、肾、睾丸毒性的防护作用和对体内药物浓度的影响。方法：雄性大鼠给予环孢素后，再分别给予精氨酸、尼莫地平和bFGF，测定大鼠环孢素浓度、细胞凋亡指数、血清谷丙转氨酶(ALT)、肌肝(Cr)、生精功能等。结果：精氨酸明显升高大鼠血中环孢素浓度，尼莫地平和bFGF则降低环孢素浓度。精氨酸、尼莫地平和bFGF具有明显降低肝、肾、睾丸细胞凋亡指数、血清ALT和Cr，以及减轻精子发生障碍的作用。结论：精氨酸、尼莫地平、bFGF可影响血中环孢素浓度，并减轻环孢素引起肝、肾、睾丸的毒性，而以精氨酸的作用较明显。     

Correlation between pretransplantation test dose cyclosporine pharmacokinetic profiles and posttransplantation sirolimus blood levels in renal transplant recipients

We sought to determine whether pretransplantation test dose pharmacokinetic measurements of cyclosporine (CsA) concentrations would forecast the posttransplantation blood concentrations of sirolimus in renal transplant patients treated de novo with CsA, sirolimus, and prednisone. All 44 renal transplant recipients enrolled in Phase I/II studies of de novo posttransplantation therapy with sirolimus, CsA, and prednisone underwent pretransplantation pharmacokinetic profiling after having received paired intravenous (i.v.) and oral test doses of CsA. After transplantation, all patients were treated with CsA on a once- or twice-daily schedule (according to a concentration-controlled regimen), with tapering doses of prednisone, and with fixed doses of sirolimus on a once-daily schedule. Patients were divided into four cohorts based on the deviation of their pretransplantation CsA clearance or bioavailability values from the mean. Patients with high pretransplantation CsA clearance rates displayed a significantly lower mean posttransplantation value of sirolimus trough concentrations than patients with low pretransplantation CsA clearance rates. In contrast, values for pretransplantation absolute oral CsA bioavailability failed to correlate with the mean posttransplantation concentration of sirolimus but did predict posttransplantation CsA bioavailability. Therefore, pretransplantation CsA clearance rate estimates may forecast posttransplantation sirolimus concentrations, possibly guiding use of sirolimus therapy to achieve an optimal ratio of concentration-dependent immunosuppressive versus toxic effects.     

Effect of the six-mer synthetic peptide (AT1002) fragment of zonula occludens toxin on the intestinal absorption of cyclosporin A

Zonula occludens toxin (Zot) and its biologically active fragment, delta G, have been shown to reversibly open tight junctions (TJ) in endothelial and epithelial cells. Recently, a six-mer synthetic peptide H-FCIGRL-OH (AT1002) was identified and synthesized that retains the Zot permeating effect on intercellular TJ. The objective of this study was to evaluate the biological activity of AT1002 on enhancing the oral administration of cyclosporin A (CsA). The intestinal permeability enhancing effect of AT1002 on the transport of CsA across Caco-2 cell monolayers was examined after the following treatments, i.e., CsA, CsA/protease inhibitors (PI), CsA/PI/benzalkonium chloride (BC), CsA/AT1002, CsA/PI/AT1002, and CsA/PI/BC/AT1002 (CsA 0.5 microCi/ml, PI (bestatin 15 mM and E-64 5mM), BC 0.005 w/v%, and AT1002 5mM, respectively). Apparent permeability coefficients (P app) were calculated for each treatment. In addition, four treatments, i.e., CsA, CsA/PI/BC, CsA/AT1002, and CsA/PI/BC/AT1002 (CsA 120 microCi/kg, PI (bestatin 30 mg/kg and E-64 10mg/kg), BC 0.1 w/v%, and AT1002 doses of 5, 10 or 40 mg/kg, respectively) were prepared and administered intraduodenally to male Sprague-Dawley rats (230-280 g, n=4-5). Blood samples were collected at 0, 20, 60, and 120 min post-dosing and CsA plasma concentrations were determined subsequently using a Beckman Liquid Scintillation Counter. No significant increases in CsA transport were observed in the Caco-2 cell culture experiments following pre-treatment with AT1002 (5mM). Even though, AT1002 appeared to increase the P app of CsA in each treatment (CsA/AT1002, 1.54+/-0.13 x 10(-6)cm/s and CsA/PI/AT1002, 1.76+/-0.05 x 10(-6)cm/s) compared to each control (CsA and CsA/PI), respectively. The plasma concentration of CsA was significantly increased over a range of 1.55-2.50 at 10 and 40 mg/kg dose of AT1002. Also, AUC 0-120 min of CsA over a range of 1.64-2.14 and the Cmax of CsA over a range of 1.77-2.56 was statistically and significantly increased at 10 and 40 mg/kg of AT1002 after the intraduodenal administration of CsA/PI/BC/AT1002 to Sprague-Dawley rats. AT1002 significantly increased the in vivo oral absorption of CsA in the presence of PI. This study suggests that AT1002-mediated tight junction modulation, combined with metabolic protection and stabilization, may be used to enhance the low oral bioavailability of certain drugs when administered concurrently.     

口服小柴胡冲剂对肾移植病人环孢素A血药浓度的影响

目的:观察口服小柴胡冲剂对全血CsA浓度的影响。方法:13例肾移植术后病人口服CsA达稳态时,用荧光偏振免疫分析法(FPIA)测定口服小柴胡冲剂前后全血CsA浓度。结果:服药后比服药前全血CsA浓度明显增高,两者差异有显著性(P<0.05)。结论:在同时服用小柴胡冲剂时应监测CsA浓度和及时调整CsA给药方案。     

羟基喜树碱对家兔环孢A代谢和红细胞膜脂流动性的影响

目的　研究羟基喜树碱 (HCPT )对家兔环孢素A(CsA)药物动力学及对红细胞膜流动性 (LFU)的影响。方法　用TDX快速测定CsA全血药物浓度 ,用DPH荧光探针法测定红细胞膜流动性。结果　HCPT可使CsA的a ,V(c) ,K12 及CL(s)降低 ,T1/ 2 (a) 增加 (P <0 0 5 )。联合给药组的CsA血药浓度在给药后的 0 2 5 ,0 5和 1h高于单独给药组 ,且在 1h时差异有显著性 (P <0 0 5 )。联合给药组的LFU值在给药后的 0 5 ,1 0 ,1 5h时高于单独给药组 (P <0 0 5 ) ,与对照组差异无显著性。单独给药组的LFU值在给药后的 0 5 ,1 0 ,1 5h时低于对照组。结论　HCPT与CsA合用可提高CsA的血药浓度 ,有一定的临床应用前景     

国产环孢素A对小鼠免疫功能的抑制作用

当剂量为25～100mg/kg·d~(-1),ig×4d时,国产环孢素A(CsA)显著抑制小鼠脾脏空斑形成细胞数和溶血素生成,并呈剂量依赖方式。该剂量给药10d,可显著抑制2,4—二硝基氯苯所致小鼠迟发型皮肤超敏反应。CsA(50 mg/kg·d~(-1),ig×14d)能明显延长小鼠移植心脏的存活时间。CsA(50,100mg/kg·d~(-1),ig×4d)对小鼠iv碳粒廓清速率和骨髓细胞数均无明显影响。国产CsA和进口CsA对小鼠脾脏空斑形成细胞反应的抑制作用无显著差异。     

Cyclosporin A aerosol improves the anticancer effect of paclitaxel aerosol in mice.

The objective of this study was to assess the effect of cyclosporin A liposome aerosol on the anticancer activity of paclitaxel (PTX) liposome aerosol against renal cell carcinoma (Renca) pulmonary metastases in mice. Cyclosporin A (CsA) was administered as a liposome aerosol for one-half hour before starting one-half hour treatment with PTX liposome aerosol (CsA/PTX), and in a second groups of animals cyclosporin A liposome aerosol was given before PTX for one-half hour and also later by mixing a second dose of cyclosporin A aerosol with PTX aerosol and extending the treatment period to one hour (CsA/PTX + CsA). In one experiment, PTX and CsA/PTX aerosols were significantly more effective compared to untreated controls against renal cell cancer as measured by lung weights and tumor surface areas. CsA/PTX was significantly better that PTX alone as measured by lung weights and tumor area. In a second experiment, tumor areas of PTX and CsA/PTX treated mice were significantly reduced compared to untreated controls and CsA/PTX treated mice had significantly smaller tumor areas than PTX treated mice. In contrast, tumor numbers were not significantly fewer than controls in either therapeutic group. In a third experiment, tumor numbers and tumor areas were significantly fewer in mice treated with CsA/PTX and CsA/PTX + CsA compared to untreated controls. Mice treated with CsA/PTX + CsA had significantly fewer tumors and less tumor area than mice receiving CsA/PTX. While PTX treated mice were not different than untreated controls with respect to tumor numbers or tumor volumes, PTX treated mice had significantly greater tumor numbers and tumor areas than CsA/PTX and CsA/PTX + CsA treated mice. Co-administration of CsA with PTX demonstrated significant dose dependent anticancer effects against renal cell pulmonary metastases in mice. Toxicity manifested by weight loss was associated with the highest dose of CsA.     

In vitro evaluation of the effect of cyclodextrin complexation on pulmonary deposition of a peptide, cyclosporin A

The effect of hydroxypropyl-alpha-cyclodextrin (HP-alpha-CD) complexation on in vitro pulmonary deposition of a cyclic peptide cyclosporin A (CsA) was studied. In addition, the effect of storage (32 days, 40 degrees C, 75% RH) on CsA/HP-alpha-CD complexes was studied. The complexation of CsA with CDs was evaluated by a phase-solubility method. Solid CsA/HP-alpha-CD complexes were prepared by freeze drying. Three inhalation formulations were prepared: CsA/lactose reference formulation (LF) (drug:carrier 1:364, w/w), CsA/HP-alpha-CD complex formulation (CDF) (drug:CD 1:269, w/w) and CsA/HP-alpha-CD complex/lactose formulation (CDLF) (complex:carrier 100:114, w/w). The inhalation studies were performed in vitro using Andersen Sampler (Ph. Eur.) and Taifun multi-dose dry powder inhalers (DPIs). Before the storage, the respirable fraction value (RF%) of CsA was 19.8+/-0.7%, 33.0+/-7.0% and 34.6+/-1.1% (mean+/-S.D., n=4 x 20) with LF, CDF and CDLF, respectively. When exposed to moisture (storage in a permeable polystyrene tube), the RF% values of CsA from formulations containing CsA/HP-alpha-CD complexes were lower than before the storage. However, when stored in the Taifun DPI, the RF% value of CsA from any of the formulations did not decrease. In conclusion, an acceptable RF% value of a peptide CsA from freeze-dried, simply micronized CsA/HP-alpha-CD complex powder was achieved before and after storage in the DPI.     

环孢素A血药浓度的影响因素探讨

目的：对影响CsA血药浓度的因素进行初步探讨。方法：采用FPIA法测定132例肾移植受者的CsA血药浓度，观察肝功能等对CsA血药浓度的影响。结果：肝功能异常，合并应用酮康唑、氟康唑、地尔硫、异烟肼及雷尼替丁等药物均可使CsA血药浓度显著升高，腹泻、喝浓茶等可使CsA血药浓度显著降低。此外，在术后早期部分患者CsA血药浓度与血RBC及HGB含量有显著正相关。结论：监测CsA血药浓度必须结合患者的实际情况具体分析，及时调整用药方案。     

Explaining variability in ciclosporin exposure in adult kidney transplant recipients

Purpose

Optimal ciclosporin A (CsA) exposure in kidney transplant recipients is difficult to attain because of variability in CsA pharmacokinetics. A better understanding of the variability in CsA exposure could be a good means of individualizing therapy. Specifically, genetic variability in genes involved in CsA metabolism could explain exposure differences. Therefore, this study is aimed at identifying a relationship between genetic polymorphisms and the variability in CsA exposure, while accounting for non-genetic sources of variability.

Methods

De novo kidney transplant patients (n?=?33) were treated with CsA for 1 year and extensive blood sampling was performed on multiple occasions throughout the year. The effects of the non-genetic covariates hematocrit, serum albumin concentration, cholesterol, demographics (i.e., body weight), CsA dose interval, prednisolone dose and genetic polymorphisms in genes encoding ABCB1, CYP3A4, CYP3A5, and PXR on CsA pharmacokinetics were studied using non-linear mixed effect modeling.

Results

The pharmacokinetics of CsA were described by a two-compartment disposition model with delayed absorption. Body weight was identified as the most important covariate and explained 35% of the random inter-individual variability in CsA clearance. Moreover, concurrent prednisolone use at a dosage of 20 mg/day or higher was associated with a 22% higher clearance of CsA, hence lower CsA exposure. In contrast, no considerable genotype effects (i.e., greater than 30–50%) on CsA clearance were found for the selected genes.

Conclusions

It appears that the selected genetic markers explain variability in CsA exposure insufficiently to be of clinical relevance. Therefore, therapeutic drug monitoring is still required to optimize CsA exposure after administration of individualized doses based on body weight and, as this study suggests, co-administration of prednisolone.     

Development of cyclosporin A-loaded hyaluronic microsphere with enhanced oral bioavailability

To develop a hyaluronic microsphere with the improved oral bioavailability of poorly water-soluble cyclosporin A (CsA), the microspheres were prepared with varying ratios of sodium hyaluronate (HA)/sodium lauryl sulfate (SLS)/CsA using a spray-drying technique. The effects of HA and SLS on the dissolution and solubility of CsA in microspheres were investigated. The CsA-microsphere prepared with HA/SLS/CsA at the ratio of 4/2/1 gave the highest solubility and dissolution rate of CsA among those formulae tested. As solubility and dissolution rate of CsA were increased about 17- and 2-fold compared to CsA powder, respectively, this CsA-microsphere was selected as an optimal formula for oral delivery in rats. The CsA-microsphere and Sandimmun neoral sol gave significantly higher blood levels compared with CsA powder alone. Moreover, the AUC, T(max) and C(max) values of CsA in CsA-microsphere were not significantly different from those in Sandimmun neoral sol in rats, indicating that CsA-microsphere was bioequivalent to the commercial product in rats. Our results demonstrated that the CsA-microsphere prepared with HA and SLS, with improved bioavailability of CsA, might have been useful to deliver a poorly water-soluble CsA.     

Bioavailability of cyclosporin A dispersed in sodium lauryl sulfate-dextrin based solid microspheres

The purpose of this work was to develop a solid dispersion system containing cyclosporin A (CsA) in order to improve the bioavailability of poorly water-soluble CsA. Solid dispersion systems that are spherical in shape (CsA-microspheres) were prepared with varying ratios of CsA/sodium lauryl sulfate/dextrin using a spray-drying technique. The effects of sodium lauryl sulfate (SLS) and dextrin on the dissolution of CsA dispersed in SLS-dextrin based solid microspheres were investigated. The bioavailability of CsA-microspheres was compared with CsA powder alone and commercial Sandimmun in dogs. SLS significantly enhanced the dissolution of CsA from microspheres, while dextrin did not affect this. The CsA-microspheres at the CsA/SLS/dextrin ratio of 1/3/1, which gave the highest dissolution rate of CsA among the formula treated, was selected as an optimal formula for oral delivery. This formula gave significantly higher blood levels, area under the drug concentration-time curve (AUC) and maximum blood concentration of drug (Cmax) of CsA in dogs compared with the CsA powder alone. The AUC, Cmax and time to reach maximum blood concentration (Tmax) of CsA with CsA-microspheres was not significantly different from those after oral administration of Sandimmun, suggesting the similar bioavailability to Sandimmun in dogs. Our study demonstrates that the CsA-microspheres prepared with SLS and dextrin, with improved bioavailability of CsA, would be useful to deliver a poorly water-soluble CsA and could be applicable to other poorly water-soluble drugs.     

载环孢素纳米球的制备及释放特性*

目的：制备一种环孢素A（CsA）缓释纳米体系。方法：以PLA-co-PEG共聚物材料作为环孢素药物的释放载体；采用超声振荡技术制备载环孢素的PLA—PEG—PLA纳米球；分析纳米球的粒径与分布以及纳米球降解过程中的形貌变化；体外释放试验探讨制备的纳米球的降解特性以及与载体材料、介质pH值之间的影响关系；小鼠灌胃后HPLC法测定血药浓度。结果：采用PLA—PEG—PLA共聚材料装载CsA，药物包封率达到89．2％。纳米球平均粒径为242．3nm，载药后平均粒径增大到320．2nm。扫描电镜分析发现纳米球在磷酸缓冲液中溶胀程度与降解速率依赖于介质pH值。体外模拟释放表明载药纳米球的药物释放速率与载体降解速率一致，持续稳定释药时间〉7d。动物模型也证实该载CsA纳米球可维持血液中稳定的药物浓度5d以上。结论：利用本方法制备的载CsA纳米球是一种较理想的环孢素药物剂型，具有临床应用价值。     

环孢素A调节自噬对人滋养细胞氧化应激损伤的影响

目的探讨环孢素A(CsA)调节自噬对人滋养细胞氧化应激损伤的保护作用。方法将细胞分为对照组、氧化应激组、低剂量CsA(2μmol/L)组和高剂量CsA(4μmol/L)组。流式细胞仪检测HTR-8/SVneo滋养细胞凋亡,硫代巴比妥酸比色法检测丙二醛(MDA),化学比色法检测超氧化物歧化酶(SOD),化学荧光法检测活性氧(ROS),Western blot检测蛋白表达。结果对照组、氧化应激组、低剂量CsA组和高剂量CsA组HTR-8/SVneo细胞凋亡率分别为4.24%±0.72%、38.15%±4.63%、27.24%±3.16%、18.45%±2.28%,各组间比较差异有统计学意义(P<0.01)。CsA组细胞MDA和ROS显著低于氧化应激组(P<0.01),且高剂量CsA组低于低剂量CsA组(P<0.01);CsA组细胞SOD显著高于氧化应激组(P<0.01),且高剂量CsA组高于低剂量CsA组(P<0.01)。对照组、氧化应激组、低剂量CsA组和高剂量CsA组HTR-8/SVneo细胞自噬蛋白LC3Ⅱ表达的相对灰度值分别为0.23±0.05、0.11±0.02、0.38±0.07、0.75±0.13,各组间比较差异有统计学意义(P<0.01)。结论CsA可以增强滋养细胞自噬,对氧化应激损伤诱发的滋养细胞凋亡起到抑制作用。