不同剂量染料木黄酮及其代谢产物在大鼠尿中的排泄

目的:研究不同剂量染料木黄酮及其葡萄糖醛酸化代谢产物在大鼠尿中的排泄动力学。方法:将染料木黄酮制成混悬液,按6.25、12.5、50mg.kg-1给大鼠灌胃,于灌胃后不同时间收集尿液,用葡萄糖醛酸酶溶液处理尿液。采用高效液相色谱法测定尿液中染料木黄酮及其葡萄糖醛酸化代谢产物的浓度。结果:6.25、12.5、50 mg.kg-1时,累积以原形经尿液排泄的药物分别为34.79±10.83、187.30±69.96和213.56±30.58μg,累积经尿液排泄的总药物(原形药物+葡萄糖醛酸化药物)分别为217.79±52.06、583.05±106.92和1108.37±88.14μg,累积经尿液排泄的葡萄糖醛酸化代谢产物分别占尿液排泄总量的84.03%、67.88%和80.73%。结论:染料木黄酮在大鼠尿液中主要以葡萄糖醛酸结合形式排泄,原形及其葡萄糖醛酸化代谢产物的排泄呈现明显的非线性剂量依赖性特征。     

染料木黄酮在Beagle犬体内代谢动力学的剂量依赖性研究

目的研究不同剂量染料木黄酮(genistein)在Beagle犬体内的药代动力学特征。方法将染料木黄酮制成混悬液，按2.67，5.34及10.68 mg·kg^-1给Beagle犬灌胃，于灌胃后不同时间在犬前腿部静脉采抗凝血标本，用葡糖醛酸酶溶液处理血浆。采用反相高效液相色谱法测定血浆中母体药物及葡糖醛酸结合型药物浓度，血浆药物浓度-时间数据用3P97药代动力学软件分析。结果染料木黄酮在Beagle犬体内过程符合二室开放模型，当剂量为2.67 mg·kg^-1时，母体药物MRT为52.9 min，AUC为6.7 mg·min·L^-1，葡糖醛酸结合型药物AUC为33.9 mg·min·L^-1；当剂量为5.34 mg·kg^-1时，母体药物MRT为224.8 min，AUC为26.1 mg·min·L^-1，葡糖醛酸结合型药物AUC为70.1 mg·min·L^-1；当剂量为10.68 mg·kg^-1时，母体药物MRT为267.7 min，AUC为33.2 mg·min·L^-1，葡糖醛酸结合型药物AUC为140.5 mg·min·L^-1。结论染料木黄酮首过代谢突出，血浆中药物主要以葡糖醛酸结合形式存在。在一定范围内随给药剂量增加，母体药物的吸收量趋于饱和，药物的血浆消除半衰期延长。     

大鼠灌胃四逆散提取物后血浆、尿液、粪便、胆汁中主要代谢产物的鉴定

采用UPLC-Q-TOF/MS研究四逆散提取物在大鼠体内的代谢产物,利用碰撞能量梯度(MSE)和质量亏损过滤(MDF)技术进行分析,鉴定大鼠灌胃四逆散提取物后血浆、尿液、粪便、胆汁中的代谢产物。四逆散提取物中柚皮苷、柚皮素、橙皮苷、新橙皮苷、甘草苷、甘草素、甘草酸、甘草次酸、柴胡皂苷a、柴胡皂苷d在大鼠不同代谢途径中推测出原形、羟基化、葡糖醛酸化、硫酸化、葡糖醛酸化与硫酸化结合、羟化葡糖醛酸化等共41个代谢产物。     

HPLC-ESI/MS分析5-羟基黄酮在大鼠体内的代谢产物

目的研究5-羟基黄酮在大鼠体内的代谢产物。方法应用高效液相色谱-电喷雾质谱(HPLC-ESI/MS)检测大鼠灌胃5-羟基黄酮后血浆、尿液、胆汁和粪便中的代谢产物。实验采用Zorbax C18色谱柱,0.05%甲酸乙腈-0.05%甲酸水二元线性梯度洗脱进行色谱分离,并与电喷雾质谱联用,根据正离子模式的分子离子峰获得化合物分子量信息,推测化合物的可能结构。结果仅在大鼠粪便中检测到原形成分,在大鼠尿液、粪便、血浆、胆汁中检测到5-羟基黄酮葡糖醛酸结合物。结论 5-羟基黄酮吸收差,在大鼠体内主要以II相代谢产物葡萄糖醛酸结合物的形式存在。     

鉴定大鼠注射绿原酸后体内的代谢产物

绿原酸为多种中药注射液的主要成分, 本文采用超高效液相色谱-四极杆飞行时间质谱法 (UPLC/Q- TOF MS) 鉴定大鼠注射给予绿原酸后胆汁、尿、粪和血浆中的代谢产物。利用碰撞能量梯度 (MS^E) 和质量亏损过滤 (MDF) 技术, 在大鼠胆汁、尿、粪和血浆中共检测到35种代谢产物。胆汁中主要代谢产物为O-甲基绿原酸谷胱甘肽结合物, 其排泄量超过胆汁中全部代谢物的80%, 尿中主要为原形、O-甲基结合物、水解代谢产物及葡糖醛酸结合物, 粪中主要为O-甲基结合物及其半胱氨酸结合物, 血浆中主要为原形化合物。绿原酸及其代谢产物经尿和粪便排泄比例相近。实验结果表明, 绿原酸在大鼠体内代谢广泛, 主要途径之一是与谷胱甘肽结合, 提示绿原酸的烯酮双键具有亲电性, 可能与蛋白的巯基共价结合, 导致过敏性不良反应, 应予以关注。     

染料木黄酮在雌雄大鼠肝微粒体中的代谢差异

目的研究染料木黄酮在♀、♂大鼠肝微粒体中的代谢差异。方法制备♀、♂大鼠肝微粒体,确定染料木黄酮代谢的酶动力学条件,分别用CYP1A2抗体和选择性CYP1A2抑制剂呋喃茶碱与大鼠肝微粒体和染料木黄酮共同温孵,测定染料木黄酮在♀、♂大鼠肝微粒体中的代谢速率,评价♀、♂大鼠CYP1A2的相对百分比活性。结果在CYP1A2抗体浓度为1∶400,孵育时间为30 m in条件下,♂大鼠肝微粒体代谢染料木黄酮的相对代谢率为(20.95±2.13)%,♀动物为(13.73±1.26)%。在选择性CYP1A2抑制剂呋喃茶碱浓度为3.125μmol.L-1,孵育时间为30 m in条件下,♂动物为(58.02±3.35)%,而♀大鼠肝微粒体代谢染料木黄酮的相对代谢率为(43.82±2.65)%,两者之间差异有显著性(P<0.01)。结论染料木黄酮在♂大鼠肝微粒体中代谢较♀大鼠快,提示♂大鼠肝微粒体CYP1A2酶活性高于♀大鼠。     

溴泰君在大鼠的组织分布和排泄

目的研究溴泰君(W198)在大鼠的组织分布和排泄，为临床试验提供依据。方法用HPLC紫外检测方法测定大鼠iv W198后生物样品中的药物含量。结果大鼠iv W198 20 mg·kg^-1后组织的药物含量远高于相同时间的血清药物浓度。药物主要分布在肺，其次在肾、心、肝等组织,大部分组织的药物含量于给药后0.25 h最高，给药后2 h显著下降，至24 h均缓慢下降；大鼠iv W198 20 mg·kg^-1后从尿、粪(0-96 h)和胆汁(0-24 h)中排泄的原型药物分别占给药总量的0.150%，2.1%和0.063%。结论W198主要分布于肺组织中。从尿、粪和胆汁中排泄的原型药物很少。     

液相色谱-串联电喷雾离子阱质谱法鉴定大鼠尿液中药根碱代谢物

目的研究药根碱在大鼠体内的主要代谢产物。方法健康大鼠尾静脉注射12 mg·kg^-1药根碱，收集0～72 h的尿样，尿样经C₁₈小柱固相萃取分离纯化后，经液相色谱-串联电喷雾离子阱质谱(LC-ESI/ITMSⁿ)分析鉴定其中的代谢物。代谢物的结构鉴定主要依据各代谢物与原药的一级质谱电离规律和二级或三级质谱裂解规律间的关联性。结果在大鼠尿样中检测到7种I相代谢产物(如原药的脱氢、脱甲基、羟基化代谢物)及11种II相代谢产物(如甲基化轭合物和葡糖醛酸轭合物)。结论本方法用于大鼠尿样中药根碱的代谢物研究不仅操作简单、快速，而且灵敏度高、专属性强。     

曲克芦丁及其代谢产物在大鼠体内的排泄动力学研究

目的研究曲克芦丁及其代谢产物在大鼠体内的排泄情况。方法大鼠腹腔注射曲克芦丁,收集尿液、粪便和胆汁样品,应用 HPLC方法测定曲克芦丁在大鼠尿液、粪便和胆汁样品的含量,测定曲克芦丁代谢产物在大鼠粪便中的含量。结果曲克芦丁在大鼠尿液、粪便和胆汁中的累积排泄率分别为( 16.17±10.28)%、(0.54±0.47)%和( 58.94±13.37)%。与此同时,粪便中约有( 22.69±12.48)%的代谢产物曲克芦丁苷元生成。结论曲克芦丁主要通过胆汁进行排泄,以原型和代谢产物的形式排出体外。     

β-榄香烯经大鼠呼吸道排泄研究

目的研究β-榄香烯自大鼠呼吸道排泄规律。方法采用自制的呼吸道药物收集装置，大鼠iv或ip β-榄香烯75 mg·kg^-1后，于不同时间点收集呼出气体，用气相色谱法测定药物浓度。结果大鼠iv或ip β-榄香烯75 mg·kg^-1 6 h后的累积排出量分别为给药剂量的1.41%和0.51%。结论原形药可经呼吸道排出，但不是β-榄香烯在大鼠体内消除的主要方式。     

Determination of the biliary excretion of piperacillin in humans using a novel method

AIM: To evaluate the applicability of a novel method to determine the biliary excretion of piperacillin. METHODS: Healthy volunteers were administered piperacillin i.v. Duodenal aspirates were collected via a custom-made oroenteric catheter; blood and urine also were collected. Gallbladder ejection fraction (EF) was determined by gamma scintigraphy and pharmacokinetic parameters were calculated using noncompartmental analysis. RESULTS: The fraction of the piperacillin dose excreted unchanged into bile was 1.1 +/- 0.3% (biliary clearance corrected for EF was 0.032 +/- 0.008 ml min(-1) kg(-1)). CONCLUSIONS: This methodology can be used to determine reliably the biliary clearance of drugs that are excreted only marginally into bile. Normalization of biliary clearance for EF significantly reduces intersubject variability of this parameter.     

Excretion and metabolism of intramuscularly administered [14C]-haloperidol decanoate in rats

Urinary, fecal and biliary excretion, together with enterohepatic circulation, of radioactivity were studied after intravenous (50 mg eq/kg) and intramuscular (5 and 50 mg eq/kg) administration of [14C]-haloperidol decanoate in rats. The composition of urinary and biliary metabolites was also examined. The rate of excretion after intravenous administration lowered rapidly with the half-life of about 1.5 days and about 95% of dose was excreted in excreta within 10 days. Shortly after intramuscular administration, the rate of excretion lowered rapidly but then more gradually later (half-lives after administration of 5 and 50 mg eq/kg were 16.4 and 11.2 days, respectively). About 90% of dose was excreted within 42 days after intramuscular administration. About 1.6% of dose/day was excreted in the bile during 15-17 days after intramuscular administration, of which about 30% was reabsorbed within 24 h (enterohepatic circulation). The major urinary metabolite was p-fluorophenylaceturic acid and the biliary metabolite, glucuronide and sulfate of haloperidol. No unchanged decanoate was detected in the excreta.     

Slow biliary elimination of methyl mercury in the marine elasmobranchs, Raja erinacea and Squalus acanthias

The present study examined the ability of two marine elasmobranchs (Raja erinacea, little skate, and Squalus acanthias, spiny dogfish shark) to excrete methyl mercury into bile, a major excretory route in mammals. 203Hg-labeled methyl mercury chloride was administered via the caudal vein, and bile collected through exteriorized cannulas in the free swimming fish. Skates and dogfish sharks excreted only a small fraction of the 203Hg into bile over a 3-day period: in the skate, the 3-day cumulative excretion (as a % of dose) was 0.44 +/- 0.10 (n = 4, +/- SD), 0.71 +/- 0.23 (n = 6), and 1.00 +/- 0.34(n = 4) for doses of 1, 5, and 20 mumol/kg, respectively, while the shark excreted only 0.15 +/- 0.15% (n = 8) at a dose of 5 mumol/kg. As in mammals, the availability of hepatic and biliary glutathione was a determinant of the biliary excretion of methyl mercury in these species: the administration of sulfobromophthalein, a compound known to inhibit both glutathione and methyl mercury excretion in rats, or of L-buthionine-S,R-sulfoximine, an inhibitor of glutathione biosynthesis, decreased the biliary excretion of both glutathione and mercury in the skate. The slow hepatic excretory process for methyl mercury in the skate and shark was attributed to an inordinately slow rate of bile formation: from 1 to 4 ml/kg X day. An inefficient biliary excretory process in fish may account in part for the long biological half-times for methyl mercury in marine species.     

The disposition of quinine in the rat isolated perfused liver: effect of dose size

We have investigated the pharmacokinetics of both free and total quinine in the rat isolated perfused liver at three doses, 6.25, 12.5 and 25 mg. The plasma concentrations of free and total quinine decayed biexponentially over 4 h. However, on increasing dose, the terminal half-life of free and total quinine showed marked increases ranging from 12.4 +/- 3.7 min at 6.25 mg to 176.0 +/- 153 min at 25 mg (total quinine). Quinine clearance was reduced approximately by half as the dose was doubled. At 10 min post dosage, quinine extraction at the 6.25 mg dose (56 +/- 16.3%) was more than twice that of the highest dose (25 mg, 25.0 +/- 6.5%). Free quinine at the 6.25 mg dose was cleared at approximately 100% of perfusate flow, whereas at 25 mg, clearance was less than one fifth of that value. Unchanged quinine elimination in bile was low, with less than 1% of the parent drug being detected at the 12.5 and 25 mg doses. Relatively little parent drug was recovered from the liver at 4 h. At the 25 mg dose, less than or equal to 6% was recovered as parent drug. HPLC analysis revealed some polar metabolites of quinine in the bile and in the liver homogenates. Dose dependent kinetics of quinine were demonstrated in this study, as hepatic extraction of quinine decreased with increasing dose and input concentration.     

Antitumor efficacy of AG3340 associated with maintenance of minimum effective plasma concentrations and not total daily dose, exposure or peak plasma concentrations

Oral administration of AG3340, a novel metalloprotease (MMP) inhibitor, suppresses the growth of human colon adenocarcinoma (COLO-320DM) tumors in vivo (Proc Am Assoc Cancer Res 39: 2059, 1998). In this report, we tested the hypothesis that the growth inhibition of these tumors is associated with maintaining minimum effective plasma concentrations of AG3340. Nude mice were given a total oral daily dose of 25 or 200 mg/kg; 6.25 mg/kg was given four times per day (QID) (25 mg/kg/day), and 100 mg/kg was given in two daily doses (BID) (200 mg/kg/day). Peak plasma concentrations (Cmax) of 83 +/- 43 (mean +/- SD) and 1998 +/- 642 ng/ml were detected 30 min after a single dose with 6.25 mg/kg and 100 mg/kg AG3340, respectively. AUC(0-24 h) values estimated from dosing with 25 and 200 mg/kg/day AG3340 were 672 and 10882 ng*h/ml, respectively. Importantly, both regimen inhibited tumor growth equivalently (74 to 82%). Efficacy was also compared at a total daily dose of 25 mg/kg by giving AG3340: QID (6.25 mg/kg per dose), BID (12.5 mg/kg per dose), and once daily (25 mg/kg per dose). The Cmax of these regimens was 83 +/- 43, 287 +/- 175 and 462 +/- 495 ng/ml, respectively. AG3340 did not inhibit tumor growth with the latter two regimens. The efficacy of 6.25 mg/kg QID (25 mg/kg/day) was superior to the efficacy of 25 mg/kg BID (50 mg/kg/day), substantiating the independence of efficacy from the total daily dose and Cmax. Expectedly, peak to trough fluctuations were significantly smaller with the QID regimen than with BID and QD dosing. After 24 h, the trough was greater than 1 ng/ml with QID dosing but was less than 1 ng/ml after QD and BID dosing. These results suggest that the antitumor efficacy of AG3340 was associated with maintaining minimum effective plasma concentrations of AG3340 and demonstrate that the antitumor efficacy of AG3340 was independent of the total daily dose, peak plasma concentration, and drug exposure in this tumor model.     

Correlation of biliary excretion in sandwich-cultured rat hepatocytes and in vivo in rats.

The relationship between biliary excretion in sandwich-cultured rat hepatocytes and in vivo in rats was examined. The biliary excretion of seven model substrates in 96-h sandwich-cultured rat hepatocytes was determined by differential cumulative uptake of substrate in the monolayers preincubated in standard buffer (intact bile canaliculi) and Ca2+-free buffer (disrupted bile canaliculi). Biliary excretion in vivo was quantitated in bile duct-cannulated rats. The biliary excretion index of model substrates, equivalent to the percentage of retained substrate in the canalicular networks, was consistent with the percentage of the dose excreted in bile from in vivo experiments. The in vitro biliary clearance of inulin, salicylate, methotrexate, [D-pen2,5]enkephalin, and taurocholate, calculated as the ratio of the amount excreted into the bile canalicular networks and the area under the incubation medium concentration-time profile ( approximately 0, approximately 0, 4.1 +/- 1.0, 12.6 +/- 2.2, and 56. 2 +/- 6.0 ml/min/kg, respectively), correlated with their intrinsic in vivo biliary clearance (0.04, 0, 17.3, 34.4, and 116.9 ml/min/kg, respectively; r2 = 0.99). The model compound 264W94 was not excreted in bile either in vivo or in vitro. The glucuronide conjugate of 2169W94, the O-demethylated metabolite of 264W94, was excreted into bile in vitro when 2169W94, but not 264W94, was incubated with the monolayers; 2169W94 glucuronide undergoes extensive biliary excretion after administration of 264W94 or 2169W94 in vivo. Biliary excretion in long-term sandwich-cultured rat hepatocytes correlates with in vivo biliary excretion. The study of biliary excretion of metabolites in the hepatocyte monolayers requires consideration of the status of metabolic activities.     

Genistein treatment protects mice from ionizing radiation injury

The radioprotective and behavioral effects of an acute administration of the isoflavone genistein (4',5,7-trihydroxyflavone) were investigated in adult CD2F1 male mice. Mice were administered a single subcutaneous (s.c.) dose of genistein either 24 h or 1 h before a lethal dose of gamma radiation (9.5-Gy of cobalt-60 at 0.6 Gy min(-1)). Mice received saline, PEG-400 vehicle or genistein at 3.125, 6.25, 12.5, 25, 50, 100, 200, or 400 mg kg(-1) body weight. For mice treated 24 h before irradiation there was a significant increase in 30-day survival for animals receiving genistein doses of 25 to 400 mg kg(-1) (p<0.001). In contrast, the 30-day survival rates of mice treated with genistein 1 h before irradiation were not significantly different from those of the vehicle control group. Additionally, the acute toxicity of genistein was evaluated in non-irradiated male mice administered a single s.c. injection of saline, vehicle, or genistein at 100, 200 or 400 mg kg(-1). At these genistein doses there were no adverse effects, compared with controls, on locomotor activity, grip strength, motor coordination, body weight, testes weight, or histopathology. These results demonstrate that a single s.c. administration of the flavonoid genistein at non-toxic doses provides protection against acute radiation injury.     

The biliary and urinary metabolites of [3H]17 alpha-ethynylestradiol in women

The metabolism of 17 alpha-ethynyl[6,7-3H]estradiol (3H-EE2) (50 micrograms) given orally was studied in two groups of women: (a) six subjects from whom duodenal bile samples were obtained after 4 h by endoscopic aspiration; (b) two subjects with bile-duct (T-tube) drainage. The first group eliminated 16.6 +/- 7.8% (mean +/- S.D.) of the dose in urine over 72 h, the second group 28.6% and 27.5%. Biliary excretion by the latter was 41.9% and 28.3% of the dose, respectively, during the first 24 h after dosing. The metabolites excreted in bile and urine were largely polar conjugates: 1-12% of the 3H was ether extractable. Approx. 70-90% of urinary and biliary 3H was extractable following beta-glucuronidase-arylsulphohydrolase hydrolysis. Both beta-glucuronides and arylsulphates were excreted. Unchanged 3H-EE2 was the principal 3H-labelled component of the glucuronide and arylsulphate fractions of bile, and it was a major component of urinary fractions. 2-Hydroxy-EE2 and 2-methoxy-EE2 were identified as conjugated biliary metabolites.     

Kinetics and disposition of hexarelin, a peptidic growth hormone secretagogue, in rats.

To document the disposition of hexarelin, a peptidyl growth hormone secretagogue, male Sprague-Dawley rats received a 5-microg/kg bolus i.v. dose or three single s.c. doses of 5, 10, and 50 microg/kg. To assess hexarelin tissue distribution and excretion, rats were given 1 microg/kg of [(3)H]hexarelin (9.4 Ci/mmol). Metabolism of [(3)H]hexarelin was assessed in bile duct-exteriorized rats given 50 microg/kg where radiolabeled hexarelin biliary and urinary excretion was quantified. After its i.v. injection, hexarelin displayed a half-life of 75.9 +/- 9.3 min, a systemic clearance of 7.6 +/- 0.7 ml/min/kg, and a volume of distribution at steady state of 744 +/- 81 ml/kg. After s.c. administration, the area under the curve (477-3826 pmol.min/ml) estimated with increasing doses confirmed the absence of hexarelin accumulation. Clearance/F (12-15 ml/min/kg) and volume of distribution/F (1208-1222 ml/kg) were dose independent. Hexarelin bioavailability given s.c. was 64%. The highest radioactivity levels were detected in the kidney, liver, and duodenum. The pattern of hexarelin excretion was similar after i.v. or s.c. administrations. Total radioactivity in bile, urine, and feces corresponded to 60, 22, and 10% of the dose, respectively. Of the radioactivity excreted in bile and urine, 90 and 71% was unchanged hexarelin, respectively. These results suggest that: 1) the kinetics of hexarelin appear to be first order up to 50 microg/kg; 2) hexarelin is rapidly absorbed after s.c. administration; 3) biliary excretion is the primary route of hexarelin elimination; and 4) the high recovery of unchanged peptide in bile and urine demonstrates hexarelin stability toward proteolytic enzymes.