Bioavailability,tissue distribution,and excretion characteristics of the novel carbonic anhydrase inhibitor tolsultazolamide in rats

Aim： Tolsultazolamide, a novel carbonic anhydrase inhibitor, is designed for the prophylaxis and treatment of acute mountain sickness. The aim of this study was to investigate the pharmacokinetics, tissue distribution, and excretion characteristics of tolsultazolamide and the sex difference in pharmacokinetics in rats. Methods： For pharmacokinetic study, rats were intravenously injected tolsultazolamide at I and 2 mg/kg or orally administered tol- sultazolamide at 20, 40, or 80 mp=/kg） in a pharmacokinetic study. The concentrations of tolsultazolamide in plasma were determined with high-performance liquid chromatography, with a liquid-liquid extraction. For tissue distribution study, tolsultazolamide （80 mpJkg） was orally administered to overnight fasted rats （six per group and three per sex）. Samples were collected from the brain, heart, lung, liver, spleen, muscle, kidney, stomach, fat, intestines, pancreas and sexual gland. For excretion study, tolsultazolamide （40 mg/kg） was orally administered to 6 rats （three per sex）. The urine, feces, and bile samples were collected at 24, 48, and72 h. Results： After its intravenous administration, tolsultazolamide was rapidly eliminated from the plasma, with T~/2 of about 60-90 min. The AUCo_t and the initial concentration （CO） values were proportional to the intravenous doses. After its oral administration, tolsult- azolamide showed dose-independent pharmacokinetic characteristics, with Tmax and T~/2 of approximately 2 h and 5-7 h, respectively, and good oral absolute bioavailability of about 60%. Tolsultazolamide was distributed widely in various tissues. The highest tolsult- azolamide levels were detected in the stomach, intestine, spleen, lung, and kidney. Total excretion of unchanged tolsultazolamide in the urine, feces, and bile was less than 2%. The Cm,x and AUC of tolsultazolamide were significantly higher in female rats than those in male rats. Clearance and volume of distribution were greater in male rats than those in female rats. The oral absolute bioavailability was also significantly different between female rats （about 83%） and male rats （about 37%）. Conclusion： Tolsultazolamide was well absorbed and widely distributed in the rat, and very little of the unchanged form was excreted. Sex had a significant effect on the pharmacokinetics of tolsultazolamide.     

小剂量丹墨胶囊对大鼠组织中11β-羟基类固醇脱氢酶基因表达的影响

目的考察低剂量丹墨胶囊对11β-羟基类固醇脱氢酶（11β-HSD）基因表达的影响．分析丹墨胶囊与糖皮质激素相互作用的具体机制。方法雄性SD大鼠连续14d灌胃给予丹墨胶囊0．216g／kg后,定量RT-PCR法测定大鼠肝、肾、胸腺、脾、脂肪、肌肉、心脏、肺、小肠、睾丸等组织11β—HSDl、11β-HSD2基因表达。结果丹墨胶囊显著诱导肝脏组织11β-HSDl基因表达,显著抑制大鼠心脏、肺、脾、肌肉、胸腺组织11β-HSDl的基因表达,但对肾脏、脂肪、睾丸、脑、小肠组织的11β-HSDl基因表达无明显影响;抑制心脏、脾、肌肉组织11β-HSD2基因表达,对肝脏、肾、脂肪、睾丸、肺、脑、小肠和胸腺组织的11β-HSD2基因表达无明显影响。结论丹墨胶囊可诱导大鼠肝脏组织中11β-HSDI基因表达,影响糖皮质激素体内活化。     

Azithromycin Cationic Non-Lecithoid Nano/Microparticles Improve Bioavailability and Targeting Efficiency

Purpose

The purpose of this study was to develop and evaluate the azithromycin cationic non-lecithoid nano/microparticles with high bioavailability and lung targeting efficiency.

Methods

The cationic niosomes with different sizes (AMCNS-S and AMCNS-L) along with varied built-in characteristics were produced to achieve high bioavailability and lung targeting efficiency of azithromycin (AM) via two administration routes widely used in clinical practice, i.e., oral and intravenous routes, instead of transdermal route (by which the only marketed niosome-based drug delivery dermatologic products were given). The possible explanations for improved bioavailability and lung targeting efficacy were put forward here.

Results

AMCNS-S (or AMCNS-L) had high bioavailability, for example, the oral (or intravenous) relative bioavailability of AMCNS-S (or AMCNS-L) to free AM increased to 273.19% (or 163.50%). After intravenous administration, AMCNS-S (or AMCNS-L) had obvious lung targeting efficiency, for example, the lung AM concentration of AMCNS-S (or AMCNS-L) increased 16 (or 28) times that of free AM at 12 h; the AM concentration of AMCNS-S (or AMCNS-L) in lung was higher than that in heart and kidney all the time.

Conclusions

The development of niosome-based AM nanocarriers provides valuable tactics in antibacterial therapy and in non-lecithoid niosomal application.     

Pharmacokinetics and tissue distribution of a water-soluble flavonol triglycoside, CTN986, in mice

The pharmacokinetics and bioavailability of CTN986, a highly water-soluble flavonol triglycoside that has shown interesting antidepressant effects, were determined in mice after intravenous ( I. V.), intraperitoneal ( I. P.) and oral administrations. Concentrations of CTN986 in the biological samples were determined by a validated LC/MS/MS method. Non-compartmental methods were used to perform pharmacokinetic data analysis. The dose-dependent pharmacokinetics of CTN986 was characterized after I. V. administrations (0.16, 0.4 and 1.0 mg/kg) to mice. There was no significant difference in clearance (CL) with increasing dose [252.66 +/- 42.82 mL/h (0.16 mg/kg) versus 241.73 +/- 14.93 mL/h (1.0 mg/kg)] after I. V. administrations. The absolute bioavailability of CTN986 after I. P. and oral administrations was 96.57 % and 1.31 %, respectively. CTN986 was found to distribute widely in the internal organs of mice 10 min after oral dosage, with tissue concentrations in the order of duodenum, stomach, small intestine, kidney, lung, liver, brain, heart and spleen (from the highest to the lowest). In conclusion, CTN986 could be absorbed and extensively distributed into tissues as its intact form in mice.     

Evaluation of the pharmacokinetics,tissue distribution and excretion studies of YMR-65, a tubulin polymerization inhibitor with potential anticancer activity,in rats using UPLC-MS/MS

1. YMR-65, 5-(5-bromo-1-methyl-1H-indol-3-yl)-3-(3-methoxyphenyl)-4, 5-dihydro-1H-pyrazole-1-carboxamide, is a new tubulin polymerization inhibitor with encouraging anticancer activity.

2. The validated ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) method was successfully applied to the pharmacokinetics, tissue distribution and excretion study of YMR-65 after oral and intravenous administration. The area under concentration-time curve (AUC_0-∞) for YMR-65 were 151.67?±?54.48 and 459.45?±?49.23?ng/ml*h for oral and intravenous administration at the dosage of 1.5?mg/kg, respectively and the oral bioavailability was about 33.01%. Moreover, YMR-65 was extensively distributed in heart, liver, spleen, lung, kidney, stomach, intestine and testis and the highest were detected in heart, followed by stomach, intestine and liver. The majority of YMR-65 was excreted via feces and its accumulative excretion ratio during the period of 96?h was 19.83?±?3.01%, but only 1.54?±?0.37 and 0.215?±?0.026% for urine within 96?h and bile within 10?h after intravenous administration, respectively, though the fecal and urine excretion were incomplete within 96?h.

3. In summary, this study defined the pharmacokinetic characteristics of YMR-65 in vivo and the important data can be a useful resource for further research and development.     

蒿苯酯在大鼠的药物代谢动力学

大鼠ig蒿苯酯后吸收迅速,其药时曲线出现双峰现象。SPLI非房室模型统计矩计算结果表明,3剂量组平均驻留时间MRT约在12h,半衰期T_1/2约在8h,基本一致。将前8h第一峰血药浓度曲线用3P87程序拟合,药代动力学模型为一室模型。大鼠ig蒿苯酯后2h药物可广泛分布于各组织,6h后各组织中药物浓度均很低。ig蒿苯酯后主要经尿排出,48h经粪尿累积排出70.4%。蒿苯酯平均血浆蛋白结合率约为70%。提取物形式的鉴别结果表明,大鼠ig蒿苯酯后血中以蒿苯酯原型药为主,尿中蒿苯酯及还原青蒿素均有,粪中则以还原青蒿素为主。     

Pharmacokinetics of phenobarbital and propylhexedrine after administration of barbexaclone in the mouse

The antiepileptic barbexaclone is the salt of the base propylhexedrine (indirect sympathomimetic) and phenylethylbituric acid. After i.v. and oral administration of 66 mg/kg barbexaclone to mice the time course of propylhexedrine and phenobarbital concentrations was studied in plasma, brain, lung, liver, kidney, spleen, heart, and skeletal muscle. Furthermore, the kinetics of phenobarbital were studied after treatment with an equimolar dose of phenobarbital-Na (40 mg/kg). In contrast to the i.v. bolus of phenobarbital-Na, barbexaclone was non-lethal only when infused over a period of 3 min. After the i.v. administration of either salt, phenobarbital plasma levels declined monoexponentially with a half-life of 7.5 h; the volume of distribution was 0.78 l/kg. After oral application absorption of phenobarbital was complete with both salts, though it was delayed after barbexaclone. The latter was the result of a delayed gastro-intestinal passage. Brain uptake of phenobarbital was a slow process, equilibrium with plasma concentrations being reached only 30 min after injection. Propylhexedrine reduced phenobarbital concentrations in brain as evident from steady state tissue-plasma ratios. This was observed after i.v. as well as after oral application. After i.v. application of barbexaclone the following pharmacokinetic parameters for propylhexedrine were determined: t0.5 alpha 0.31 h, t0.5 beta 2.5 h, Vd beta 19.3 l/kg; bioavailability (AUC oral/AUC i.v.) 0.37. Propylhexedrine penetrated the blood-brain barrier rapidly. High but unequal tissue accumulation was observed: lung = kidney greater than liver = brain greater than spleen greater than heart greater than skeletal muscle.     

Pharmacokinetics, tissue distribution, metabolism, and excretion of depside salts from Salvia miltiorrhiza in rats.

Salviae miltiorrhiza, a traditional Chinese medical herb known as "Danshen," has been widely used in clinics to improve blood circulation, relieve blood stasis, and treat coronary heart disease. Depside salts from S. miltiorrhiza are a novel drug in which magnesium lithospermate B and its analogs are the active components. The pharmacokinetics, tissue distribution, metabolism, and excretion of three of the major components, lithospermic acid B, rosmarinic acid (RA), and lithospermic acid (LA), were studied by liquid chromatography-tandem mass spectrometry following intravenous administration in Sprague-Dawley rats. The elimination half-lives for LSB, RA, and LA were 1.04, 0.75, and 2.0 h, respectively, when 60 mg/kg S. miltiorrhiza depside salts were administrated. The areas under the curve for LSB, RA, and LA were 51.6, 6.6, and 25.2 mg . h/l, respectively, and the values decreased in the individual tissues in the following order: kidney > lung > liver > heart > spleen > brain for LSB; kidney > lung > heart > liver > spleen > brain for RA; and heart > lung > kidney > liver > spleen > brain for LA. After intravenous administration of 60 mg/kg S. miltiorrhiza depside salts, 86% of the LSB was excreted in the bile within 6 h. The main metabolites M1 and M2 were found in the serum. Overall, the results show that depside salts from S. miltiorrhiza are rapidly and widely distributed to tissues after intravenous administration in rats but that they are also rapidly cleared and excreted.     

Pharmacokinetics,tissue distribution and excretion of coumarin components from <Emphasis Type="Italic">Psoralea corylifolia</Emphasis> L. in rats

Coumarin components from Psoralea corylifolia L. are novel drugs in which psoralen and isopsoralen are the active components. The pharmacokinetics, tissue distribution and excretion of the two compounds were studied by liquid chromatography-tandem mass spectrometry after intravenous administration to Wistar rats. The elimination half-lives of psoralen and isopsoralen were 4.88 and 5.35 h. After dosing, the area under the curves of the tissues decreased in the following order: liver > lung > heart > kidney > spleen > brain for psoralen; and kidney > lung > liver > heart > spleen > brain for isopsoralen. After dosing, 51.27% of psoralen and 56.25% of isopsoralen were excreted as prototype, and urine was the major excretion route. In addition, the pharmacokinetics of psoralen and isopsoralen after oral administration to Wistar rats were also studied. The elimination half-lives of psoralen and isopsoralen were 4.13 and 5.56 h, and their relative bioavailabilities were 61.45% and 70.35%. Overall, the results show that coumarin components from P. corylifolia L. have high oral bioavailability, they are rapidly and widely distributed into tissues after intravenous administration, but they are slowly cleared and excreted.     

Pharmacokinetics and Tissue Disposition of Lenalidomide in Mice

Lenalidomide is a synthetic derivative of thalidomide exhibiting multiple immunomodulatory activities beneficial in the treatment of several hematological malignancies. Murine pharmacokinetic characterization necessary for translational and further preclinical investigations has not been published. Studies herein define mouse plasma pharmacokinetics and tissue distribution after intravenous (IV) bolus administration and bioavailability after oral and intraperitoneal delivery. Range finding studies used lenalidomide concentrations up to 15 mg/kg IV, 22.5 mg/kg intraperitoneal injections (IP), and 45 mg/kg oral gavage (PO). Pharmacokinetic studies evaluated doses of 0.5, 1.5, 5, and 10 mg/kg IV and 0.5 and 10 mg/kg doses for IP and oral routes. Liquid chromatography–tandem mass spectrometry was used to quantify lenalidomide in plasma, brain, lung, liver, heart, kidney, spleen, and muscle. Pharmacokinetic parameters were estimated using noncompartmental and compartmental methods. Doses of 15 mg/kg IV, 22.5 mg/kg IP, and 45 mg/kg PO lenalidomide caused no observable toxicity up to 24 h postdose. We observed dose-dependent kinetics over the evaluated dosing range. Administration of 0.5 and 10 mg/kg resulted in systemic bioavailability ranges of 90–105% and 60–75% via IP and oral routes, respectively. Lenalidomide was detectable in the brain only after IV dosing of 5 and 10 mg/kg. Dose-dependent distribution was also observed in some tissues. High oral bioavailability of lenalidomide in mice is consistent with oral bioavailability in humans. Atypical lenalidomide tissue distribution was observed in spleen and brain. The observed dose-dependent pharmacokinetics should be taken into consideration in translational and preclinical mouse studies.     

Pharmacokinetics,bioavailability and tissue distribution of geniposide following intravenous and peroral administration to rats

In order to characterize the pharmacokinetics, bioavailability and tissue distribution of geniposide following intravenous and peroral administration to rats, a reliable gradient HPLC‐based method has been developed and validated. After p.o. administration of geniposide, the peak concentration of geniposide in plasma occurred at 1 h and plasma geniposide was eliminated nearly completely within 12 h. The AUC_{0→ ∞} values of geniposide were 6.99 ± 1.27 h · µg/ml and 6.76 ± 1.23 h · µg/ml after i.v. administration of 10 mg/kg and p.o. administration of 100 mg/kg of geniposide, respectively. The absolute oral bioavailability (%F) of geniposide was calculated as 9.67%. After p.o. administration of geniposide, the AUC_0→4h values in tissues were in the order of kidney > spleen > liver > heart > lung > brain. This study improved the understanding of the pharmacokinetics, bioavailability and tissue distribution of geniposide in rats and may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines. Copyright © 2013 John Wiley & Sons, Ltd.     

Pharmacodynamics and pharmacokinetics of SQ109, a new diamine-based antitubercular drug

SQ109 is a novel [1,2]-diamine-based ethambutol (EMB) analog developed from high-throughput combinatorial screening. The present study aimed at characterizing its pharmacodynamics and pharmacokinetics. The antimicrobial activity of SQ109 was confirmed in vitro (Mycobacterium tuberculosis-infected murine macrophages) and in vivo (M. tuberculosis-infected C57BL/6 mice) and compared to isoniazid (INH) and EMB. SQ109 showed potency and efficacy in inhibiting intracellular M. tuberculosis that was similar to INH, but superior to EMB. In vivo oral administration of SQ109 (0.1-25 mg kg(-1) day(-1)) to the mice for 28 days resulted in dose-dependent reductions of mycobacterial load in both spleen and lung comparable to that of EMB administered at 100 mg kg(-1) day(-1), but was less potent than INH at 25 mg kg(-1) day(-1). Monitoring of SQ109 levels in mouse tissues on days 1, 14 and 28 following 28-day oral administration (10 mg kg(-1) day(-1)) revealed that lungs and spleen contained the highest concentration of SQ109, at least 10 times above its MIC. Pharmacokinetic profiles of SQ109 in mice following a single administration showed its C(max) as 1038 (intravenous (i.v.)) and 135 ng ml(-1) (p.o.), with an oral T(max) of 0.31 h. The elimination t(1/2) of SQ109 was 3.5 (i.v.) and 5.2 h (p.o.). The oral bioavailability was 4%. However, SQ109 displayed a large volume of distribution into various tissues. The highest concentration of SQ109 was present in lung (>MIC), which was at least 120-fold (p.o.) and 180-fold (i.v.) higher than that in plasma. The next ranked tissues were spleen and kidney. SQ109 levels in most tissues after a single administration were significantly higher than that in blood. High tissue concentrations of SQ109 persisted for the observation period (10 h).This study demonstrated that SQ109 displays promising in vitro and in vivo antitubercular activity with favorable targeted tissue distribution properties.     

盐酸二甲双胍在小鼠体内的药动学和组织分布

目的:研究盐酸二甲双胍在小鼠体内的药动学和组织分布。方法:小鼠灌胃给予盐酸二甲双胍200mg·kg-1,并在给药后0、0.33、0.67、1、2、3、4、6、8、10h共10个时间点采集血样和小肠、肾、肝、胃、肌肉、肺、脾、心脏组织样品(每个时间点小鼠3只),采用高效液相色谱法测定并计算血浆和各组织样品中二甲双胍的浓度。用DAS2.0软件计算药动学参数。结果:盐酸二甲双胍在小鼠体内的血药浓度-时间曲线符合二室模型;主要药动学参数AUC为(52.93±2.34)mg·h·L-1,CL为(0.059±0.002)L·h-1,t1/2为(3.61±0.22)h,tmax为0.67h,Cmax为(18.61±0.78)mg·L-1。在给药后0.67h,所有的组织中都能检测到二甲双胍;给药后10h,心、肝、脾、肺中已检测不到二甲双胍。各组织的AUC值从大到小排列依次为小肠、肾、胃、肝、肌肉、肺、心、脾。结论:盐酸二甲双胍进入小鼠体内后吸收及清除都较迅速,且在小鼠体内分布广泛,但在各组织分布情况显著不同。     

Irreversible protein binding of 14C-imipramine in rats in vivo

Forty-eight hours after a single dose of ¹⁴C-imipramine to rats, ¹⁴C-radioactivity could be measured in the following organs: liver > kidney > serum > fat > spleen > duodenum > lung > muscle and brain. Liver microsomes contained the main part of radioactivity derived from ¹⁴C-imipramine.After exhaustive extraction, only the proteins of liver, kidney, spleen, lung and serum contained measurable amounts of radioactive labeling. The greatest amount of ¹⁴C-imipramine irreversibly bound to proteins was detected in liver microsomes.The question, as to whether the irreversible protein binding of imipramine, if it occurs during therapy, results in toxic side-effects, is discussed.     

葡萄内酯在小鼠体内的组织分布

目的:考察灌胃给药后葡萄内酯在小鼠体内各个组织中的分布情况。方法:给药后,于不同时间点取心、肝、脾、肺、肾、脑、胃、肠、肌肉、脂肪10个组织,制成组织匀浆,用乙酸乙酯萃取富集,氮吹处理后甲醇定容,采用高效液相色谱法测定并计算各个组织中葡萄内酯的浓度。结果:给药后30 min各组织中药物浓度由高到低依次为:胃>肠>肝脏>脂肪>肾>心脏>肌肉>肺>脾>脑;给药后120 min心、肝、脾、肾、脑等组织中出现分布高峰;480 min后依次消除。结论:葡萄内酯能被迅速吸收并广泛分布到各个组织,但吸收消化的过程比较持久,能透过血脑屏障,在靶器官中的作用时间>8 h。     

Pharmacokinetic behavior of gentiopicroside from decoction of radix gentianae,gentiana macrophylla after oral administration in rats: A pharmacokinetic comaprison with gentiopicroside after oral and intravenous administration alone

The pharmacokinetics in rats of gentiopicroside (GPS) from orally administered decoctions of Radix Gentianae (DRG) and Gentiana macrophlla (DGM) were compared with that of GPS alone administered at 150 mg/kg orally and 30 mg/kg intravenously. The metabolic profile of GPS after intravenous injection could be fitted to two-compartment model whereas oral administration decoctions DRG or DGM, or GPS alone, could all be fitted to a one-compartment model. After oral administration of GPS alone, GPS was absorbed quickly and reached a maximum plasma concentration (Cmax) value, 5.78 +/- 2.24 microg/mL within 0.75 +/- 0.62 h. The plasma level of GPS declined with a T1/2ke, 3.35 +/- 0.76 h. After oral administration of decoctions DRG and DGM, GPS was absorbed and reached significantly higher maximum concentrations of 10.53 +/- 3.20 microg/mL (p < 0.01) and 7.43 +/- 1.64 microg/mL (p < 0.05) at later time points 1.60 +/- 0.76 (p < 0.01) and 2.08 +/- 0.74 h (p < 0.05), for DRG and DGM respectively, compared with oral GPS alone. Significantly larger AUC values were found for decoctions of GPS (83.49 +/- 20.8 microgxh/mL for DRG and 59.43 +/- 12.9 microgxh/mL for DGM) compared with oral GPS alone (32.67 +/- 12.9 microgxh/mL). The results demonstrate that the bioavailability of GPS was markedly improved when administered as a decoction than as purified GPS. The decoction from Radix Gentianae provided 2.5 times better bioavailability and that from Gentiana macrophlla 1.8 times higher. The study confirms the importance of careful pharmacokinetic analysis in the characterization of herbal medicines when applied for future clinical applications.     

甘糖酯在小鼠体内的药代动力学研究

用同位素标记法研究了[~3H]甘糖酯1次灌胃后在小鼠体内的药代动力学,其血药浓度——时间曲线符合一室开放模型。小鼠灌服[~3H]甘糖酯25mg/kg(4.48MB_q/kg)后的药动学参数为:t_(1/2)Ka 0.24h;t_(1/2)β67h,V_d921mL,Cl9.58ml/h,AUC41.45mg/(mL·h),F79.3％,PPB54.9％。该药广泛分布于肝、肾、脾、胸腺、肾上腺、肺、心、肌肉和脑内。主要经尿道与粪便排泄。     

玳玳果黄酮降脂提取物体内组织分布规律及特征研究

目的：建立UPLC-MS/MS分析方法同时测定玳玳果黄酮降脂提取物效应组分新橙皮苷和柚皮苷在大鼠10种脏器组织中含量，分布规律及特征。方法：采用UPLC-MS/MS技术建立提取物效应组分新橙皮苷及柚皮苷在大鼠心、肝、脾、肺、肾、脑、胃、小肠、脂质、肌肉组织中的定量分析方法；大鼠给药后分别于0.33，0.67，1，4，8 h的5个时间点，分别摘取以上10种脏器组织，测定脏器组织及血液中效应组分的质量浓度，采用DAS（V 2.0）药动学软件对各样本的药物浓度-时间数据进行房室拟合，并计算不同组织效应组分的药-时曲线下面积（AUC）及平均滞留时间（MRT）。结果：所建立的UPLC-MS/MS定量分析方法具备良好的专属性、标准曲线及线性范围良好、方法准确度与精密度、定量下限均符合有关规定；玳玳果黄酮降脂提取物效应组分在血液中的分布符合一室模型，除肾脏及脑组织外，其余脏器中提取物效应组分的房室特征多为静脉注射的二室模型，柚皮苷在肾脏中的拟合结果为非静脉注射的二室模型，新橙皮苷在脑组织拟合结果为静脉注射的三室模型，给药后8 h各组织中效应组分新橙皮苷及柚皮苷AUC值大小顺序均为小肠 > 胃 > 肾 > 脂质 ≈ 脾脏 > 肺 > 肌肉 > 肝 > 心 > 脑，效应组分在各脏器中均无明显蓄积；效应组分在血液、肾脏、肝脏中的滞留时间较长，MRT均大于2 h，脂质最短，MRT不足1 h；各脏器中新橙皮苷的药-时曲线下面积约是柚皮苷的3倍，而心、肝、肾中则是3.5，2.1和3.4倍。结论：玳玳果黄酮降脂提取物效应组分在大鼠组织中分布迅速，达峰时间早于血液；效应组分在肠道内消除缓慢，给药8 h后在各脏器中的含量均显著下降且无特异的蓄积部位。研究结果揭示玳玳果黄酮降脂提取物效应组分在大鼠体内的分布特征及规律，为进一步理解玳玳果黄酮降脂提取物在体内的作用靶点及机制奠定了基础。     

Studies on absorption, distribution and excretion of 14C labeled (+-)-7-(3-amino-1-pyrrolidinyl)-6-fluoro-1-(2,4-difluorophenyl)-1,4- dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid p-toluene-sulfonate hydrate (14C-T-3262) in rats and mice

Absorption, distribution and excretion of T-3262 were studied in rats and mice after oral administration of 14C-T-3262. The obtained results are summarized as follows. 1. 14C-T-3262 was absorbed from the upper small intestine such as duodenum in rats. 2. Serum levels of radioactivity in rats reached the highest concentration at 1 hour after an oral administration, then gradually diminished. 3. Urinary excretion was 35% and 42% of the dosed radioactivity in rats and mice, respectively, and fecal excretion was about 65% and 56% of the dosed radioactivity in rats and mice, respectively. 4. Biliary excretion in rats was about 27% of the dosed radioactivity after an oral administration of 14C-T-3262, and a half amount of excreted radioactivity was reabsorbed from the intestine. 5. Radioactivity was distributed the most into the kidney and the liver among all organs other the stomach and the intestine. Radioactivity was widely distributed into other organs such as spleen, adrenal, pancreas, lung, heart and thymus. But the distribution of radioactivity into the brain was little. 6. The distribution of 14C-T-3262 was also studied with whole body autoradiography in normal male mice and pregnant mice. The radioactivity was distributed widely to whole tissues except brain, spinal cord and eye ball. In pregnant mice, radioactivity levels in the fetuses were the same as the blood level of the mother mice. 7. The binding rate of 14C-T-3262 to rats and mice serum proteins was 63-66%. 8. Urinary and fecal excretion patterns of radioactivity in mice after multiple oral administration of 14C-T-3262 for 10 days were similar to those after a single administration. This result suggests that T-3262 did not accumulate in body. 9. After oral administration of 14C-T-3262 to nursing rats, the secreted radioactivity level in the milk was higher than the blood level.     

Tissue distribution and pharmacokinetics of 3H-butylated hydroxyanisole in female mice

Butylated hydroxyanisole (BHA), a commonly used food additive, is a phenolic antioxidant. While metabolism of BHA has been studied in dog, man, rabbit and rat, information on tissue distribution is limited to rat and dog. Time dependent distribution and elimination of 3H-BHA following a single oral dose of 50 mg/kg body weight in female Swiss-Webster mice were investigated. Animals were sacrificed at time intervals up to 168 h after dosing. Levels of 3H were determined by liquid scintillation counting in the following tissues: brain, blood, serum, fat, heart, kidney, liver, lung, skeletal muscle and spleen. In most tissues the decline of BHA (log) was nonlinear with respect to time; a biphasic, post-absorptive aspect was observed. The highest 3H activity was noted in kidney and liver 15 min after dosing. The lowest activity was in fat. In addition, a peak 3H activity was recorded at 3 and 10 h after dosing for the blood and brain, respectively. Distribution of the 3H-BHA in mouse organs is similar to that in rat.