~3H-莪术醇在正常大鼠及肿瘤小鼠体内的代谢研究

~8H-莪术醇自大鼠胃肠道吸收迅速且完全。灌胃后5分钟血中即有放射性,15分钟达高峰,1小时仍保持较高浓度,放射性自血中消失的生物半衰期为11.5小时(t_(1/2)β)。静脉注射后血中放射性的消失分快、慢两相,生物半衰期分别为33分钟(t_(1/2)α)及12.5小时(t_(1/2)β)。 放射性在正常大鼠体内分布情况与肿瘤小鼠者相似。肝及肾组织含量约为其它组织的2～2.5倍。肿瘤组织中的分布与其它组织无明显差别;组织中放射性的消失与血浆中者略呈平行关系。放射性与脂肪组织似有较强的亲和力,给药后4小时仍维持较高水平。 放射性主要自尿排泄,口服或静脉注射后24小时分别自大鼠尿排出剂量的45.38％及51.91％。胆汁为另一排泄途径,大鼠口服或静脉注射后24小时,分别自胆汁排出36.47％及56.43％,而口服或静脉注射后72小时仅从粪回收6.77％及14.35％,可见,自胆汁排出的放射性大部分均又被重吸收入血。     

葛根有效成分的代谢研究——Ⅱ.~(14)C-黄豆甙元在大鼠体内的吸收、分布和消除

本文采用纸片液体闪烁计数法研究了~(14)C-黄豆甙元在大鼠体内的吸收、分布和消除。大鼠口服~(14)C-黄豆甙元30分钟,血液即可测出放射性,6～8小时达高峰,以后缓慢下降。口服给药吸收不完全,由实验推论约有64.6％放射性可被吸收。静脉注射后,血放射性消失曲线分为快、慢两个时相,其生物半衰期分别为13分钟和42分钟。放射性在肾、肝含量最高,血浆、肺、心次之,肌肉、脾、睾丸、脑较低。静脉注射后,~(14)C主要自尿排出(24小时可排出剂量的71.2％),自粪排出17.4％。口服后24小时可自尿排出34.3％,自粪排出33.1％。胆汁也是一条重要排泄途径,静脉注射后24小时可自胆汁排出剂量的47.4％;口服后相应时间内排出39.1％。 本文所得结果与前文应用化学方法所得结果进行比较,表明自消化道、尿、胆汁所回收的放射性主要是黄豆甙元的代谢产物,说明该药在体内的代谢很旺盛。     

二苯乙烯苷在大鼠体内外的代谢研究

采用肝微粒体温孵和大肠杆菌培养等方法对二苯乙烯苷进行体外代谢研究.灌胃给予二苯乙烯苷后,对大鼠血液、胆汁、尿液、粪便、胃和小肠内容物进行体内代谢产物分析,并通过制备液相色谱从胆汁中获得主要代谢物的纯品,采用1HNMR、13CNMR及MS方法进行结构确证.结果表明,二苯乙烯苷在大鼠肝脏代谢为葡萄糖醛酸结合物,并经胆汁排泄,在肠道内菌或酶的作用下水解为二苯乙烯苷随粪便排出.     

氚标记盐酸川丁特罗的合成和大鼠口服后排泄动力学（英文）

目的探讨大鼠口服放射性氚标记盐酸川丁特罗([3H]SPFF)后经尿、粪和胆汁的排泄动力学特征。方法采用化学法合成[3H]SPFF,并进行放化纯度鉴定。粪尿排泄实验观察SD大鼠经口45.5 MBq·kg-1(1 mg·kg-1)给药后168 h内经尿和粪累积放射性排出率。胆汁排泄实验观察胆汁引流模型大鼠给药后,72 h内胆汁累积放射性排出率。HPLC-放射性检测法鉴定单只大鼠尿和胆汁中放射性成分组成。结果化学法合成获得5 m L[3H]SPFF甲醇溶液(比活度403 GBq·g-1),化学纯度>96%,放化纯>97%。粪尿排泄实验的结果表明,经口给药后,SD大鼠体内放射性物质经泌尿系统排出较快,168 h经尿粪累积排出率达84.74%,其中尿回收56.63%,粪回收28.10%。胆汁排泄实验显示,给药后3 d,经胆汁放射性累积排出率为29.3%。放射性组成分析结果显示,单只SD大鼠给药后72 h尿液中累积总放射性排出量占给药量的48.61%,其中原型占4.71%,产物占42.62%。72 h胆汁中累积总放射性排出量占给药量的28.14%,其中原型占9.51%,产物占18.63%。结论大鼠经口盐酸川丁特罗后吸收完全,主要经尿液以代谢物形式排泄。     

一起因食用变质银耳引起的椰毒假单孢菌酵米面亚种食物中毒调查报告

目的了解椰毒假单孢菌酵米面亚种食物中毒流行特征。方法对中毒现场进行流行病学调查、病原学调查和动物实验。结果从可疑银耳中检出椰毒假单孢菌,从52例患者血液中检出椰毒假单孢菌及米酵菌酸,实验小鼠染毒死亡后解剖见肝脏广泛性出血,从其血液中检出此菌和米酵菌酸。结论此次食物中毒是由因食用变质银耳而引起的椰毒假单孢菌酵米面亚种食物中毒。     

抗雄激素新药:Bifluranol 的体内过程

Bifluranol 是氟取代的联苄类抗雄激素药物,化学名为赤型-3,3′-二氟-4,4-二羟基-α-乙基-α′-甲基-联苄,商品名:‘Prostarex’。其抗雄激素作用与己烯雌酚相似,而在大鼠,雌激素样副作用仅为己烯雌酚的1/8。本品毒性低,临床正用于治疗前列腺肥大。给狗、鼬(ferret)和大鼠口服~3H-bifluranol 50、60和200μg/kg,药物很易吸收,胆汁中放射性很高,但血中放射性始终很低。静脉给药后血药浓度2～3小时内迅速下降,4小时内大部分从胆汁排泄。药物主要经粪排出,仅很少量在尿中出现。大鼠剂量的4％(雄性)和0.7％(雌性)的~3H 转变为~3H_2O 在尿中出现,而狗和鼬尿却缺如。大鼠和鼬的呼出气体中可见微量~3H。作者认为,动物给药后吸收良好,并迅速为肝脏摄取,使血药     

三尖杉酯碱的代谢

本文报告~3H-三尖杉酯碱在正常及肿瘤鼠体内的吸收、分布和排泄。静脉注射~3H-三尖杉酯碱后,大鼠血中放射性迅速降低,快、慢两相的生物半衰期分别为3.5分钟和50分钟。给大鼠静脉注射~3H-三尖杉酯硷,注射后15分钟时,药物在各组织中的分布以肾脏为最高,肝、骨髓、肺、心脏、胃肠、脾、肌肉次之,睾丸、血及脑较低。两小时后各组织中的药物浓度均迅速下降,但骨髓的下降较慢,在所有组织中药物浓度居于首位。24小时后则在所测组织中药物浓度均降到相当低的水平。~3H-三尖杉酯碱在肿瘤小鼠体内的分布情况与正常大鼠的分布趋势大致相仿。~3H-三尖杉酯碱在静脉注射后24小时自大鼠体内排出的总放射性,在尿相当于注射剂量的30.2％,在粪相当于16.6％,其中原型药共占14.5％。此外胆汁也是一条重要排泄途径。静脉注射后24小时可自胆汁排出剂量的24.5％,其中原型药占17.1％。该硷口服给药可迅速吸收入血,但吸收不完全。     

9-硝基喜树碱单次灌胃给药后大鼠体内的分布与排泄

目的:建立测定生物样品中9-硝基喜树碱的反相高效液相色谱法,研究其在大鼠体内处置的规律及特点。方法:SD大鼠单次灌胃9-硝基喜树碱3．0 mg·kg~(-1)后摘取组织,收集粪、尿、胆汁,用HPLC方法测定药物浓度,计算累积排泄率。结果:9-硝基喜树碱单次灌胃后在各组织广泛分布,24h内原形药从尿及粪中排泄量24066．3ng,占给药量的1．814%,给药后12h原形药从胆汁中排泄13253．7ng,占给药量的1．62%。结论:9-硝基喜树碱原形药累积排泄率约为3．43%,可能主要以代谢物形式排出体外。     

大鼠体内桃核承气汤蒽醌类药代动力学研究

目的研究桃核承气汤中蒽醌类成分在大鼠体内药代动力学规律。方法大鼠灌胃给予桃核承气汤5、10 g.kg-1后,采集血浆、尿和胆汁,用HPLC方法分析样品中蒽醌类成分、测定血浆中大黄酸浓度经时变化,浓度-时间数据用3P97药代动力学软件进行分析,计算药动学参数。结果大鼠灌胃给予桃核承气汤后,血浆中检测到芦荟大黄素、大黄酸、大黄素,尿中检测到芦荟大黄素、大黄酸、大黄素和大黄酚,胆汁中检测到大黄酸和大黄酚;血液、尿液和胆汁中均以大黄酸含量最高,且经尿排泄的量明显多于经胆汁排泄的量。灌服桃核承气汤5和10 g.kg-1剂量组,T12(α)为0.03和0.13 h,T12(β)为1.46和2.51 h,T12(Ka)为0.01和0.12 h,V1为0.14和0.12 L.kg-1,CL为0.77和0.33 L.h-1.kg-1,Cm ax为(2.15±0.29)和(9.70±2.50)mg.L-1,Tpeak为(0.19±0.04)和(0.23±0.04)h,AUC0-∞为1.69和6.50 mg.L-1.h。结论桃核承气汤中蒽醌类成分可以吸收进入体内,其中以大黄酸为主;体内蒽醌类成分经尿和胆汁排泄,其中以尿排泄为主。大鼠灌服桃核承气汤,血浆中大黄酸浓度时间过程符合二室开放模型。     

3H-莪术醇在正常大鼠及肿瘤小鼠体内的代谢研究

³H-莪术醇自大鼠胃肠道吸收迅速且完全。灌胃后5分钟血中即有放射性,15分钟达高峰,1小时仍保持较高浓度,放射性自血中消失的生物半衰期为11.5小时(t_(1/2)β)。静脉注射后血中放射性的消失分快、慢两相,生物半衰期分别为33分钟(t_(1/2)α)及12.5小时(t_(1/2)β)。放射性在正常大鼠体内分布情况与肿瘤小鼠者相似。肝及肾组织含量约为其它组织的2～2.5倍。肿瘤组织中的分布与其它组织无明显差别;组织中放射性的消失与血浆中者略呈平行关系。放射性与脂肪组织似有较强的亲和力,给药后4小时仍维持较高水平。放射性主要自尿排泄,口服或静脉注射后24小时分别自大鼠尿排出剂量的45.38%及51.91%。胆汁为另一排泄途径,大鼠口服或静脉注射后24小时,分别自胆汁排出36.47%及56.43%,而口服或静脉注射后72小时仅从粪回收6.77%及14.35%,可见,自胆汁排出的放射性大部分均又被重吸收入血。     

Species differences in disposition of benzo[a]pyrene

Comparison of disposition of benzo[a]pyrene (B[a]P) among Sprague-Dawley rats, Gunn rats, hamsters, and guinea pigs was performed. [3H]B[a]P was administered intratracheally to animals, and the rate of excretion of radioactivity into bile, types of metabolites of B[a]P in bile, and distribution of radioactivity among tissues were determined. In Sprague-Dawley rats, Gunn rats, and guinea pigs, the rate of excretion of radioactivity was dependent upon the administered dose. Excretion and tissue distribution of radioactivity were qualitatively similar among these species although quantitative differences were observed. In hamsters, the rate of excretion was essentially independent of dose at the concentrations examined (0.16 and 350 micrograms). The major difference between hamsters and the other species was that increased amounts of radioactivity were retained in lungs of hamsters at the lower dose with a proportional decrease in the amount of radioactivity excreted into bile. The types and relative amounts of conjugated and nonconjugated metabolites of B[a]P were similar in bile of Sprague-Dawley rats and hamsters. Smaller amounts of glucuronides and larger amounts of sulfate conjugates were detected in bile of Gunn rats than in bile of Sprague-Dawley rats or hamsters. Metabolites in bile of guinea pigs were markedly different from those in the other species in that approximately 90% of the metabolites were thioether conjugates. Buthionine sulfoxime was used to reduce tissue levels of glutathione in Sprague-Dawley rats. When liver and lung glutathione levels were reduced to 30% and 82% of control levels, respectively, the amount of radioactivity excreted into bile was not significantly different from controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Disposition of an antineoplastic sesquiterpene lactone, [3H]-plenolin, in BDF1 mice.

The pharmacokinetics of a radiolabelled analog of helenalin, [3H]-plenolin ([3H]-11,13-dihydrohelenalin), was determined in BDF1 mice following intravenous, intraperitoneal, and oral administration. A two-compartment pharmacokinetic model predicted that the maximum terminal (beta) half-life of [3H]-plenolin was 57.3 hours. Urinary excretion accounted for 40.3% to 64.4% of the administered radioactivity, while fecal excretion accounted for 9.3% to 39.7%. The fecal excretion data also suggested that [3H]-plenolin was secreted in the bile. Following intraperitoneal administration of [3H]-plenolin, no radioactivity was sequestered in the major organs. However, radioactivity was sustained in the carcass and skin for 24 days. [3H]-Plenolin was rapidly taken up by murine tumor cells and human fibroblasts. The drug did not significantly associate with DNA, RNA, or protein of P388 leukemia or human fibroblast cells.     

Metabolic fate of the new anti-ulcer drug enprostil in animals. 1st communication: absorption, distribution and excretion in the mouse, rat and rabbit

Absorption, distribution and excretion of [3H]-enprostil ((+-)-11a,15a-dihydroxy-9-oxo-16-phenoxy-17,18,19,20-tetranorpr osta -4,5,13(t)-trienoic acid methyl ester, TA-84135), a new anti-ulcer prostaglandin, were studied in mice, rats and rabbits. Radioactivity associated with enprostil was rapidly absorbed from the gastrointestinal tract with Tmax values of 15 or 30 min. Absorption was also efficient inasmuch as approximately 80% of an oral dose was recovered in bile and urine in 24 h in bile duct-cannulated rats. Experiments in pylorus-ligated, bile duct-cannulated rats demonstrated that enprostil was mainly absorbed from the intestine, rather than from the stomach. In mice given oral doses of 2, 8 and 32 micrograms/kg, Cmax and AUC values of enprostil radioequivalents increased proportionately to the increase in dose, indicating linear kinetics over this dose range. Distribution of enprostil-associated radioactivity was investigated in rats by quantitating tritium in various tissues after the oral administration of [3H]-enprostil. Radioactivity in tissues was highest at 15 or 30 min after dosing. Highest levels of radioactivity were found in the stomach and intestines, the organs which came into direct contact with the dose, and the liver and kidney, the organs involved in excretion of enprostil. The rate of elimination of enprostil-associated radioactivity from all tissues and from plasma was similar. Enprostil-associated radioactivity did not accumulate in any tissue. Radioactivity was found in fetuses following oral administration of [3H]-enprostil to rats on the 12th or 19th day of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metabolism and disposition of 2,3,7,8-tetrachlorodibenzo-p-dioxin in guinea pigs

Marked interspecies variability exists in the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with the guinea pig being the mammalian species most sensitive to the acute toxicity of TCDD. The metabolism and disposition of TCDD was investigated in guinea pigs for 45 days following a single exposure to purified [3H]TCDD (0.56 microgram/kg, ip). Guinea pigs included in the toxicokinetic study gained body weight, maintained a normal relative body composition, and exhibited no gross signs of toxicity during the 45-day study. Approximately 36% of the dose of TCDD-derived 3H remained in the adipose tissue at 45 days following exposure to [3H]TCDD, while the liver, pelt, and skeletal muscle and carcass each contained about 7% of the administered dose. Although most of the TCDD-derived radioactivity in liver, kidney, perirenal adipose tissue, and skeletal muscle represented unchanged TCDD, from 4 to 28% of the 3H was associated with metabolites of TCDD. This unexpected finding suggests that TCDD metabolites are not efficiently excreted from guinea pigs. The urinary and fecal excretion of TCDD-derived radioactivity followed apparent first-order kinetics, with an elimination half-life of 93.7 +/- 15.5 days (mean +/- SD). HPLC analysis of urine and bile from [3H]TCDD-treated guinea pigs showed that all of the radioactivity represented metabolites of TCDD, indicating that these routes of elimination are dependent on prior metabolism of TCDD. However, 70 to 90% of the radioactivity in fecal samples was found to represent unmetabolized TCDD throughout the 45-day excretion study. The presence of TCDD in feces and its absence in bile suggest that the fecal excretion of unchanged TCDD resulted from the direct intestinal elimination of the lipophilic toxin. Furthermore, the cumulative excretion of TCDD-derived radioactivity over 45 days indicated that 74.3% of the 3H was excreted in feces as unchanged TCDD, while 25.7% of the 3H was excreted in urine and feces as TCDD metabolites. Thus, TCDD is primarily eliminated unchanged in the feces of guinea pigs, indicating that the metabolism of TCDD does not play a major role in the ultimate elimination of the toxin from the guinea pig. This may in part explain the relatively long excretion half-life for TCDD in the guinea pig and may contribute to the remarkable sensitivity of the guinea pig to the acute toxicity of TCDD.     

Incidence of experimental ochratoxicosis on hepatic disposition of [3h]tetracycline and chloramphenicol in rats

[³H]Tetracycline or chloramphenicol were injected i.v. into anaesthetized controls and 12-day ochratoxin A-administered rats. The biliary excretion and hepatic levels of [³H]tetracycline were decreased whereas bile flow did not vary and plasma bioavailability of radioactivity increased in comparison with control rats. Ochratoxicosis induced also lower biliary excretion of glucuronide conjugated form of chloramphenicol without any change in its plasma or liver concentration.     

Incidence of experimental fascioliasis on hepatic disposition of [3H]tetracycline and [14C]rafoxanide in rats

[7-3H]Tetracycline and [carbonyl-14C]rafoxanide were injected intravenously into anesthetized controls and rats in which experimental fascioliasis had been induced by 20 Fasciola hepatica metacercariae. The biliary excretion (1 and 3 h, respectively) of the radioactivity consisted of approximately 4% of the administered dose. In 4-week infested rats, biliary excretion of [3H]tetracycline and hepatic levels of radioactivity were decreased, whereas bile flow did not vary and plasma clearance of the antibiotic was significantly decreased in comparison with control animals. These differences could be the result of the fascioliasis-induced decrease in the hepatic uptake of tetracycline and the limited active transport for its output into bile canaliculi. No change in [14C]rafoxanide disposition was shown in infested rats.     

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the distribution and biliary excretion of polychlorinated biphenyls in rats.

Plasma disappearance, biliary excretion, and tissue distribution of two polychlorinated biphenyls (PCBs), 2,5,2′,5′-[³H]tetrachlorobiphenyl (4-CB) and 2,4,5,2′,4′,5′-[³H]hexachlorobiphenyl (6-CB), was determined in rats 10 days after oral administration of a single 10 or 25 μg/kg dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Plasma disappearance of both PCBs was not altered by TCDD treatment, but biliary excretion was depressed. Associated with the depressed excretion was a reduction in bile flow and concentration of 4-CB- and 6-CB-derived ³H in bile. Treatment with TCDD resulted in less PCB being distributed to the skin and a greater percentage of the dose being accumulated in the liver. The content of PCB-derived ³H in skeletal muscle, adipose tissue, and urine was similar in control and TCDD-treated rats. Extraction of bile with hexane showed that the majority of biliary radioactivity was in the form of polar metabolites and that the proportion of parent PCB (hexane-extractable radioactivity) to polar metabolites was not altered by TCDD treatment. In rats given 4-CB and sacrificed 1 hr later, the majority of radioactivity in the liver was hexane extractable, and the smaller amount of hepatic radioactivity due to polar 4-CB metabolites was greater in the TCDD treatment group than in the control group. When biliary metabolites of 4-CB were administered, biliary excretion of the metabolites was depressed in TCDD-treated animals. Thus, TCDD treatment impairs the initial and main excretory pathway for PCB elimination in the rat—biliary excretion—and alters the distribution of PCBs to the skin and liver.     

Pharmacokinetics of the mycotoxin penicillic acid in male mice: absorption, distribution, excretion, and kinetics

The pharmacokinetics of penicillic acid (PA), a carcinogenic mycotoxin, was investigated in male mice. Absorption of PA after po administration of [14C]PA was rapid. Only a small percentage of the radioactivity in the plasma was unchanged PA. After ip or iv administration of [14C]PA (90 mg/kg), blood, liver, kidneys, intestine, lungs, heart, and spleen contained the largest amounts of radioactivity while brain tissue accumulated the least. Over 90% and approximately 60% of the administered radioactivity was excreted in the urine after iv and ip injection, respectively, but essentially no unchanged PA was detected in the urine. Over 25% of the administered radioactivity following an iv dose of [14C]PA (90 mg/kg) was excreted in the bile in 60 min; no unchanged PA was detected in the bile. The excretion of radioactivity in the bile was decreased in diethyl maleate-pretreated mice. Only a small amount of the administered radioactivity was recovered in the feces and as expired CO2. The unchanged PA concentration-time curve in plasma was best fit by three, two, and one compartment open models after iv, ip, and po administration, respectively. Based on these results, it was concluded that metabolism and not excretion of unchanged parent penicillic acid is the major process of elimination of PA from the blood. There are extensive route-dependent differences in the kinetic behavior of PA.     

Urinary and biliary metabolites of mephentermine in male Wistar rats

1. Excretion of urinary and biliary radioactivity, and metabolites of [3H]mephentermine (MP), after i.p. or subcutaneous administration of [3H]MP to male Wistar rats, were determined by preparative t.l.c.-liquid scintillation counting. 2. About 45% of the radioactivity administered i.p. was excreted in the 24 h urine. The major urinary metabolite was conjugated p-hydroxymephentermine (p-hydroxy-MP), which accounted for about 18% of the administered radioactivity in the 24 h urine. 3. About 4.2% of the radioactivity administered subcutaneously was excreted in bile during 24 h. The major biliary metabolite was conjugated p-hydroxy-MP, which accounted for about 39% of the radioactivity excreted in the bile in 24 h. 4. Urinary and biliary minor metabolites detected were phentermine (Ph), p-hydroxyphentermine (p-hydroxy-Ph), N-hydroxyphentermine (N-hydroxy-Ph), N-hydroxymephentermine (N-hydroxy-MP) and their conjugates, and conjugated MP. 5. The conjugates were considered to be glucuronides from the inhibitory effect of saccharic acid 1,4-lactone on their hydrolysis with beta-glucuronidase. 6. Biliary excretion rates of conjugated p-hydroxy-Ph and p-hydroxy-MP reached maxima at 3 to 4 h, and non-conjugated metabolites were maximal at 1 to 2 h, after administration. 50% of the biliary metabolites was excreted within 5 h.     

Effect of pitavastatin on sterol and bile acid excretion in guinea pigs

The influence of pitavastatin (CAS 147526-32-7), a potent 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, exerted on fecal and biliary excretion of sterols and bile acids was investigated using guinea pigs. The cumulative amount of [3H] bile acid in bile 0 to 6 h after the injection of high density lipoprotein (HDL), which was labeled with [3H] cholesteryl ester (CE), was slightly decreased with atorvastatin (30 mg/kg, CAS 134523-00-5) and simvastatin (30 mg/kg, CAS 79902-63-9), and the same level as the control was maintained with pitavastatin (3 mg/kg). The amount of excretion of [3H] sterol into bile was significantly increased with atorvastatin and simvastatin, and exhibited a tendency to decline with pitavastatin. The [3H] bile acid/[3H] sterol ratios were significantly lowered with atorvastatin and simvastatin by 41% and 29%, respectively, as compared to the control, and exhibited an upward tendency with pitavastatin (22%). The total amounts of fecal [3H] bile acid from 0 to 7 days were significantly decreased with atorvastatin and simvastatin by 30% and 32%, respectively, and slightly increased with pitavastatin by 8% Furthermore, mRNA expression of the hepatic microsomal cytochrome P-450 enzyme, cholesterol-NADPH: oxygen oxidoreductase (cholesterol 7 alpha-hydroxylase; CYP7A), which is a late limiting enzyme with a bile acid composition, was also decreased with atorvastatin and simvastatin by 54% and 38%, respectively, and slightly increased with pitavastatin (14%). The change in CYP7A mRNA expression was well correlated with the amount of the fecal [3H] bile acid. The bile acid excreting efficacy of pitavastatin was relatively high as compared with atorvastatin or simvastatin. It is suggested that this action may contribute to the powerful cholesterol lowering action of pitavastatin.