Metabolism of 6-Chloro-5-cyclohexylindane-1-carboxylic Acid (TAI-284), a New Non-steroidal Anti-inflammatory Agent. III. Species Differences in Metabolism

Abstract

1. After oral administration, the plasma concn. of TAI-284 reached a peak at 1 h (t_0·5 of 3·5 h) in mice, at 2 h (t_0·5 5 h) in rabbits and at 24 h (t_0·5 4·5 days) in guinea-pigs.

2. In mice and rabbits the major plasma metabolite was the pharmacologically active III (trans-4′-ol), but in guinea-pigs more than 97% of plasma radioactivity was accounted for by unchanged drug. Fraction II, containing an ulcerogenic metabolite, IIb (cis-3′-ol), was found in rat plasma but was not detected in the other 3 species.

3. In mice and rabbits, elimination of ingested radioactivity was completed in 72 h, while with guinea-pigs half the dose remained unexcreted at this time. In rats and mice, excretion in urine and faeces was almost equal, whereas in guinea-pigs and rabbits, more was excreted in urine than in faeces. The major urinary metabolites were the unidentified V and VI in rats and mice and metabolite III in guinea-pigs and rabbits.

4. Studies using liver homogenates or isolated liver profusion system demonstrated that limited hepatic entry of TAI-284 and lower enzyme activity were responsible for the slower metabolism in guinea-pigs.     

Metabolism of 6-Chloro-5-cyclohexylindan-1-carboxylic Acid (TAI-284), a New Non-steroidal Anti-inflammatory Agent,in Relation to Ulcerogenic Activity

6-Chloro-5-cyclohexylindan-1-carboxylic acid (TAI-284) and its cis-3′-hydroxy metabolite, IIb, produced focal ulcers on the mesenteric side of the distal small intestine of rats. The ulcerogenic activity of TAI-284 was more pronounced in male than in female rats. Pre-treatment of male rats with either phenobarbital or 2-diethylaminoethyl 2,2-diphenylvalerate hydrochloride (SKF 525-A) decreased the development of TAI-284-induced intestinal ulceration.

The comparative resistance of males pre-treated with phenobarbital or SKF 525-A, and of females, to ulceration was related to the plasma level of the ulcerogenic metabolite IIb, but not to that of the parent compound. The rate of formation of metabolite IIb by liver 11 000 g supernatant fractions was slower in males pre-treated with SKF 525-A, and in females, than in non-treated males.

The major biliary metabolite(s), VI, were glucuronic acid esters of TAI-284 and its oxo or hydroxy metabolites. The rate of formation and subsequent biliary excretion of metabolite IIb was much slower in mice and guinea-pigs than in rats; the former two species being much less susceptible to the TAI-284-induced intestinal ulceration than rats. About 70% or more of this metabolite was present as glucuronide in rat and mouse bile, but no significant amount of glucuronide was detected in guinea-pig bile.

These findings strongly suggest that metabolite IIb plays a more important role than the parent compound in development of intestinal ulcer in rats, and also that the species variation in ulceration was due, at least partly, to formation of this metabolite in the body.     

Metabolism of 6-Chloro-5-cyclohexylindane-1-carboxylic Acid (TAI-284), a New Non-steroidal Anti-inflammatory Agent. II. Isolation and Identification of Metabolites in the Perfusate of the Isolated Liver Perfusion in Rats

Abstract

1. Biotransformation of 6-chloro-5-cyclohexylindane-1-carboxylic acid labelled with tritium and deuterium was studied in isolated perfused rat liver. Five metabolites were isolated by column and thin-layer chromatography.

2. The metabolites and their methyl esters were characterized by mass and proton magnetic resonance spectrometry with aid of a shift reagent, tris(dipivalomethanato)europium. The following metabolites were identified : 6-chloro-5-(4′-oxocyclohexyl)indane-1-carboxylic acid(metabolite I),6-chloro-5-(cis-4′-hydroxycyclohexyl)indane-1-carboxylic acid (metabolite IIa), 6-chloro-5-(trans-4′-hydroxycyclohexyl)indane-1-carboxylic acid (metabolite III), 6-chloro-5-(cis-3′-hydroxycyclohexyl)indane-1-carboxylic acid (metabolite IV or IIb). Metabolites IV and IIb are diastereoisomers.

3. The compound was metabolized primarily by hydroxylation producing metabolites IIa (cis-4′-ol), IIb (cis-3′-ol), III (trans-4′-ol) and IV (cis-3′-ol). Metabolites IIa and III seemed to be further metabolized to I (4′-oxo).     

Anti-inflammatory property of 6-chloro-5-cyclohexyl-1-indancarboxylic acid (TAI-284) (author's transl)]

Anti-inflammatory activity and the mode of action of TAI-284 were investigated in animal models and compared with the activities of indomethacin. TAI-28 inhibited the increased vascular permeability in rats and mice which is the primary stage of inflammatory process, but the activity was less than that of indomethacin. The compound was as active as indomethacin in inhibiting acute rat paw edema induced by carrageenin and fracture. Furthermore, in the inhibitory effects on ultraviolet erythema in guinea pigs, durable paw edema induced by mustard and wound healing in rats, TAI-284 showed the same or more potent activity than indomethacin. Therefore, TAI-284 proved to have the same anti-inflammatory activity as indomethacin. TAI-284 protected rabbits from sudden death caused by intravenous injection of arachidonic acid, but the activity was about one twentieth less than that of indomethacin. The anti-inflammatory action of TAI-284 was derived from the mode of action of non-steroidal anti-inflammatory drugs, judging from the effects on ultraviolet erythema and death by arachidonic acid. On the other hand, the compound was more potent on secondary or thema and death by arachidonic acid. On the other hand, the compound was more potent on secondary or late stage than on primary stage of inflammation, and to some extent showed the mode of action seen with steroid antiinflammatory drugs. TAI-284 displayed marked inhibitory activity on nystatin induced paw edema in rats. It is suggested that the antinflammatory action of TAI-284 may be due to the lysosomal stabilizing effect.     

抗孕唑(DL111-IT)在大鼠体内的吸收、分布和排泄

大鼠im抗孕唑很快被吸收并分布到各组织中,其中以子宫、卵巢含量最高,其次为肺、心、肾、肌肉,脑、骨中含量较少。大鼠iV抗孕唑后24h,从粪、尿中排出原形药量为0.084±0.039％,168h排出0.396±0.071％。12h内从胆汁排泄的原形药量占给药剂量的1.62±2.04％。可见原药进入体内后很快被代谢。im抗孕唑后1h,注射部位肌肉中的余留量约为给药剂量的50％。t_(1/2)(Ke)=228.812±96.112(min)。     

Metabolic disposition of 6-chloro-5-cyclohexyl-1-indancarboxylic acid (TAI-284), a new non-steroidal anti-inflammatory agent, in rhesus monkeys.

1. After oral administration of 6-chloro-5-cyclohexyl-1-indan[14C]carboxylic acid (TAI-284) to rhesus monkeys, the plasma concn. reached a plateau at 2 h, which persisted for 4 h and then declined with an approximate half-life of 24 h. More than 92% of the plasma radioactivity was derived from unchanged TAI-284. The plasma concn. of the ulcerogenic metabolite, 6-chloro-5-(cis-3'-hydroxycyclohexyl)-1-indancarboxylic acid (metabolite IIb), was much lower in monkeys than in rats. 2. In monkeys, elimination of the ingested radioactivity was complete in 96 h, the excretion being almost equally divided between urine and faeces. This excretory pattern was similar to that in rats. The major urinary metabolites in monkeys were TAI-284, 6-chloro-5-(trans-4'-hydroxycyclohexyl)-1-indancarboxylic acid (metablite III) and glucuronides of TAI-284 and its oxo or hydroxy derivatives (metabolite VI), whereas those in rats were dihydroxy derivatives of TAI-284 (metabolite V) and VI. Unchanged TAI-284 accounted for only a small part of the faecal radioactivity in monkeys and rats. 3. Both in monkeys and rats, some of the dose of radioactivity was excreted in bile to enter into entero-hepatic cycling. Biliary excretion of metabolite IIb was markedly smaller in monkeys than in rats. 4. These metabolic findings are discussed in relation to the variation in the TAI-284-induced intestinal ulceration between monkeys and rats.     

Metabolism of a New Radioprotector; S-Acetyl-N-Glycyl Cysteamine. I. Absorption,Distribution and Excretion Metabolites in Mice Bearing Emt6 Tumours

1.The disposition of S-acetyl-N-glycyl cysteamine (I) labelled with ¹⁴C on the cysteamine group (label 1), the glycyl group (label 2) and the acetyl group (label 3) has been studied in mice bearing EMT6 tumours.

2.Label 1 was mainly excreted in urine (63.1% dose in 24 h). Label 2 elimination was both in urine (36.0% dose in 24h) and in expired air as ¹⁴CO₂ (12.1% dose in 24 h). Label 3 was essentially eliminated in expired air as ¹⁴CO₂ (55.4% dose in 24 h).

3.Tissue distribution studies of label 1 and label 2 showed that concentrations in tissues were higher than blood concentration as early as 10min after administration. Whichever label was used, only little radio-activity was found in EMT6 tumour and brain.

4.Analysis of the urinary elimination products showed the presence of unchanged I and of cystamine, N-acetylcystamine, N-acetyl-S-methyl cysteamine sulphoxide and taurine. I is a prodrug of cysteamine which is released after deacetylation and hydrolysis of the amide bond. A metabolic pathway is proposed for this new radioprotective agent.     

Studies on the Metabolism of d-Limonene (p-Mentha-1,8-diene): I. The Absorption,Distribution and Excretion of d-Limonene in Rats

Abstract

1. The absorption, distribution and excretion of d-limonene were investigated in rats using the ¹⁴C-labelled compound.

2. The highest concentration of radioactivity in blood was obtained 2 h after oral administration of [¹⁴C]d-limonene and most occurred in the serum fraction. Radioactivity in the tissues reached maximum 1 or 2 h after administration. Radioactivity in liver, kidney and blood was higher than in other tissues, but was negligible 48 h after administration. An autoradiographic study confirmed these findings of tissue distribution.

3. About 60% of administered radioactivity was recovered from urine, 5% from faeces and 2% from expired CO₂ within 48 h. In bile duct cannulated rats, about 25% of the dose was excreted in bile within 24 h.     

Metabolism in Rats and Man of Piromidic Acid,a New Antibacterial Agent

1. Metabolism of the antibacterial, piromidic acid (5,8-dihydro-8-ethyl-5-oxo-2-pyrrolidinopyrido[2,3-d]pyrimidine-6-carboxylic acid) was investigated in rats and human subjects. Ten metabolites and the unchanged drug were found in the urine and the bile of both species after oral administration.

2. Metabolites were identified by comparison with authentic materials, except for the unstable metabolite, M-VI, for which a probable structure is proposed. The metabolic pathway of piromidic acid involved hydroxylation in the pyrrolidine ring to give the 2- and 3-hydroxy-derivatives (M-II and M-V). M-II was further metabolized to the corresponding γ-aminobutyric acid derivative (M-IV) and the 2-5-dihydroxypyrrolidine derivative (M-VI) which was further metabolized to the 2-amino-pyridopyrimidine carboxylic acid (M-III). Piromidic acid, M-V, M-II, M-III and M-IV were partly excreted as respective glucuronides.

3. Metabolites, except glucuronides, exhibited antibacterial activity; M-V and M-II showed greater activity than piromidic acid.

4. The metabolism of piromidic acid is discussed in relation to the physico-chemical properties of the drug and its metabolites.     

Absorption,Excretion and Metabolism of a New Dihydropyridine Diester Cerebral Vasodilator in Rats and Dogs

1. After oral administration of [¹⁴C]dihydropyridine diester, the plasma concn. of radioactivity was similar in rats and dogs, reaching a maximum at 0·5 to 1?h and decreasing with a half life of about 3·5 h. The plasma concn. of unmetabolized drug in dogs was 10 times higher than in rats. Radioactivity in rat tissue was high in liver, kidney and lung after both oral and intravenous administration.

2. In both species, 66–72% of radioactivity was excreted in faeces and 23–29% in urine in 48?h, regardless of the route of administration. Biliary excretion in rats after oral dosage amounted to 65%.

3. Eight metabolites were identified from urine of dogs and rats. They were derived from one or several of the following pathways: I, debenzylation of the N-benzyl-N-methylaminoethyl side chain; II, reduction of the 3-nitro group on the phenyl substituent; III, oxidation of the 1,4-dihydropyridine ring to the corresponding pyridine; IV, oxidative removal of the N-benzyl-N-methylamino group yielding a carboxylic acid; V, hydrolysis of the N-benzyl-N-methylamino-ethyl ester to the corresponding carboxylic acid; VI, hydroxylation of the 2-methyl group of the 1,4-dihydropyridine ring to hydroxymethyl.     

Absorption,Distribution, Metabolism,and Excretion of N-Octylbicycloheptene Dicarboximide (MGK 264) Administered Orally to Rats

Abstract

Experiments were conducted in four groups of rats to determine the absorption, distribution, metabolism, and excretion (ADME) patterns following oral administration of [hexyl-1-¹⁴C] N-octylbicycloheptene dicarboximide (MGK 264).

Ten rats (five males and five females) were used in each of the four experiments. Fasted rats were administered fhexyl-1-¹⁴C] MGK 264 at a single oral dose of 100 mg/kg, at a single oral dose of 1000 mg/kg, and at a daily oral dose of 100 mg/kg of nonradiolabeled compound for 14 days followed by a single dose of ¹⁴C-labeled compound at 100 mg/kg. Rat blood kinetics were determined in the fourth group following a single oral dose of 100 mg/kg. Each animal was administered 18-30 μCi radioactivity.

Urine and feces were collected for all groups at predetermined time intervals. Seven days after dose administration, the rats were euthanized and selected tissues and organs were harvested. Samples of urine, feces, and tissues were subsequently analyzed for ¹⁴C content.

In the blood kinetics study, radioactivity peaked at approximately 4 h for the males and 6 h for the females. The decline of radioactivity from blood followed a monophasic elimination pattern. The half-life of blood radioactivity was approximately 8 h for males and 6 h for females.

Female rats excreted 71.45-73.05% of the radioactivity in urine and 20.87-25.28% in feces, whereas male rats excreted 49.49-63.49% of the administered radioactivity in urine and 31.76-46.67% in feces. Total tissue residues of radioactivity at 7 days ranged from 0.13 to 0.43% of the administered dose for all dosage regimens. The only tissues with ¹⁴C residues consistently higher than that of plasma were the liver, stomach, intestines, and carcass. The total mean recovered radioactivity of the administered dose in the studies ranged between 93.1 and 97.4%. No parent compound was detected in the urine.

Four major metabolites and one minor metabolite were isolated from the urine by high-performance liquid chromatography (HPLC) and identified by gas chromatography/mass spectometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS). The four major metabolites were shown to be carboxylic acids produced by either ω-1 oxidation or β-oxidation of the side chain and oxidation of the norbornene ring double bond. The minor metabolite was the carboxylic acid of the intact norbornene ring.

The gender of the animals affected the rate, route of excretion, and metabolic profile. The urinary excretion rate was faster in females than in males and the amount excreted was also greater in female rats.     

Species Differences in Metabolism of Tiaramide Hydrochloride,a New Anti-inflammatory Agent

1. Urinary excretion of the radioactivity in 24?h after oral administration of [¹⁴C]tiaramide hydrochloride was 67% of the dose in mice, 59% in rats, 41% in dogs and 74% in monkeys.

2. The serum half-lives of tiaramide after intravenous administration were approximately 0·2?h in mice, 0·8?h in rats and 0·5?h in dogs.

3. Marked species variations were noted in the composition of metabolites in the serum and urinary radioactivity. The major metabolites found were 1-[(5-chloro-2-oxo-3(2H)-benzothiazolyl)acetyl]-piperazine (DETR) and 4-[(5-chloro-2-oxo-3(2H)-benzothiazolyl)acetyl]-1-piperazineacetic acid (TRAA) in mice, TRAA and 4-[(5-chloro-2-oxo-3(2H)-benzothiazolyl)acetyl]-1-pipera-zineethanol 1-oxide (TRNO) in rats, TRNO and tiaramide-O-glucuronide (TR-O-Glu) in dogs, and TRAA and TR-O-Glu in monkeys.

4. The binding of tiaramide to plasma protein of the various species of animals and human was about 24–34% and the extent of the binding of tiaramide to human plasma protein was independent of drug concentration within the range of 1–100 μM.     

~3H-米酵菌酸在大鼠体内的吸收、分布与排泄

用氚标记物研究了米酵菌酸在大鼠体内的吸收、分布与排出。结果表明,~3H-米酵菌酸经大鼠胃肠道吸收很快,灌胃后15min血浆及主要组织的放射比活性已达高峰,以肝脏为最高。24h内从尿粪排泄的放射性总量为灌胃剂量的70％。胆汁也是一条重要排泄途径,24小时内放射性总排泄量为34％。代谢物从胆汁排泄进入肠道后重新吸入肝,形成肠肝循环,使肝脏反复受到损害。