Thebaine metabolites in the urine of rhesus monkeys

The metabolic fate of thebaine in rhesus monkeys was investigated. Using thin layer chromatography, more than four metabolites were detected in the urine of monkeys given thebaine (8 mg/kg, s.c.). Two of the metabolites isolated by high performance liquid chromatography were not consistent with those reported previously. With the use of gas chromatography-mass spectrometry, the structures were identified as oripavine (3-O-demethylthebaine) and nororipavine (3-O,N-di-demethylthebaine) from the mass spectra of their trimethylsilyl and propionyl derivatives. Further experiments with liver microsomes from rhesus monkeys showed that, in addition to these metabolites, northebaine was also formed from thebaine in the presence of NADPH.

Structural elucidation of a mutagenic metabolite of 3-amino-1-methyl-5H-pyrido[4,3-b]indole

Metabolic activation of a tryptophan pyrolysate, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) by liver microsomes was studied. Trp-P-2 was converted to at least four metabolites (M-1 to M-4), which were separable by HPLC or TLC. Among them, the major metabolite (M-3) was extremely mutagenic to Salmonella typhimurium TA 98 in the absence of activating enzymes and the activity accounted for almost all mutagenic effects of Trp-P-2. Metabolite M-3 was identified as 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole by mass spectrometry and by conversion to the 4-chloro derivative of Trp-P-2 by treatment with hydrochloric acid. The latter compound was identified by NMR and mass spectrometry.

[Radiological study of the accessory skeletal elements in the foot and ankle (author's transl)]

The accessory bones and ossification centers in the foot and ankle were studied in 3,460 radiographs of patients over 7 years of age who consulted our clinic for various reasons from January 1967 to December 1979. The patients comprised of 1,639 males and 1,821 females. The accessory ossicles commonly observed were os tibiale externum, os trigonum, and os peroneum in order of frequency. The os tibiale externum is the commonest accessory bones in the foot and is situated at the point where the tendon of the posterior tibial muscle inserts itself into navicular bone. This ossicle was found to be present in 733 out of 3,460 feet (21.3%). As some authors have pointed out, they are observed somewhat more frequently in females than in males. The os trigonum is an accessory bone which is situated behind the posterior process of the talus. This ossicle was found in 438 feet (12.7%). The os peroneum is a sesamoid in the long peroneal tendon where it bends toward the sole of the foot. This was found in 311 feet (9.0%). Other inconstant skeletal elements were less commonly observed. This os intermetatarseum which is usually located in the first, rarely in the fourth, intermetatarsal space, was found in 91 feet (2.6%). When studied meticulously, this ossicle is found more often than is generally believed. The os subfibulare, situated just under the lateral malleolus, was found in 71 feet (2.1%). The os supranaviculare, situated above the talonavicular joint, was found in 35 feet (1.0%). The os subtibiale, situated just under the medial malleolus, was found in 31 feet (0.9%). The os supratalare, situated above the neck of the talus, was found in 25 feet (0.9%). The calcaneus secundarius, surrounded by calcaneus, talus, os naviculare and os cuboideum, was found in 20 feet (0.6%). The os talotibiale, situated in front of the talocrural joint, was found in 16 feet (0.5%). The os sustentaculi, situated beside the sustentaculum tali, was found in 9 feet (0.3%). The talus accessorius, situated beside the trochlea tali, was found in 6 feet (0.2%). The os vesalianum, situated adjacent to the tuberositas ossis metatarsalis V, was found in 4 feet of the adult patients (0.1%). The talus secundarius, situated near the trochlea peronealis calcanei, was found in 3 feet (0.1%). The os intercuneiforme, located between first and second cuneiform and the navicular bone, was found in only one foot of a 33-year-old male (0.03%). This case may be the first observation in Japan of this extremely rare accessory ossicle. The majority of the patients who had these accessory bones in their feet and ankles seemed to have no clinical complaints. Identification of these ossicles is of importance because they may easily be mistaken as fragments of avulsion fractures. An extra center of ossification for the medical malleolus was observed in 11 feet of the children aged 8 to 11 years. The ossification center for the tuberositas ossis metatarsalis V was found in 56 feet of the adolescents...

Metabolic activation of mutagenic tryptophan pyrolysis products by rat liver microsomes

In an attempt to determine whether cytochrome P-450 metabolizes tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) to active forms, studies were done using microsomes and the 9000 x g supernatant (S-9) from polychlorinated biphenyl mixture-treated rat livers together with Salmonella typhimurium TA 98 as a tester strain. The number of revertants increased with increments in the amount of S-9 fraction added. The highest mutation was seen with an amount of S-9 that is equivalent to 2.5 mg of liver tissue; however, further increase in the S-9 fraction resulted in a sharp decline in the number of revertants. There was a similar biphasic response when a relatively large amount of S-9 fraction was incubated for an increasing length of time. Microsomes showed parallel biphasic responses, and, in addition, the 105,000 x g supernatant fraction was ineffective in increasing the number of revertants. These results suggested that most if not all of the ability of the S-9 fraction to convert Trp-1 and Trp-P-2 to active forms resided in the microsomes. The involvement of microsomal cytochrome P-450 in this process was further confirmed by the following evidence. The treatment of rats with polychlorinated biphenyl mixture and 3-methylcholanthrene resulted in a marked increase in the ability of microsomes to activate Trp-P-1 and Trp-P-2, and the activation reaction required reduced nicotinamide adenine dinucleotide phosphate as a cofactor and was inhibited by carbon monoxide, 7,8-benzoflavone, n-octylamine, and 2-diethylaminoethyl-2,2-diphenylvalerate. The mutagenic metabolite formed as a result of microsomal metabolism of Trp-P-2 was fairly stable and survived heating at 90 degrees for 7 min. With a high-performance liquid chromatography, an active metabolite of Trp-P-2 was purified. A preliminary analysis showed this molecule to be an N-hydroxylated derivative of Trp-P-2.

Metabolic activation of trp-P-2, a mutagenic amine from tryptophan-pyrolysate, by liver microsomes from 3-methylcholanthrene-responsive and non-responsive mice

1. The metabolic activation of a tryptophan pyrolysate, Trp-P-2 (3-amino-1-methyl-5H-pyrido[4,3-]indole), was studied using liver microsomes from mice of 3-methylcholanthrene-responsive, C57BL/6N (B6) strain and non-responsive, DBA/2N (D2) strain. 2. The formation of N-hydroxy-Trp-P-2 (3-hydroxylamino-1-methyl-5H-pyrido-[4,3-b]indole) by hepatic microsomes was markedly increased by the pretreatment with 3-methylcholanthrene in B6 mice, but not in D2 mice. 3. The same treatment increased the activity to convert Trp-P-2 to a mutagen(s) in the Salmonella/microsome test system in B6 mice, but not in D2 mice. 4. The formation of N-hydroxy-Trp-P-2 corresponded with the increase in the number of the revertants, and with the activities of aromatic hydrocarbon hydroxylase and biphenyl 2-hydroxylase. 5. Addition of alpha-naphthoflavone to microsomes from control and 3-methyl-cholanthrene-treated B6 mice effectively decreased the activities to convert Trp-P-2 to a mutagen(s) and to N-hydroxylate Trp-P-2. 6. These results indicate that N-hydroxy-Trp-P-2 is a proximate or ultimate mutagenic principle of Trp-P-2.

Isolation and characterization of active metabolites of tryptophan-pyrolysate mutagen, TRP-P-2, formed by rat liver microsomes

The mutagenic compound derived from the pyrolysis of tryptophan, 3-amino-1-methyl-5H-pyrido-[4,3b]indole (Trp-P-2) was metabolized by rat liver microsomes to more than four metabolites, separable by high performance liquid chromatography. Among these metabolites, two metabolites, M-3 and M-4 were directly active in increasing the frequency of mutation in Salmonella typhimurium TA98. Treatments of rats with polychlorinated biphenyl (PCB) or 3-methylcholanthrene dramatically induced the activity of liver microsomes to form these active metabolites, while treatment with phenobarbital was without effect. A major active metabolite (M-3) formed the pentacyano-ammine ferroate, which is known to be formed by reaction of sodium pentacyano-ammine ferroate with some hydroxylamines. Further this metabolite was oxidized to the minor active metabolite (M-4) with potassium ferricyanide or gamma-manganese dioxide, and was reduced back to Trp-P-2 with titanium trichloride. These results indicated that the major active metabolite of Trp-P-2, which is formed by cytochrome P-450, is the 3-hydroxyamino derivative.

The apparent loss of cytochrome P-450 associated with metabolic activation of carbon tetrachloride

Carbon monoxide inhibited the carbon tetrachloride-induced NADPH oxidation rate. The addition of methylviologen to the incubation mixture under the atmosphere of nitrogen resulted in the enhancement of the reductase activity of microsomes for carbon tetrachloride, as determined by chloroform formation. The addition of methylviologen also enhanced the carbon tetrachloride-induced loss of cytochrome P-450, while the apparent content of cytochrome b5 and the activity of NADPH-cytochrome c reductase remained unchanged. Under a strong inhibition of lipid peroxidation by addition of EDTA, carbon tetrachloride induced a clear loss of cytochrome P-450 to the extent similar to that seen in the absence of EDTA. These results indicate that cytochrome P-450 is directly degraded in association with the reductive metabolism of carbon tetrachloride by cytochrome P-450.