The metabolic fate of amphetamine in man and other species

1. The fate of [(14)C]amphetamine in man, rhesus monkey, greyhound, rat, rabbit, mouse and guinea pig has been studied. 2. In three men receiving orally 5mg each (about 0.07mg/kg), about 90% of the (14)C was excreted in the urine in 3-4 days. About 60-65% of the (14)C was excreted in 1 day, 30% as unchanged drug, 21% as total benzoic acid and 3% as 4-hydroxyamphetamine. 3. In two rhesus monkeys (dose 0.66mg/kg), the metabolites excreted in 24h were similar to those in man except that there was little 4-hydroxyamphetamine. 4. In greyhounds receiving 5mg/kg intraperitoneally the metabolites were similar in amount to those in man. 5. Rabbits receiving 10mg/kg orally differed from all other species. They excreted little unchanged amphetamine (4% of dose) and 4-hydroxyamphetamine (6%). They excreted in 24h mainly benzoic acid (total 25%), an acid-labile precursor of 1-phenylpropan-2-one (benzyl methyl ketone) (22%) and conjugated 1-phenylpropan-2-ol (benzylmethylcarbinol) (7%). 6. Rats receiving 10mg/kg orally also differed from other species. The main metabolite (60% of dose) was conjugated 4-hydroxyamphetamine. Minor metabolites were amphetamine (13%), N-acetylamphetamine (2%), norephedrine (0.3%) and 4-hydroxynorephedrine (0.3%). 7. The guinea pig receiving 5mg/kg excreted only benzoic acid and its conjugates (62%) and amphetamine (22%). 8. The mouse receiving 10mg/kg excreted amphetamine (33%), 4-hydroxyamphetamine (14%) and benzoic acid and its conjugates (31%). 9. Experiments on the precursor of 1-phenylpropan-2-one occurring in rabbit urine suggest that it might be the enol sulphate of the ketone. A very small amount of the ketone (1-3%) was also found in human and greyhound urine after acid hydrolysis.     

The fate of sulphadimethoxine in primates compared with other species

1. The metabolism of sulphadimethoxine (2,4-dimethoxy-6-sulphanilamidopyrimidine) was examined in nine species of primates and nine species of non-primates. 2. The main metabolite of the drug in the urine in man, rhesus monkey, baboon, squirrel monkey, capuchin, bushbaby, slow loris and tree shrew was sulphadimethoxine N(1)-glucuronide. In the green monkey, although the main metabolite was N(4)-acetylsulphadimethoxine, the N(1)-glucuronide was also a major metabolite. 3. In the dog, rat, mouse, guinea pig, Indian fruit bat and hen the N(1)-glucuronide was a minor metabolite in the urine, whereas in the cat, ferret and rabbit this glucuronide was not found in the urine. 4. All the species examined except the dog excreted some N(4)-acetylsulphadimethoxine, which was the major metabolite in the green monkey, rabbit and guinea pig. 5. In the tree shrew, a doubtful primate, N(1)-glucuronide formation was similar to that in the other primates. 6. It is suggested that the slow excretion of the drug by the rat may be due partly to strong binding of the drug to tissue proteins and that the strength of binding may vary with species. 7. In the rat the amount of N(1)-glucuronide found in the urine is not a true indication of the extent of this conjugation since much more of the conjugate was found in the bile (7% of the dose) than in the urine (1%). In the rabbit, no N(1)-glucuronide was found in the bile or urine, but a small amount of sulphadimethoxine N(4)-glucuronide was found in the bile of the rat (0.5% of dose) and rabbit (0.8%).     

The fate of benzoic acid in various species

1. The urinary excretion of orally administered [¹⁴C]benzoic acid in man and 20 other species of animal was examined. 2. At a dose of 50mg/kg, benzoic acid was excreted by the rodents (rat, mouse, guinea pig, golden hamster, steppe lemming and gerbil), the rabbit, the cat and the capuchin monkey almost entirely as hippuric acid (95–100% of 24h excretion). 3. In man at a dose of 1mg/kg and the rhesus monkey at 20mg/kg benzoic acid was excreted entirely as hippuric acid. 4. At 50mg/kg benzoic acid was excreted as hippuric acid to the extent of about 80% of the 24h excretion in the squirrel monkey, pig, dog, ferret, hedgehog and pigeon, the other 20% being found as benzoyl glucuronide and benzoic acid, the latter possibly arising by decomposition of the former. 5. On increasing the dose of benzoic acid to 200mg/kg in the ferret, the proportion of benzoyl glucuronide excreted increased and that of hippuric acid decreased. This did not occur in the rabbit, which excreted 200mg/kg almost entirely as hippuric acid. It appears that the hedgehog and ferret are like the dog in respect to their metabolism of benzoic acid. 6. The Indian fruit bat produced only traces of hippuric acid and possibly has a defect in the glycine conjugation of benzoic acid. The main metabolite in this animal (dose 50mg/kg) was benzoyl glucuronide. 7. The chicken, side-necked turtle and gecko converted benzoic acid mainly into ornithuric acid, but all three species also excreted smaller amounts of hippuric acid.     

UDP-glucuronyltransferase activity towards oestriol in fresh and cultured foetal tissues from man and other species

• 1.1. UDP-glucuronyltransferase activity towards oestriol has been demonstrated in liver preparations from foetal and adult human and mouse, and from chick embryo and chick. It was also found in foetal human kidney and gut, but appeared absent from placenta.
• 2.2. In human foetal liver and kidney levels of UDP-glucuronyltransferase activity towards oestriol were as low as those towards o-aminophenol, and developed with age.
• 3.3. No UDP-glucosyltransferase activity towards oestriol was detected in human foetal preparations.
• 4.4. UDP-glucuronyltransferase activity towards oestriol develops precociously in cultures of chick embryo liver; in cultures of human foetal liver the transferase activity towards oestriol declines whilst increasing towards o-aminophenol.
• 5.5. Pre-treatment with phenobarbital increased UDP-glucuronyltransferase activity towards oestriol in chick embryo liver, both in ovo and in culture. Pre-treatment with phenobarbital increased this activity in maternal mouse liver but not in foetal liver, in utero or in culture, nor in cultured human foetal liver.
• 6.6. UDP-glucuronyltransferase activities towards oestriol and towards o-amino phenol differ markedly in development, in culture and in response to phenobarbital pre-treatment and activation procedures; heterogeneity of the enzyme is probably responsible.

     

The metabolic fate of the anti-androgenic agent, oxendolone, in man

After intramuscular administration of 16 beta-ethyl-17 beta-hydroxy-4-4-[4-14C]estren-3-one (14C-oxendolone; 300 mg) to 3 human subjects, excretion of 14C was very slow and incomplete despite a 20-day sample collection period. During this time, means of 37% and 21% of the administered 14C were recovered in urine and faeces, respectively, and if excretion continued at the same rate, approximately 90% of the administered 14C would have been excreted during 5-12 weeks. Peak plasma 14C concentrations were reached at 3-6 days after dosing, when they represented 0.2-1.1 micrograms equiv./ml, and declined very slowly thereafter with a half-life of 5.0-6.6 days. Concentrations of unconjugated drug-related steroids circulating in plasma never exceeded about 0.1 microgram/ml. Mass spectroscopic analysis of isolated urinary and faecal metabolites indicated that the principal routes of biotransformation of oxendolone in man are similar to those of the endogenous androgens-namely, reduction of the 4,5-double bond, further reduction of the saturated 3-ketone to the 3 alpha-hydroxysteroid, and oxidation of the 17 beta-alcohol to the corresponding ketone, followed by conjugation, mainly with glucuronic acid, and excretion in the urine and bile.     

An analysis of class I antigens of man and other species by one-dimensional IEF and immunoblotting

A procedure for the molecular identification of MHC class I products based on 1-D IEF and subsequent immunoblotting is described. Optimal conditions for 1-D IEF, the electrophoretic transfer of proteins out of denaturing, nonionic detergent-containing gels to nitrocellulose, and the requisite antibodies, both polyclonal and monoclonal, for the visualization of class I heavy chains have been established. Cross-reactivity of antibodies has enabled the biochemical analysis of class I heavy chains in the dog. The procedure reported here requires modest amounts of cells and allows a rapid molecular characterization of class I heavy chain polymorphisms in man and other species without the need for radiochemical methods.Abbreviations used in this paper FCS fetal calf serum - MHC major histocompatibility complex - NP-40 Nonidet P-40 - PBL peripheral blood lymphocytes - PHA phytohemagglutinin - RaHC rabbit anti-heavy chain serum - TX-114 Triton X-114 - 1-D IEF one-dimensional isoelectric focusing     

The K-turn motif in riboswitches and other RNA species

The kink turn is a widespread structure motif that introduces a tight bend into the axis of duplex RNA. This generally functions to mediate tertiary interactions, and to serve as a specific protein binding site. K-turns or closely related structures are found in at least seven different riboswitch structures, where they function as key architectural elements that help generate the ligand binding pocket. This article is part of a Special Issue entitled: Riboswitches.     

The fate of sheep-dispersed seeds: Plant species emergence and spatial patterns

Sheep epizoochory has often been proposed as an important vector which can help to overcome the dispersal limitation of plants in fragmented landscapes. In order to evaluate the contribution of herbivores to recruitment especially of target species, the dispersal and post-dispersal fate of such seeds must be known. In a field experiment sheep with seeds of mainly target species (experimentally attached to their coats) were present at three sand plots for 24 h. Natural epizoochorous dispersal was already shown for most of the species in our study area. Seed detachment, trampling intensity and seed shadow were measured; seedling emergence and survival were recorded over an 8-month period. In addition, the effect of sheep trampling on seedling emergence and survival of two threatened species, Jurinea cyanoides and Koeleria glauca, were studied.     

Polymorphism of hyaluronidase in serum from man, various mouse strains and other vertebrate species revealed by electrophoresis

Polymorphism of hyaluronidase (EC 3.2.1.35) was detected in the serum from 6 out of 20 vertebrate species by electrophoretic analysis. Electrophoresis was performed on a hyaluronan-containing polyacrylamide gel, that visualizes hyaluronidase activity upon incubation at acid pH. No hyaluronidase activity was detected in the sera of horse, swine, cattle, goat, sheep, rabbit, chicken, Triton alpestris, Triton palmatus, Triton vulgaris, pleurodeles, axolotl, eel and dog-fish. The 6 positive sera were from man, mouse, rat, Syrian hamster, dog and Triton cristatus. In each of these species, the electrophoretic banding pattern of hyaluronidase was different, as was the activity per unit volume of serum. Furthermore, in mice, the 12 strains analyzed could be divided into 3 groups, containing the following numbers of hyaluronidase bands; 8 (BALB/c/J, BALB/c/By, ICFW, SW, XVIInc/Z), 5 (DBA/2 Mrc Ico, DBA/2 Mrc Ico nu/nu, B10.D2/nSn), and 1 (C57B/Rho Ico, C57BL/6/By, C57BL/6/J Ico, C57BL/6/J Ico nu/nu). Human serum generally displayed only 1 band, although there was a 2nd faint band in a few cases and a 3rd in 1 case. Rat serum displayed 4 bands, Syrian hamster serum, 3, and dog and Triton cristatus serum, 1.