Records |
Author |
Matzke, S.M.; Oubre, J.L.; Caranto, G.R.; Gentry, M.K.; Galbicka, G. |
Title |
Behavioral and immunological effects of exogenous butyrylcholinesterase in rhesus monkeys |
Type |
Journal Article |
Year |
1999 |
Publication |
Pharmacology, Biochemistry, and Behavior |
Abbreviated Journal |
Pharmacol Biochem Behav |
Volume |
62 |
Issue |
3 |
Pages |
523-530 |
Keywords |
Animals; Antibody Formation/drug effects; Behavior, Animal/*drug effects; Butyrylcholinesterase/*immunology/pharmacokinetics/*pharmacology; Cognition/drug effects; Color Perception/drug effects; Conditioning, Operant/drug effects; Discrimination Learning/drug effects; Half-Life; Horses; Humans; Macaca mulatta; Male |
Abstract |
Although conventional therapies prevent organophosphate (OP) lethality, laboratory animals exposed to such treatments typically display behavioral incapacitation. Pretreatment with purified exogenous human or equine serum butyrylcholinesterase (Eq-BuChE), conversely, has effectively prevented OP lethality in rats and rhesus monkeys, without producing the adverse side effects associated with conventional treatments. In monkeys, however, using a commercial preparation of Eq-BuChE has been reported to incapacitate responding. In the present study, repeated administration of commercially prepared Eq-BuChE had no systematic effect on behavior in rhesus monkeys as measured by a six-item serial probe recognition task, despite 7- to 18-fold increases in baseline BuChE levels in blood. Antibody production induced by the enzyme was slight after the first injection and more pronounced following the second injection. The lack of behavioral effects, the relatively long in vivo half-life, and the previously demonstrated efficacy of BuChE as a biological scavenger for highly toxic OPs make BuChE potentially more effective than current treatment regimens for OP toxicity. |
Address |
Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA |
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English |
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Edition |
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ISSN |
0091-3057 |
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Notes |
PMID:10080246 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
4064 |
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Author |
Machnik, M.; Hegger, I.; Kietzmann, M.; Thevis, M.; Guddat, S.; Schanzer, W. |
Title |
Pharmacokinetics of altrenogest in horses |
Type |
Journal Article |
Year |
2007 |
Publication |
Journal of Veterinary Pharmacology and Therapeutics |
Abbreviated Journal |
J Vet Pharmacol Ther |
Volume |
30 |
Issue |
1 |
Pages |
86-90 |
Keywords |
Administration, Oral; Animals; Chromatography, Liquid/veterinary; Doping in Sports/prevention & control; Horses/*metabolism; Male; Mass Spectrometry/veterinary; Progesterone Congeners/administration & dosage/blood/*pharmacokinetics/urine; Reproducibility of Results; Substance Abuse Detection/veterinary; Trenbolone/administration & dosage/*analogs & derivatives/blood/pharmacokinetics/urine |
Abstract |
The Federation Equestre Internationale has permitted the use of altrenogest in mares for the control of oestrus. However, altrenogest is also suspicious to misuse in competition horses for its potential anabolic effects and suppression of typical male behaviour, and thus is a controlled drug. To investigate the pharmacokinetics of altrenogest in horses we conducted an elimination study. Five oral doses of 44 mug/kg altrenogest were administered to 10 horses at a dose interval of 24 h. Following administration blood and urine samples were collected at appropriate intervals. Altrenogest concentrations were measured by liquid chromatography-tandem mass spectrometry. The plasma levels of altrenogest reached maximal concentrations of 23-75 ng/mL. Baseline values were achieved within 3 days after the final administration. Urine peak concentrations of total altrenogest ranged from 823 to 3895 ng/mL. Twelve days after the final administration concentrations were below the limit of detection (ca 2 ng/mL). |
Address |
Institute of Biochemistry, German Sport University, Cologne, Germany. m.machnik@biochem.dshs-koeln.de |
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ISSN |
0140-7783 |
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Notes |
PMID:17217407 |
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no |
Call Number |
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Serial |
1841 |
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Author |
Wilson, M.T.; Silvestrini, M.C.; Morpurgo, L.; Brunori, M. |
Title |
Electron transfer kinetics between Rhus vernicifera stellacyanin and cytochrome c (horse heart cytochrome c and Pseudomonas cytochrome c551) |
Type |
Journal Article |
Year |
1979 |
Publication |
Journal of Inorganic Biochemistry |
Abbreviated Journal |
J Inorg Biochem |
Volume |
11 |
Issue |
2 |
Pages |
95-100 |
Keywords |
Animals; Copper; Cytochrome c Group/*metabolism; Electron Transport; Kinetics; Metalloproteins/*metabolism; Plant Proteins/*metabolism; *Plants, Toxic; Pseudomonas aeruginosa/*metabolism; Toxicodendron/*metabolism |
Abstract |
The electron transfer reactions between Rhus vernicifera stellacyanin and either horse heart cytochrome c or Pseudomonas aeruginosa cytochrome c551 were investigated by rapid reaction techniques. The time course of electron transfer is monophasic under all conditions, and thus consistent with a simple formulation of the reaction. Both stopped-flow and temperature-jump experiments yield equilibrium constants in reasonable agreement with values calculated from the redox potentials. The differences in reaction rate between the two cytochromes and stellacyanin are discussed in terms of the Marcus theory. |
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English |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0162-0134 |
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Medium |
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Conference |
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Notes |
PMID:228006 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
3879 |
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Author |
Czerlinski, G.H.; Wagner, M.; Erickson, J.O.; Theorell, H. |
Title |
Chemical relaxation studies on the system liver alcohol dehydrogenase, NADH and imidazole |
Type |
Journal Article |
Year |
1975 |
Publication |
Acta Chemica Scandinavica. Series B: Organic Chemistry and Biochemistry |
Abbreviated Journal |
Acta Chem Scand B |
Volume |
29 |
Issue |
8 |
Pages |
797-810 |
Keywords |
Alcohol Oxidoreductases/*metabolism; Animals; Computers; Hydrogen-Ion Concentration; Imidazoles/*metabolism; Kinetics; Liver/enzymology/*metabolism; Mathematics; Models, Chemical; NAD/*metabolism; Time Factors |
Abstract |
Several years ago, Theorell and Czerlinski conducted experiments on the system of horse liver alcohol dehydrogenase, reduced nicotinamide adenine dinucleotide and imidazole, using the first version of the temperature jump apparatus with detection of changes in fluorescence. These early experiments were repeated with improved instrumentation and confirmed the early experiments in general terms. However, the improved detection system allowed to measure a slight concentration dependence of the relaxation time of around 3 ms. Furthermore, the chemical relaxation time was smaller than the one determined earlier (by factor 2). The data were evaluated much more rigorously than before, allowing an appropriate interpretation of the results. The observed relaxation time is largely due to rate constants in an interconversion of ternary complexes, which are faster than three (of the four) dissociation rate constants, determined previously by Theorell and McKinley-McKee.1,2 This fact contributed to earlier difficulties of finding any concentration dependence. However, the binding of imidazole to the binary enzyme-coenzyme complex can be made to couple kinetically into the interconversion rate of the two ternary complexes. The observed signal derives largely from the ternary complex(es). A substantial fluorescence signal change is associated with the observed relaxation process, suggesting a relocation of the imidazole in reference to the nicotinamide moiety of the bound coenzyme. Nine models are considered with two types of coupling of pre-equilibria (none-all). Quantitative evaluations favor the model with two ternary complexes connected by an interconversion outside the four-step (bimolecular) cycle. The ternary complex outside the cycle has much higher fluorescence yield than the one inside. The interconversion equilibrium is near unity for imidazole. If it would be shifted very much to the side of the “dead-end” complex (as in isobutyramide?!), stimulating action could not take place. |
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English |
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Series Editor |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0302-4369 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
PMID:882 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
3887 |
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Author |
Hubbell, J.A.E.; Muir, W.W. |
Title |
Antagonism of detomidine sedation in the horse using intravenous tolazoline or atipamezole |
Type |
Journal Article |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
Volume |
38 |
Issue |
3 |
Pages |
238-241 |
Keywords |
Animals; Behavior, Animal/drug effects/physiology; Dose-Response Relationship, Drug; Double-Blind Method; Horses/*physiology; Hypnotics and Sedatives/*antagonists & inhibitors; Imidazoles/*antagonists & inhibitors/*pharmacology; Infusions, Intravenous/veterinary; Kinetics; Safety; Tolazoline/*pharmacology; Videotape Recording |
Abstract |
REASONS FOR PERFORMING STUDY: The ability to shorten the duration of sedation would potentially improve safety and utility of detomidine. OBJECTIVES: To determine the effects of tolazoline and atipamezole after detomidine sedation. HYPOTHESIS: Administration of tolazoline or atipamezole would not affect detomidine sedation. METHODS: In a randomised, placebo-controlled, double-blind, descriptive study, detomidine (0.02 mg/kg bwt i.v.) was administered to 6 mature horses on 4 separate occasions. Twenty-five mins later, each horse received one of 4 treatments: Group 1 saline (0.9% i.v.) as a placebo control; Group 2 atipamezole (0.05 mg/kg bwt i.v.); Group 3 atipamezole (0.1 mg/kg bwt i.v.); and Group 4 tolazoline (4.0 mg/kg bwt i.v.). Sedation, muscle relaxation and ataxia were scored by 3 independent observers at 9 time points. Horses were led through an obstacle course at 7 time points. Course completion time was recorded and the ability of the horse to traverse the course was scored by 3 independent observers. Horses were videotaped before, during and after each trip through the obstacle course. RESULTS: Atipamezole and tolazoline administration incompletely antagonised the effects of detomidine, but the time course to recovery was shortened. CONCLUSIONS AND POTENTIAL RELEVANCE: Single bolus administration of atipamezole or tolazoline produced partial reversal of detomidine sedation and may be useful for minimising detomidine sedation. |
Address |
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, 601 Tharp Street, Columbus, Ohio 43210, USA |
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English |
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Series Issue |
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Edition |
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ISSN |
0425-1644 |
ISBN |
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Area |
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Conference |
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Notes |
PMID:16706278 |
Approved |
no |
Call Number |
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Serial |
1869 |
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Author |
Ryan, C.T.; Schaer, B.L.D.; Nunamaker, D.M. |
Title |
A novel wireless data acquisition system for the measurement of hoof accelerations in the exercising horse |
Type |
Journal Article |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
Volume |
38 |
Issue |
7 |
Pages |
671-674 |
Keywords |
*Acceleration; Animals; Biomechanics; Equipment and Supplies/*veterinary; Hoof and Claw/*physiology; Horses/*physiology; Kinetics; Musculoskeletal Physiology; Physical Conditioning, Animal/*physiology; Running/physiology |
Abstract |
REASONS FOR PERFORMING STUDY: A device is needed to safely and wirelessly evaluate accelerations experienced by the horse hoof under a variety of surface conditions with the horse exercising at training or racing speeds. OBJECTIVES: To develop a miniaturised wireless data acquisition system (WDAS) which reliably records hoof accelerations and the times over which they occur in a minimally invasive manner in the exercising Thoroughbred. METHODS: The following criteria were set for device development: production of a lightweight and minimally invasive system, which provides an adequate acceleration range, appropriate frequency response to capture high speed events, and compatibility with a low power wireless telemetry system. Following device development, the WDAS was calibrated, and tested in 6 Thoroughbred horses over a variety of surfaces. RESULTS: Collection of acceleration in seven trials using 6 horses over a variety of surfaces resulted in repeatable acceleration data with respect to the overall characteristic shape of the impact profile. Impact accelerations varied with surface, ranging 34.8-191.7 g. Accelerations on take off were in a similar range, although higher in some trials. Peak impact accelerations tended to larger over the grass paddock surface, than either the indoor arena or the dirt track. During dirt track trials, accelerations on take-off were often comparably larger than those observed on impact within the same footfall. CONCLUSIONS: This study reports the development of a wireless system that successfully measures hoof acceleration in a minimally invasive manner over a variety of surface and exercise conditions. POTENTIAL RELEVANCE: The WDAS will be used in further studies to evaluate various components of the horse-racetrack interface, in an attempt to identify risk factors for musculoskeletal injury in the Thoroughbred racehorse. |
Address |
Richard S. Reynolds, Jr. Comparative Orthopedic Research Laboratory, Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania 19348, USA |
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English |
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ISSN |
0425-1644 |
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Notes |
PMID:17228584 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
4023 |
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Author |
Chiba, K.; Ikai, A.; Kawamura-Konishi, Y.; Kihara, H. |
Title |
Kinetic study on myoglobin refolding monitored by five optical probe stopped-flow methods |
Type |
Journal Article |
Year |
1994 |
Publication |
Proteins |
Abbreviated Journal |
Proteins |
Volume |
19 |
Issue |
2 |
Pages |
110-119 |
Keywords |
Animals; Chromatography, Gel; Circular Dichroism; Horses; Kinetics; Metmyoglobin/analogs & derivatives/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Urea |
Abstract |
The refolding kinetics of horse cyanometmyoglobin induced by concentration jump of urea was investigated by five optical probe stopped-flow methods: absorption at 422 nm, tryptophyl fluorescence at around 340 nm, circular dichroism (CD) at 222 nm, CD at 260 nm, and CD at 422 nm. In the refolding process, we detected three phases with rate constants of > 1 x 10(2) s-1, (4.5-9.3) s-1, and (2-5) x 10(-3) s-1. In the fastest phase, a substantial amount of secondary structure (approximately 40%) is formed within the dead time of the CD stopped-flow apparatus (10.7 ms). The kinetic intermediate populated in the fastest phase is shown to capture a hemindicyanide, suggesting that a “heme pocket precursor” recognized by hemindicyanide must be constructed within the dead time. In the middle phase, most of secondary and tertiary structures, especially around the captured hemindicyanide, have been constructed. In the slowest phase, we detected a minor structural rearrangement accompanying the ligand-exchange reaction in the fifth coordination of ferric iron. We present a possible model for the refolding process of myoglobin in the presence of the heme group. |
Address |
Laboratory of Biodynamics, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Kanagawa, Japan |
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English |
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Edition |
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ISSN |
0887-3585 |
ISBN |
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Notes |
PMID:8090705 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3799 |
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Author |
Guo, G.L.; Moffit, J.S.; Nicol, C.J.; Ward, J.M.; Aleksunes, L.A.; Slitt, A.L.; Kliewer, S.A.; Manautou, J.E.; Gonzalez, F.J. |
Title |
Enhanced acetaminophen toxicity by activation of the pregnane X receptor |
Type |
Journal Article |
Year |
2004 |
Publication |
Toxicological sciences : an official journal of the Society of Toxicology |
Abbreviated Journal |
Toxicol Sci |
Volume |
82 |
Issue |
2 |
Pages |
374-380 |
Keywords |
Acetaminophen/pharmacokinetics/*toxicity; Analgesics, Non-Narcotic/pharmacokinetics/*toxicity; Animals; Aryl Hydrocarbon Hydroxylases/biosynthesis; Biotransformation; Blotting, Northern; Chromatography, High Pressure Liquid; Cytochrome P-450 CYP3A; Membrane Proteins; Mice; Mice, Knockout; Oxidoreductases, N-Demethylating/biosynthesis; Pregnenolone Carbonitrile/pharmacology; Receptors, Cytoplasmic and Nuclear/*drug effects; Receptors, Steroid/*drug effects; Sulfhydryl Compounds/metabolism |
Abstract |
The pregnane X receptor (PXR) is a ligand-activated transcription factor and member of the nuclear receptor superfamily. Activation of PXR represents an important mechanism for the induction of cytochrome P450 3A (CYP3A) enzymes that can convert acetaminophen (APAP) to its toxic intermediate metabolite, N-acetyl-p-benzoquinone imine (NAPQI). Therefore, it was hypothesized that activation of PXR plays a major role in APAP-induced hepatotoxicity. Pretreatment with the PXR activator, pregnenolone 16alpha-carbonitrile (PCN), markedly enhanced APAP-induced hepatic injury, as revealed by increased serum ALT levels and hepatic centrilobular necrosis, in wild-type but not in PXR-null mice. Further analysis showed that following PCN treatment, PXR-null mice had lower CYP3A11 expression, decreased NAPQI formation, and increased maintenance of hepatic glutathione content compared to wild-type mice. Thus, these results suggest that PXR plays a critical role in APAP-induced hepatic toxicity, probably by inducing CYP3A11 expression and hence increasing bioactivation. |
Address |
Laboratory of Metabolism, CCR, NCI, NIH, Bethesda, Maryland 20892, USA |
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English |
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Edition |
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ISSN |
1096-6080 |
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Notes |
PMID:15456926 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
71 |
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Author |
Dirikolu, L.; Lehner, A.F.; Karpiesiuk, W.; Hughes, C.; Woods, W.E.; Boyles, J.; Harkins, J.D.; Troppmann, A.; Tobin, T. |
Title |
Detection, quantification, metabolism, and behavioral effects of selegiline in horses |
Type |
Journal Article |
Year |
2003 |
Publication |
Veterinary Therapeutics : Research in Applied Veterinary Medicine |
Abbreviated Journal |
Vet Ther |
Volume |
4 |
Issue |
3 |
Pages |
257-268 |
Keywords |
Administration, Oral; Animals; Behavior, Animal/drug effects; Female; Horses/*metabolism; Mass Spectrometry/veterinary; Monoamine Oxidase Inhibitors/administration & dosage/blood/*pharmacokinetics/pharmacology/urine; Selegiline/administration & dosage/blood/*pharmacokinetics/pharmacology/urine; Substance Abuse Detection/veterinary |
Abstract |
Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine using commercially available deuterated analogs of these compounds as internal standards. After administering 40 mg of selegiline orally to two horses, relatively low (<60 ng/ml) concentrations of parent selegiline, amphetamine, and methamphetamine were recovered in urine samples. However, relatively high urinary concentrations of another selegiline metabolite were found, tentatively identified as N- desmethylselegiline. This metabolite was synthesized and found to be indistinguishable from the new metabolite recovered from horse urine, thereby confirming the chemical identity of the equine metabolite. Additionally, analysis of urine samples from four horses dosed with 50 mg of selegiline confirmed that N-desmethylselegiline is the major urinary metabolite of selegiline in horses. In related behavior studies, p.o. and i.v. administration of 30 mg of selegiline produced no significant changes in either locomotor activities or heart rates. |
Address |
Department of Biomedical Sciences, College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA |
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English |
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ISSN |
1528-3593 |
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Notes |
PMID:15136987 |
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no |
Call Number |
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Serial |
1901 |
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Author |
Abbruzzetti, S.; Viappiani, C.; Sinibaldi, F.; Santucci, R. |
Title |
Kinetics of histidine dissociation from the heme Fe(III) in N-fragment (residues 1-56) of cytochrome c |
Type |
Journal Article |
Year |
2004 |
Publication |
The Protein Journal |
Abbreviated Journal |
Protein J |
Volume |
23 |
Issue |
8 |
Pages |
519-527 |
Keywords |
Animals; Cytochromes c/*chemistry; Enzyme Activation; Histidine/*chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; Lasers; Ligands; Peptide Mapping; Photolysis; Spectrophotometry |
Abstract |
We have here investigated the dissociation kinetics of the His side chains axially ligated to the heme-iron in the ferric (1-56 residues) N-fragment of horse cyt c. The ligand deligation induced by acidic pH-jump occurs as a biexponential process with different pre-exponential factors, consistent with a structural heterogeneity in solution and the presence of two differently coordinated species. In analogy with GuHCl-denatured cyt c, our data indicate the presence in solution of two ferric forms of the N-fragment characterized by bis-His coordination, as summarized in the following scheme: His18-Fe(III)-His26 <==> His18-Fe(III)-His33. We have found that the pre-exponential factors depend on the extent of the pH-jump. This may be correlated with the different pKa values shown by His26 and His33; due to steric factors, His26 binds to the heme-Fe(III) less strongly than His33, as recently shown by studies on denatured cyt c. Interestingly, the two lifetimes are affected by temperature but not by the extent of the pH-jump. The lower pKa for the deligation reaction required the use of an improved laser pH-jump setup, capable of inducing changes in H+ concentration as large as 1 mM after the end of the laser pulse. For the ferric N-fragment, close activation entropy values have been determined for the two histidines coordinated to the iron; this result significantly differs from that for GuHCl-denatured cyt c, where largely different values of activation entropy were calculated. This underlines the role played by the missing segment (residues 57-104) peptide chain in discriminating deligation of the “nonnative” His from the sixth coordination position of the metal. |
Address |
Dipartimento di Fisica, Universita degli Studi di Parma, Parco Area delle Scienze 7/A 43100 Parma, Italy |
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English |
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Edition |
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ISSN |
1572-3887 |
ISBN |
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Notes |
PMID:15648974 |
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no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3770 |
Permanent link to this record |