Pharmacological properties of some xanthone derivatives.
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A series of aminoalkanolic derivatives of xanthone were examined in some experimental models of epilepsia, i.e., pilocarpine, aminophylline and pentetrazole-induced seizures. A final objective of this research was to examine the action of these compounds on the central nervous system, namely on spontaneous locomotor activity, amphetamine-induced hyperactivity and narcotic sleep induced by hexobarbital, as well as their influence on the gamma-aminobutyric acid (GABA) level and glutamic acid decarboxylase (GAD) activity in mice brain. The most interesting were the pharmacological results of (R)-2-N-methylamino-1-butanol derivative of 7-chloro-2-methylxanthone [Id], which displayed protective activity against the seizures induced by maximum electroshock and pentetrazole induced seizures; moreover, this compound had a relatively low toxicity and did not exhibit a neurotoxic effect. The influence on the locomotor activity as well as on the amphetamine-induced locomotor hyperactivity in mice was also seen for Id. Compound Id did not decrease the GABA level in mice brain. (+info)
Differential effects of glial cell line-derived neurotrophic factor (GDNF) in the striatum and substantia nigra of the aged Parkinsonian rat.
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Injection of an adenoviral (Ad) vector encoding human glial cell line-derived neurotrophic factor (GDNF) protects dopaminergic (DA) neurons in the substantia nigra (SN) of young rats. As Parkinson's disease occurs primarily in aged populations, we examined whether chronic biosynthesis of GDNF, achieved by adenovirus-mediated delivery of a GDNF gene (AdGDNF), can protect DA neurons and improve DA-dependent behavioral function in aged (20 months) rats with progressive 6-OHDA lesions of the nigrostriatal projection. Furthermore, the differential effects of injecting AdGDNF either near DA cell bodies in the SN or at DA terminals in the striatum were compared. AdGDNF or control vector was injected unilaterally into either the striatum or SN. One week later, rats received a unilateral intrastriatal injection of 6-OHDA on the same side as the vector injection. AdGDNF injection into either the striatum or SN significantly reduced the loss of FG labelled DA neurons 5 weeks after lesion (P +info)
The relationship between dorsolateral prefrontal neuronal N-acetylaspartate and evoked release of striatal dopamine in schizophrenia.
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Schizophrenia has been linked to abnormal dopamine function, recently to excessive amphetamine-induced release of striatal dopamine, and also to pathology of prefrontal cortical neurons. It has been hypothesized that prefrontal pathology is a primary condition that leads to dopamine dysregulation. We evaluated in vivo the relationship between neuronal integrity in dorsolateral prefrontal cortex, assessed as N-acetylaspartate (NAA) relative concentrations measured with proton magnetic resonance spectroscopic imaging, and amphetamine-induced release of striatal dopamine, assessed with 11C-raclopride Positron Emission Tomography (PET) in patients with schizophrenia and in healthy subjects. In the patients, NAA measures in dorsolateral prefrontal cortex selectively predicted striatal displacement of 11C-raclopride after amphetamine infusions (rho = -0.76, p < .02). In contrast, NAA measures in other cortical regions and in healthy subjects did not show any correlation. These results support the hypothesis that in schizophrenia neuronal pathology of dorsolateral prefrontal cortex is directly related to abnormal subcortical dopamine function. (+info)
Rapid analysis of amphetamine, methamphetamine, MDA, and MDMA in urine using solid-phase microextraction, direct on-fiber derivatization, and analysis by GC-MS.
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A rapid, sensitive, and solvent-free procedure for the simultaneous determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), and 3,4-methylenedioxymethamphetamine (MDMA) in urine was developed using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode. A headspace vial containing the urine sample, NaOH, NaCl, and amphetamine-d3 as the internal standard was heated at 100 degrees C for 20 min. A polydimethylsiloxane fiber was maintained in the vial headspace for 10 min in order to adsorb the amphetaminic compounds, which were subsequently derivatized by exposing the fiber to trifluoroacetic anhydride for 20 min in the headspace of another vial maintained at 60 degrees C for 20 min. The trifluoroacetyl derivatives were desorbed in the GC injection port for 5 min. Several parameters were considered during the method optimization process. These included a comparison of SPME with or without headspace, the required derivatization procedure, and the influence of temperature on the headspace extraction and derivatization methods. The optimized method was validated for the four compounds tested. Calibration curves showed linearity in the range 50-1000 ng/mL (r = 0.9946-0.9999). Recovery data were 71.89-103.24%. The quantitation limits were 10 ng/mL for amphetamine and methamphetamine and 20 ng/mL for MDA and MDMA. All of these data recommend the applicability of the method for use in the analytical routine of a forensic laboratory. (+info)
Structural elucidation of an uncommon phenylethylamine analogue in urine responsible for discordant amphetamine immunoassay results.
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The present paper describes investigations following the analysis of a urine specimen containing important amounts of an unknown substance detected by gas chromatography-mass spectrometry (GC-MS) analysis. FPIA analysis was positive (cutoff 0.3 mg/L) and Triage 8 rapid test was negative (cutoff 1 mg/L) for amphetamines. Considering the GC-MS spectrum, two different molecules, for example, N-ethyl-1-(3,4-methylenedioxyphenyl)ethylamine (1) or N-ethyl-4-methoxyamphetamine (2), have been suspected. Synthesis of these two compounds was carried out together with spectral (MS, 1H and 13C NMR, IR, UV) and chromatographic (GC) characterization as well as determination of immunological cross reactivities (FPIA and Triage 8). The unknown compound present in the urine specimen has been finally identified as N-ethyl-4-methoxyamphetamine (2), an uncommon amphetamine analogue. (+info)
Detection of drug misuse--an addictive challenge.
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It is now accepted that drug misuse is a large and growing problem in the United Kingdom, some estimates of the number of regular illicit drug users being as high as three million. The aim of this paper is to provide insight into the methods used to detect drug misuse. The strategy adopted by one laboratory is described and methods of screening for, and identification of, a wide range of compounds are provided. No claim is made that this is the best approach or that the list of drugs detected is comprehensive; the range of drugs encountered is always increasing and the lists are constantly updated. It is hoped that users of toxicology laboratory services will gain an appreciation of the capabilities and limitations of the techniques available; and that those who may wish to provide such a service will find the necessary information in a readily accessible format. (+info)
Incorporation and retention of radiolabeled S-(+)-and R-(-)-methamphetamine and S(+)- and R(-)-N-(n-butyl)-amphetamine in mouse hair after systemic administration.
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We examined the incorporation of unlabeled and tritiated enantiomers of methamphetamine (MA) and a more lipophilic analog N-(n-butyl)-amphetamine (BA) into the hair of pigmented (C57) and nonpigmented (Balb/C) mice after systemic administration. We also compared the ability of extraction methods to remove unlabeled and tritiated MA and BA enantiomers from the hair. R(-)-MA, S(+)-MA, [(3)H]R(-)-MA, [(3)H]S(+)-MA, R(-)-BA, S(+)-BA, [(3)H]R-(-)-BA, and [(3)H]S-(+)-BA were each administered to C57 and Balb/C mice (23 days of age) by i.p. injection at 8.8 mg/kg daily for 3 days. At 44 days of age, hair samples from the animals were treated with a brief methanol wash, a 24-h extraction with pH 6 phosphate buffer, and a final digestion in 1 N NaOH to free residual drugs from the hair. Labeled drugs in the extracts were quantitated by liquid scintillation counting. Unlabeled drugs were quantitated by gas chromatography/mass spectrometry (GC/MS). GC/MS analysis demonstrated MA and BA to be the major (>90%) species present in the blood during the 24 h after administration. Less than 10% of the MA was N-demethylated. No p-hydroxylated metabolites were found. Blood concentrations of tritiated MA and BA enantiomers measured by liquid scintillation counting agreed well with blood concentrations of unlabeled enantiomers measured by GC/MS. Hair concentrations of S(+)-MA were greater than those of R(-)-MA in both mouse strains, paralleling blood concentrations. There were no enantiomeric differences seen with BA hair accumulation in either strain of mouse. Significantly more MA and BA enantiomers were deposited in pigmented than in nonpigmented hair. With labeled and unlabeled compounds, approximately 30% of S(+)-MA and 60% of R(-)-MA in pigmented hair could be removed by a phosphate extraction. A significant amount of drug could not be removed from the hair by extraction. Greater amounts of drug could be extracted from nonpigmented hair than pigmented. Extracted and residual MA and BA concentrations in pigmented hair were significantly greater when labeled compounds were quantitated by liquid scintillation counting than when unlabeled compounds were quantitated by GC/MS. However, radiotracer and unlabeled drug concentrations were the same in nonpigmented hair. The results demonstrate that hair pigmentation is an important determinant in MA and BA deposition, and that MA and BA deposition is not enantioselective. The data demonstrate a significant amount of MA and BA accumulated is not easily amenable to exhaustive aqueous extraction from the hair. The use of tritiated MA and BA enantiomers demonstrates that a significant amount of MA and BA stored in pigmented hair is structurally different from parent MA and BA, perhaps associated with melanin components of hair. (+info)
Selective involvement of cytochrome P450 2D subfamily in in vivo 4-hydroxylation of amphetamine in rat.
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The cytochrome P450 (P450) 2D subfamily catalyzes ring hydroxylation of amphetamines. We tested the hypothesis that P450 2D is selectively involved in amphetamine 4-hydroxylation. Urinary elimination of 4-hydroxyamphetamine and amphetamine was determined in male Sprague-Dawley rats pretreated with P450 inducers and inhibitors. The urinary 24-h metabolic ratio (amphetamine/4-hydroxyamphetamine) was not affected by the inducers 3-methylcholanthrene, isosafrole, phenobarbital, ethanol, pregnenolone-alpha-carbonitrile, and clofibrate. Isosafrole did, however, increase amphetamine elimination along with urine volume. Urinary elimination of 4-hydroxyamphetamine was significantly decreased by, and the metabolic ratio increased by, the inhibitors 1-aminobenzotriazole, CCl(4), quinidine, quinine, and primaquine. Diallyl sulfide and troleandomycin had no effect. In rat liver microsomes primaquine was shown to be an inhibitor of 2D activity. Urine 4-hydroxyamphetamine content correlated strongly (r(2) = 0. 989) with microsomal P450 2D activity in parallel-treated rats. These studies also substantiate that 4-hydroxylation of amphetamine is selectively performed by the P450 2D subfamily in the rat. (+info)