145 resultados para Amphetamine


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Iptakalim is a novel putative adenosine triphosphate (ATP)-sensitive potassium (KATP) channel opener. In the brain, iptakalim is thought to act on the neuronal and astrocytic plasma membrane and/or mitochondrial KATP channels. Because iptakalim demonstrates an action on the regulation of dopamine and glutamate release in the forebrain regions, we examined its potential antipsychotic efficacy in several preclinical tests. First, we show that iptakalim is effective in reducing amphetamine- and phencyclidine-induced hyperlocomotion as well as selectively disrupting conditioned avoidance responding. Next, we show that combined iptakalim and amphetamine treatment produces a reduction on prepulse inhibition of acoustic startle and this combined drug effect is also found with haloperidol, but not with clozapine. Finally, we show that iptakalim and clozapine preferentially increase c-Fos expression in the medial prefrontal cortex, nucleus accumbens and lateral septal nucleus, whereas haloperidol induces a greater increase in the nucleus accumbens, the dorsolateral striatum and lateral septal nucleus. Collectively, our findings indicate that iptakalim is likely to be a potential antipsychotic drug with distinct mechanisms of action. This study also suggests that neuronal and astrocytic plasma membrane and/or mitochondrial KATP channels may be a novel target that deserves attention for antipsychotic drug development. Future research using other sensitive tests is needed to confirm this property of iptakalim.

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Diethylpropion (DEP) is a stimulant drug widely used for weight control in Brazil and other American countries. However, its effects on behavior and addiction potential are not yet well known. Data suggest that sensitization resulting from pre-exposure to psychostimulants could be a possible risk factor in subsequent drug addiction. The purpose of this investigation was to verify whether pre-exposure to DEP would sensitize rats to the motor activating effect and to the rewarding value of DEP. Two experiments were conducted. In both experiments rats were pre-exposed to DEP (20 mg/kg) or vehicle for 7 consecutive days. The acute effect of DEP (0.0, 1.0, 2.5 or 5.0 mg/kg) on motor activity (Experiment 1) and induction of Conditioned Place Preference-CPP (Experiment 2) were then measured. Results from Experiment 1 showed that 2.5 and 5.0 mg/kg DEP increased motor activity. Sensitization of this motor effect was observed. In Experiment 2, the doses of 2.5 and 5.0 mg/kg DEP induced CPP, indicating their rewarding value. However, no sensitization effect was observed. The results suggest that DEP at low doses has psychostimulant and rewarding properties. It is recommended that more effort should be dedicated to elucidating DEP abuse Potential. (c) 2008 Elsevier Inc. All rights reserved.

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OBJECTIVE: To analyze drug use trends among college students in 1996, 2001 and 2009. METHODS: A cross-sectional epidemiological study with a multistage stratified cluster sample with 9,974 college students was conducted in the city of Sao Paulo, southeastern Brazil. An anonymous self-administered questionnaire was used to collect information on drug use assessed in lifetime, the preceding 12 months and the preceding 30 days. The Bonferroni correction was used for multiple comparisons of drug use rates between surveys. RESULTS: There were changes in the lifetime use of tobacco and some other drugs (hallucinogens [6.1% to 8.8%], amphetamines [4.6% to 8.7%], and tranquilizers [5.7% to 8.2%]) from 1996 to 2009. Differences in the use of other drugs over the 12 months preceding the survey were also seen: reduced use of inhalants [9.0% to 4.8%] and increased use of amphetamines [2.4% to 4.8%]. There was a reduction in alcohol [72.9% to 62.1%], tobacco [21.3% to 17.2%] and marijuana [15.0% to 11.5%] use and an increase in amphetamine use [1.9% to 3.3%] in the preceeding 30 days. CONCLUSIONS: Over the 13-year study period, there was an increase in lifetime use of tobacco, hallucinogens, amphetamines, and tranquilizers. There was an increase in amphetamine use and a reduction in alcohol use during the preceding 12 months. There was an increase in amphetamine use during the preceding 30 days.

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Sintetizada pela primeira vez na Alemanha, a anfetamina é, portanto, droga sintética, fabricada em laboratório, a qual, por sua vez, estimula o sistema nervoso central. A anfetamina faz com que o cérebro funcione mais rápido do que o normal, acarretando um estado hiperativo nos indivíduos usuários.

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Das Auftreten von Psychostimulantien im Straßenverkehr und eine Beeinträchtigung der Fahrtüchtigkeit durch diese spielt in Deutschland zunehmend eine wichtige Rolle. Das Ziel der hier vorliegenden Arbeit war es retrospektiv die dokumentierten Ausfallserscheinungen von Personen unter Einfluss von Amphetaminderivaten anhand von ärztlichen Untersuchungsbögen, die bei polizeilich angeordneten Blutentnahmen ausgefüllt werden, des Zeitraums 2001 bis 2005 in Rheinland-Pfalz zu untersuchen. Aufgrund der hohen Fallzahlen konnten sehr strenge Auswahlkriterien angewandt werden, sodass lediglich reine Amphetaminderivat-Intoxikationen (Amphetamin, Methamphetamin, MDA, MDMA, MDE, MBDB) bei 923 Personen untersucht werden konnten. Es zeigten sich als verkehrsrelevante Beeinflussung die Erweiterung der Pupille mit einer geringeren Lichtreagibilität, eine Verlängerung des Drehnachnystagmus sowie eine Unsicherheit beim Rombergtest. Eine Dosis-Wirkungs-Beziehung konnte lediglich bei der Pupillenweite ansatzweise gefunden werden. Bei MDMA zeigte sich ein deutlich stärkerer Einfluss auf die Pupillenweitenregulation als bei Amphetamin. Die zur Detektion von alkoholbedingten Ausfallserscheinungen sinnvollen Gleichgewichts- und Koordinationstests waren im Falle der hier betrachteten Psychstimulantien nicht aussagekräftig. Es erscheint empfehlenswert die durchgeführten Untersuchungen mit Hilfe von einheitlichen Lichtverhältnissen und festgelegten Untersuchungsprozedere zu standardisieren ggf. auch durch die Einführung der Videookulographie. Die Einführung eines Reaktionstests sollte in Erwägung gezogen werden.

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Since the late 1990s and early 2000s, derivatives of well-known designer drugs as well as new psychoactive compounds have been sold on the illicit drug market and have led to intoxications and fatalities. The LC-MS/MS screening method presented covers 31 new designer drugs as well as cathinone, methcathinone, phencyclidine, and ketamine which were included to complete the screening spectrum. All but the last two are modified molecular structures of amphetamine, tryptamine, or piperazine. Among the amphetamine derivatives are cathinone, methcathinone, 3,4-DMA, 2,5-DMA, DOB, DOET, DOM, ethylamphetamine, MDDMA, 4-MTA, PMA, PMMA, 3,4,5-TMA, TMA-6 and members of the 2C group: 2C-B, 2C-D, 2C-H, 2C-I, 2C-P, 2C-T-2, 2C-T-4, and 2C-T-7. AMT, DPT, DiPT, MiPT, DMT, and 5MeO-DMT are contained in the tryptamine group, BZP, MDBP, TFMPP, mCPP, and MeOPP in the piperazine group. Using an Applied Biosystems LC-MS/MS API 365 TurboIonSpray it is possible to identify all 35 substances. After addition of internal standards and mixed-mode solid-phase extraction the analytes are separated using a Synergi Polar RP column and gradient elution with 1 mM ammonium formate and methanol/0.1% formic acid as mobile phases A and B. Data acquisition is performed in MRM mode with positive electro spray ionization. The assay is selective for all tested substances. Limits of detection were determined by analyzing S/N-ratios and are between 1.0 and 5.0 ng/mL. Matrix effects lie between 65% and 118%, extraction efficiencies range from 72% to 90%.

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Ritalin® (methylphenidate) is an amphetamine-like prescription stimulant commonly used in the treatment of attention deficit hyperactivity disorder in children and adults. Recently, the recreational use of Ritalin has increased, particularly among young adults. Well-known symptoms of intoxication include signs of sympathetic nervous stimulation, such as agitation, anxiety, tachycardia, hypertension, headache, tremor, and dizziness. This case report describes oral dyskinesia as a rare presentation of Ritalin intoxication, with the review of pathophysiology and some epidemiological data.

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Ventral mesencephalic (VM) precursor cells are of interest in the search for transplantable dopaminergic neurons for cell therapy in Parkinson's disease (PD). In the present study we investigated the survival and functional capacity of in vitro expanded, primary VM precursor cells after intrastriatal grafting to a rat model of PD. Embryonic day 12 rat VM tissue was mechanically dissociated and cultured for 4 or 8 days in vitro (DIV) in the presence of FGF2 (20 ng/ml), FGF8 (20 ng/ml) or without mitogens (control). Cells were thereafter differentiated for 6 DIV by mitogen withdrawal and addition of serum. After differentiation, significantly more tyrosine hydroxylase-immunoreactive (TH-ir), dopamine-producing neurons were found in FGF2- and FGF8-expanded cultures compared to controls. Moreover, expansion for 4 DIV resulted in significantly more TH-ir cells than expansion for 8 DIV both for FGF2 (2.4 fold; P<0.001) and FGF8 (3.8 fold; P<0.001) treated cultures. The functional potential of the expanded cells (4 DIV) was examined after grafting into striatum of aged 6-hydroxydopamine-lesioned rats. Amphetamine-induced rotations performed 3, 6 and 9 weeks postgrafting revealed that grafts of FGF2-expanded cells induced a significantly faster and better functional recovery than grafts of FGF8-expanded cells or control cells (P<0.05 for both). Grafts of FGF2-expanded cells also contained significantly more TH-ir cells than grafts of FGF8-expanded cells (P<0.05) or control cells (P<0.01). In conclusion, FGF2-mediated pregrafting expansion of primary VM precursor cells considerably improves dopaminergic cell survival and functional restoration in a rat model of PD.

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Ventral mesencephalon (VM) of fetal rat and human origin grown as free-floating roller-tube (FFRT) cultures can survive subsequent grafting to the adult rat striatum. To further explore the functional efficacy of such grafts, embryonic day 13 ventral mesencephalic tissue was grafted either after 7 days in culture or directly as dissociated cell suspensions, and compared with regard to neuronal survival and ability to normalize rotational behavior in adult rats with unilateral 6-hydroxydopamine (6-OHDA) lesions. Other lesioned rats received injections of cell-free medium and served as controls. The amphetamine-induced rotational behavior of all 6-OHDA-lesioned animals was monitored at various time points from 18 days before transplantation and up to 80 days after transplantation. Tyrosine hydroxylase (TH) immunostaining of the histologically processed brains served to assess the long-term survival of grafted dopaminergic neurons and to correlate that with the behavioral effects. Additional cultures and acutely prepared explants were also fixed and stored for histological investigation in order to estimate the loss of dopaminergic neurons in culture and after transplantation. Similar behavioral improvements in terms of significant reductions in amphetamine-induced rotations were observed in rats grafted with FFRT cultures (127%) and rats grafted with cell suspensions (122%), while control animals showed no normalization of rotational behavior. At 84 days after transplantation, there were similar numbers of TH-immunoreactive (TH-ir) neurons in grafts of cultured tissue (775 +/- 98, mean +/- SEM) and grafts of fresh, dissociated cell suspension (806 +/- 105, mean +/- SEM). Cell counts in fresh explants, 7-day-old cultures, and grafted cultures revealed a 68.2% loss of TH-ir cells 7 days after explantation, with an additional 23.1% loss after grafting, leaving 8.7% of the original number of TH-ir cells in the intracerebral grafts. This is to be compared with a survival rate of 9.1% for the TH-ir cells in the cell-suspension grafts. Immunostaining for the calcium-binding proteins calretinin, calbindin, and parvalbumin showed no differences in the neuronal expression of these proteins between the two graft types. In conclusion, we found comparable dopaminergic cell survival and functional effects of tissue-culture grafts and cell-suspension grafts, which currently is the type of graft most commonly used for experimental and clinical grafting. In this sense the result is promising for the development of an effective in vitro storage of fetal nigral tissue, which at the same time would allow neuroprotective and neurotrophic treatment prior to intracerebral transplantation.

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Free-floating roller tube cultures of human fetal (embryonic age 6-10 weeks post-conception) and rat fetal (embryonic day 13) ventral mesencephalon were prepared. After 7-15 days in vitro, the mesencephalic tissue cultures were transplanted into the striatum of adult rats that had received unilateral injections of 6-hydroxydopamine into the nigrostriatal bundle 3-5 weeks prior to transplantation. Graft survival was assessed in tyrosine hydroxylase (TH)-immunostained serial sections of the grafted brains up to post-transplantation week 4 for the human fetal xenografts and post-transplantation week 11 for the rat fetal allografts. D-amphetamine-induced rotation was monitored up to 10 weeks after transplantation in the allografted animals and compared with that of lesioned-only control animals. All transplanted animals showed large, viable grafts containing TH-immunoreactive (ir) neurons. The density of TH-ir neurons in the human fetal xenografts and in rat fetal allografts was similar. A significant amelioration of the amphetamine-induced rotation was observed in the animals that received cultured tissue allografts. These results promote the feasibility of in vitro maintenance of fetal human and rat nigral tissue prior to transplantation using the free-floating roller tube technique.

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Transplantation of fetal dopaminergic (DA) neurons offers an experimental therapy for Parkinson's disease (PD). The low availability and the poor survival and integration of transplanted cells in the host brain are major obstacles in this approach. Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor with growth- and survival-promoting capabilities for developing DA neurons. In the present study, we examined whether pretreatment of ventral mesencephalic (VM) free-floating roller tube (FFRT) cultures with GDNF would improve graft survival and function. For that purpose organotypic cultures of E14 rat VM were grown for 2, 4 or 8 days in the absence (control) or presence of GDNF [10 ng/ml] and transplanted into the striatum of 6-hydroxydopamine-lesioned rats. While all groups of rats showed a significant reduction in d-amphetamine-induced rotations at 6 weeks posttransplantation a significantly improved graft function was observed only in the days in vitro (DIV) 4 GDNF pretreated group compared to the control group. In addition, no statistical significant differences between groups were found in the number of surviving tyrosine hydroxylase-immunoreactive (TH-ir) neurons assessed at 9 weeks posttransplantation. However, a tendency for higher TH-ir fiber outgrowth from the transplants in the GDNF pretreated groups as compared to corresponding controls was observed. Furthermore, GDNF pretreatment showed a tendency for a higher number of GIRK2 positive neurons in the grafts. In sum, our findings demonstrate that GDNF pretreatment was not disadvantageous for transplants of embryonic rat VM with the FFRT culture technique but only marginally improved graft survival and function.

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BACKGROUND: The recreational use of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) among adolescents and young adults has become increasingly prevalent in recent years. While evidence suggests that the long-term consequences of MDMA use include neurodegeneration to serotonergic and, possibly, dopaminergic pathways, little is known about susceptibility, such as behavioral sensitization, to MDMA. METHODS: The objectives of this study were to examine the dose-response characteristics of acute and chronic MDMA administration in rats and to determine whether MDMA elicits behavioral sensitization and whether it cross-sensitizes with amphetamine and methylphenidate. Adult male Sprague-Dawley rats were randomly divided into three MDMA dosage groups (2.5 mg/kg, 5.0 mg/kg, and 10.0 mg/kg) and a saline control group (N = 9/group). All three MDMA groups were treated for six consecutive days, followed by a 5-day washout, and subsequently re-challenged with their respective doses of MDMA (day 13). Rats were then given an additional 25-day washout period, and re-challenged (day 38) with similar MDMA doses as before followed by either 0.6 mg/kg amphetamine or 2.5 mg/kg methylphenidate on the next day (day 39). Open-field locomotor activity was recorded using a computerized automated activity monitoring system. RESULTS: Acute injection of 2.5 mg/kg MDMA showed no significant difference in locomotor activity from rats given saline (control group), while animals receiving acute 5.0 mg/kg or 10.0 mg/kg MDMA showed significant increases in locomotor activity. Rats treated chronically with 5.0 mg/kg and 10.0 mg/kg MDMA doses exhibited an augmented response, i.e., behavioral sensitization, on experimental day 13 in at least one locomotor index. On experimental day 38, all three MDMA groups demonstrated sensitization to MDMA in at least one locomotor index. Amphetamine and methylphenidate administration to MDMA-sensitized animals did not elicit any significant change in locomotor activity compared to control animals. CONCLUSION: MDMA sensitized to its own locomotor activating effects but did not elicit any cross-sensitization with amphetamine or methylphenidate.

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BACKGROUND New psychoactive substances (NPS) have become increasingly prevalent and are sold in internet shops as 'bath salts' or 'research chemicals' and comprehensive bioanalytical methods are needed for their detection. METHODOLOGY We developed and validated a method using LC and MS/MS to quantify 56 NPS in blood and urine, including amphetamine derivatives, 2C compounds, aminoindanes, cathinones, piperazines, tryptamines, dissociatives and others. Instrumentation included a Synergi Polar-RP column (Phenomenex) and a 3200 QTrap mass spectrometer (AB Sciex). Run time was 20 min. CONCLUSION A novel method is presented for the unambiguous identification and quantification of 56 NPS in blood and urine samples in clinical and forensic cases, e.g., intoxications or driving under the influence of drugs.