The binding of [³H]flunitrazepam (FLU) to membranes prepared from mammalian brain, retina and kidney was investigated by means of conventional filtration assay techniques. In the mouse brain a study of the ontogeny of [³H]FLU binding was conducted. Specific [³H]FLU binding was present early in development and there was a rapid increase in receptor density (Bmax) during the first 2 weeks of neonatal life. This increase could be described by the function, a·eᵏˣ, where a = 1.8 pmol/brain, k = 0.23 weeks⁻¹ and x = time in weeks (r = 0.98). By 3-4 weeks of age, adult levels of [³H]FLU binding were reached (∼115 fmol/mg tissue). Notable changes in the equilibrium dissociation constant (K(d)) during development were not observed. γ-Aminobutyric acid (GABA) has previously been shown to increase the affinity of [³H]FLU binding in the adult rat brain; in the present studies this effect was shown to be present throughout the development of the mouse brain. Kinetic analyses of the GABA enhancement of [³H]FLU binding indicated that the change in K(d) was due to a decrease in the rate constant of dissociation (k₋₁). [³H]FLU binding has been shown to occur in the mammalian retina and it has all the characteristics of cerebral [³H]FLU binding. Monosodium glutamate (MSG) is toxic to retinal neurons and it was used to ascertain the putative cellular localization of retinal BZD binding sites. Nine weeks following neonatal MSG administration, histologic evidence showed the virtual absence of ganglion cells and a marked reduction in the number of inner nuclear neurons in MSG retinae. A corresponding 73 percent decrease in GABA content and a 77 percent decrease in the Bmax of [³H]FLU were found in the retinae from MSG treated rats as compared to controls. There were no significant changes in [³H]FLU binding in the cerebella, cerebral cortices and hypothalami from MSG treated rats. The binding of [³H]FLU was characterized for the rat kidney. Binding was specific, saturable and of moderately high affinity (Bmax, ∼320 fmol/mg tissue; K(d), ∼11 nM). Drug specificity studies with renal membranes showed that inhibition of [³H]FLU binding by various BZD's did not correlate either with their pharmacologic potency as anxiolytic agents or with their potency as inhibitors of [³H]FLU binding in the brain. An intrarenal distribution of specific [³H]FLU binding was found in the bovine kidney; specific binding was greatest in the outer cortex and virtually absent in the medulla, the minor calyx and the renal artery. In rats made hypertensive by simultaneous deoxycorticosterone acetate and NaCl administration, there was a significant 35-43 percent increase in the Bmax of renal [³H]FLU binding. Binding in the cerebral cortex of these animals was unchanged. The inhibition of [³H]FLU binding by a triazolopyridazine (CL 218,872) was studied in membranes prepared from bovine retina, rat cerebral cortex, cerebellum and kidney. The affinity of CL 218,872 for the inhibition of [³H]FLU binding was greatest in the cerebellum, followed by the retina, cerebral cortex and kidney (60, 150, 200, and 1,800 nM, respectively). The slope factors (Hill coefficients) were ∼1 for the kidney, ∼0.9 for the cerebellum and ∼0.7 for the cerebral cortex and retina. A nonlinear least squares regression analysis of the data from the cerebral cortex, retina and cerebellum gave an excellent fit for a model containing 2 binding sites. In washed membrane preparations from the cerebral cortex, cerebellum and retina, Kᵢ values for CL 218,872 were significantly decreased an average of 60 percent in the presence of 100 μM GABA. (+)Bicuculline could antagonize this effect of GABA. GABA had no effect upon the Kᵢ of CL 218,872 in renal membranes.

Made available in DSpace on 2015-07-22T20:49:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-25. Added 1 bitstream(s) on 2015-08-11T03:26:10Z : No. of bitstreams: 1 Publico-126.pdf: 520997 bytes, checksum: 85e8cbd8b81462d16c1e17d94e15990a (MD5) / Altos níveis de cortisol plasmático têm sido associados ao aumento de homocisteína. No presente estudo investigamos se a diminuição da concentração de cortisol, induzida pela administração aguda e oral de um benzodiazepínico, poderia diminuir níveis plasmáticos de homocisteína, e se tais mudanças seriam similares em ambos os gêneros. O estudo consistiu na administração de doses orais agudas de flunitrazepam e placebo, em 24 voluntários com idades entre 18 e 35 anos, saudáveis de ambos os sexos. Amostras de sangue foram coletadas após o pico plasmático da concentração de flunitrazepam. Diversos parâmetros bioquímicos foram analisados: homocisteína, cisteína, vitaminas B6 e B12, como também hormônios sexuais. O flunitrazepam diminuiu os níveis plasmáticos do cortisol, cisteína e homocisteína, independentemente do gênero. Não foram achadas correlações entre o cortisol e outros parâmetros bioquímicos. As concentrações plasmáticas de cisteína e homocisteína foram negativamente correlacionadas com concentrações plasmáticas de flunitrazepam, sugerindo que tais alterações nesses aminoácidos estariam relacionadas ao metabolismo desse benzodiazepínico. A administração aguda de flunitrazepam diminui níveis plasmáticos de homocisteína e cisteína por meio de mecanismos desconhecidos que não pareceram ter relação com as alterações plasmáticas de cortisol. Devido à importância da homocisteína como fator de risco de diversas doenças, tais mecanismos são alvos em potencial para a aplicação clínica. / Background: High cortisol plasma concentrations have been shown to be associated with increases in homocysteine. Here we studied whether decreases in cortisol, induced by an acute oral dose of a benzodiazepine, could decrease homocysteine, and if changes were similar in both genders. Methods: This was a double-blind, cross-over design study of acute oral doses of flunitrazepam and placebo in young, healthy, male and female volunteers. Blood samples were collected after peak-plasma concentration of flunitrazepam. Various biochemical parameters were analysed, such as homocysteine, cysteine, folate, vitamins B6 and B12, as well as male and female hormones. Results: flunitrazepam reduced cortisol, cysteine and homocysteine plasma concentrations, irrespective of gender. No correlations were found between cortisol and other biochemical markers. Plasma concentration of cysteine and homocysteine were negatively correlated with plasma flunitrazepam concentration, suggesting that changes in these amino acids were related to the metabolism of this benzodiazepine. Conclusion: Acute administration of flunitrazepam decreases plasma homocysteine and cysteine through as yet unknown mechanisms that do not seem related to changes in cortisol. Given the importance of homocysteine as a marker of life-threatening disorders, such mechanisms are potential targets for clinical application. / TEDE / BV UNIFESP: Teses e dissertações

The aim of this study was to carry out experiments with maize (Zea mays) for the purpose of finding out the efficiency of phytoextraction of chosen pharmaceuticals from the nutrient solution. The plants were cultivated for three weeks in a sterile environment. Then was added a nutrient solution enriched with chosen benzodiazepines - diazepam, flunitrazepam, nitrazepam and bromazepam - in concentration 5-10 mg/L. The samples from each plant were taken every day (24 hours) and then were analyzed with HPLC/UV. The efficiency of phytoextraction was evaluated in two ways. The first one as an percentage of a decrease of the concentration of the pharmaceuticals in the solution with time, the second one as an amount of phytoextracted pharmaceutical in milligrames per gram of the plant matter. From the standpoint of the decrease of the concentration was as the most efficient measured the phytoextraction of nitrazepam (74,7 %), less efficient diazepam and bromazepam (55,2 %, respectively 53,9 %) and the least efficient flunitrazepam (38,0 %). When converted to the mass of the plant matter the most efficient was found the phytoextraction of bromazepam (0,08 mg of drug to 1 gram of plant matter), lower efficiency by bromazepam and diazepam (both 0,02 mg) and the lowest again by flunitrazepam (0,01 mg). key...

Atualmente os benzodiazepínicos constituem o grupo de fármacos de prescrição mais consumidas em todo o mundo. Além da utilização desta classe farmacológica como fármacos de abuso, mais recentemente seu uso está associado a uma nova cultura psicodélica emergente. O termo \"club drugs\" tem sido usado para descrever estes fármacos que levam a efeitos psicodélicos e euforizantes. Acresça-se a isto à preocupante utilização destas substâncias em situações de estupro e/ou assalto, as chamadas \"drug-facilitated sexual assault\", destacando-se o flunitrazepam. Devido às pequenas doses administradas e a extensiva metabolização, a identificação do flunitrazepam e seus metabólitos torna-se dificultada em relação a outros benzodiazepínicos. O presente trabalho constitui validação de metodologia analítica que permita a correta identificação e quantificação de flunitrazepam e seu principal produto de biotransformação, o 7-aminoflunitrazepam, em soro. O método desenvolvido mostrou boa linearidade, precisão, exatidão, rendimento e capacidade de detectar os analitos mesmo em baixas concentrações, permitindo desta forma a inferência sobre a realidade dos casos onde se utiliza este fármaco sem fins terapêuticos. / Currently the benzodiazepines are one of the most consumed groups among the prescripton drugs in the world. Beside this, they have been used as drugs of abuse and more recently their use is associated with the new emerging psychodelic culture. The term \"club drugs\" has been used to describe these drugs that cause psychodelic and euphoric effects. In addition to this, there is a growing concern with the use of these substances related to \"drug-facilitated sexual assault\", among of which Flunitrazepan is pointed out as one of the most important . Due to the small doses involved in the consumption for this purpose and also the extense biotransformation, the identification of this analyte and its metabolites become more difficult than that of other benzodiazeines. This study provides an analytical validation method that enables correct identification and quantification of Flunitrazepam and its main biotransformation product, the 7-aminoflunitrazepam, in serum. The method developed demonstrates good linearity, precision, accuracy, recovery and capacity of detect the analytes, even in low concentration. Thus making possible to makes inferences regarding the reality of cases where it is used as a drug without therapeutic use.

Atualmente os benzodiazepínicos constituem o grupo de fármacos de prescrição mais consumidas em todo o mundo. Além da utilização desta classe farmacológica como fármacos de abuso, mais recentemente seu uso está associado a uma nova cultura psicodélica emergente. O termo \"club drugs\" tem sido usado para descrever estes fármacos que levam a efeitos psicodélicos e euforizantes. Acresça-se a isto à preocupante utilização destas substâncias em situações de estupro e/ou assalto, as chamadas \"drug-facilitated sexual assault\", destacando-se o flunitrazepam. Devido às pequenas doses administradas e a extensiva metabolização, a identificação do flunitrazepam e seus metabólitos torna-se dificultada em relação a outros benzodiazepínicos. O presente trabalho constitui validação de metodologia analítica que permita a correta identificação e quantificação de flunitrazepam e seu principal produto de biotransformação, o 7-aminoflunitrazepam, em soro. O método desenvolvido mostrou boa linearidade, precisão, exatidão, rendimento e capacidade de detectar os analitos mesmo em baixas concentrações, permitindo desta forma a inferência sobre a realidade dos casos onde se utiliza este fármaco sem fins terapêuticos. / Currently the benzodiazepines are one of the most consumed groups among the prescripton drugs in the world. Beside this, they have been used as drugs of abuse and more recently their use is associated with the new emerging psychodelic culture. The term \"club drugs\" has been used to describe these drugs that cause psychodelic and euphoric effects. In addition to this, there is a growing concern with the use of these substances related to \"drug-facilitated sexual assault\", among of which Flunitrazepan is pointed out as one of the most important . Due to the small doses involved in the consumption for this purpose and also the extense biotransformation, the identification of this analyte and its metabolites become more difficult than that of other benzodiazeines. This study provides an analytical validation method that enables correct identification and quantification of Flunitrazepam and its main biotransformation product, the 7-aminoflunitrazepam, in serum. The method developed demonstrates good linearity, precision, accuracy, recovery and capacity of detect the analytes, even in low concentration. Thus making possible to makes inferences regarding the reality of cases where it is used as a drug without therapeutic use.

Major depression and suicide are associated with altered concentrations of specific noradrenergic proteins in the human locus coeruleus (LC). Based on experimental studies that can reproduce these LC abnormalities in laboratory animals, we hypothesized that noradrenergic pathobiology in depression is a result of overactivity of the LC. LC activity is under the control of both excitatory and inhibitory inputs. A major inhibitory input to the LC is GABAergic, arising from the nucleus prepositus hypoglossi. Numerous studies demonstrating low levels of GABA in the CSF and plasma of subjects with major depressive disorder (MDD) raise the possibility that LC overactivity in depression may be secondary to reduced GABAergic input to the LC. Here, GABAergic input to the LC in depression was evaluated by studying the binding of [ H]flunitrazepam to GABA receptors at three anatomically defined levels of the human postmortem LC. LC tissues were collected from subjects with MDD, subjects with depressive disorders including MDD that died as a result of suicide, and psychiatrically normal control subjects. A modest rostral-caudal gradient of GABA receptor binding density was observed among all subjects. No significant differences in the amount of binding to GABA receptors were observed between control subjects (n = 21) and MDD subjects (n = 9) or depressed suicide victims (n = 17). These results demonstrate that GABA receptor binding in the LC measured with [ H]flunitrazepam is not altered in subjects with depressive illnesses.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Made available in DSpace on 2015-07-22T20:50:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-26. Added 1 bitstream(s) on 2015-08-11T03:25:54Z : No. of bitstreams: 1 Publico-11764a.pdf: 1760987 bytes, checksum: 26371946d909a5525c0bd6c7cc6d7c33 (MD5). Added 1 bitstream(s) on 2015-08-11T03:25:55Z : No. of bitstreams: 2 Publico-11764a.pdf: 1760987 bytes, checksum: 26371946d909a5525c0bd6c7cc6d7c33 (MD5) Publico-11764b.pdf: 969495 bytes, checksum: d87ae7194b036aaff67581e32d434f64 (MD5) / Objetivo: Verificar se indivíduos susceptíveis e não-susceptíveis às convulsões clônicas induzidas pelo DMCM, um agonista inverso benzodiazepínico, diferem: 1) na sensibilidade ao efeito hipnótico induzido pelo diazepam e por outros moduladores alostéricos positivos do receptor GABAA; 2) na marcação auto-radiográfica com o [3H]- flunitrazepam ao longo do encéfalo; 3) na marcação de [3H]-L-glutamato e do [3H]-MK 801 em membranas de regiões encefálicas; e 4) na atividade da enzima Na+/K+- ATPase, bem como na marcação da [3H]-ouabaína às isoenzimas Na+/K+- ATPase de alta e de baixa afinidade ao radioligante em membranas de regiões encefálicas. Métodos: Ratos Wistar, machos, adultos foram administrados intraperitonealmente duas vezes com uma DC50 de DMCM (com intervalo de uma semana entre as administrações), obtendo-se dois grupos distintos: o grupo susceptível às convulsões (SC), que apresentou convulsões clônicas em ambas as exposições à droga, e o grupo não-susceptível às convulsões (NSC), que não apresentou alterações motoras em ambas as exposições. Após cerca de 25 dias da segunda administração de DMCM, os grupos selecionados foram submetidos aos experimentos com os hipnóticos diazepam, pentobarbital e etanol, nos quais foram registrados o tempo e a latência de sono ou foram sacrificados e seus encéfalos retirados para os seguintes ensaios bioquímicos: 1) auto-radiografia com o [3H]-flunitrazepam; 2) marcação de [3H]-L-glutamato e de [3H]- MK 801 em membranas neuronais; e 3) atividade enzimática da Na+/K+- ATPase e marcação de [3H]-ouabaína em enzimas de alta e baixa afinidade em membranas neuronais. Resultados: O grupo SC apresentou menor tempo de sono induzido pelo diazepam com relação ao grupo NSC, embora não tenham se distinguindo no tempo de sono induzido pelo pentobarbital e pelo etanol. Com relação aos experimentos bioquímicos, observou-se uma menor marcação de [3H]-flunitrazepam na região CA2 ventral do hipocampo no grupo SC. Quanto à ligação de [3H]-L-glutamato foi menor no grupo SC nas regiões do córtex frontal, amígdala + córtex límbico e hipocampo, enquanto que a ligação de [3H]-MK 801 foi menor no córtex frontal, hipocampo e estriado. Embora os grupos não tenham se diferenciado na atividade enzimática da Na+/K+- ATPase, o grupo SC apresentou uma menor marcação da [3H]-ouabaína em isoenzimas de alta afinidade nas regiões do tronco encefálico, córtex frontal e hipocampo, bem como uma menor marcação de [3H]-ouabaína nas regiões do tronco encefálico e córtex frontal em isoenzimas de baixa afinidade. Conclusão: As diferenças entre os grupos quanto à sensibilidade ao efeito convulsivante do DMCM, à ansiedade observada em experimentos anteriores, bem como à sensibilidade ao efeito hipnótico do diazepam podem estar associadas a uma diferença nos sítios benzodiazepínicos da região CA2 ventral do hipocampo, na ix atividade glutamatérgica e em isoformas específicas da Na+/K+- ATPase em determinadas regiões encefálicas. / Objective: The aim of this work was to verify if rats susceptible and non-susceptible to clonic convulsions induced by DMCM, a benzodiazepine inverse agonist, differ: 1) in the sensitivity to the hypnotic effect induced by diazepam and by others positive allosteric modulators of GABAA receptors; 2) in auto-radiographical analysis of [3H]-flunitrazepam binding along the brain; 3) in the binding of [3H]-L-glutamate and of [3H]-MK 801 in membranes from discrete brain regions; and 4) in the Na+/K+-ATPase activity, as well as in the binding of [3H]-ouabain to Na+/K+-ATPase isoenzimes with high and low affinity to the radioligand in membranes from discrete brain regions. Methods: Adult, male, Wistar rats were administered with two intraperitoneal injections of a convulsant dose 50% (CD50) of DMCM (one-week interval between them), resulting in two distinct groups: the group susceptible to clonic convulsions (SC), which presented clonic convulsions in both the expositions to the drug, and the group nonsusceptible to clonic convulsions (NSC), which did not present any motor disturbance in both the expositions. After 25 days from the second exposition to DMCM, the selected groups were submitted to the experiments with the hypnotics diazepam, pentobarbital and ethanol, in which were registered the latency and the time of sleep or they were sacrified and their brains were removed to carry out the following assays: 1) autoradiography with [3H]-flunitrazepam; 2) binding with the [3H]-L-glutamate and with the [3H]-MK 801 in neuronal membranes; 3) enzymatic activity of Na+/K+-ATPase and binding of [3H]-ouabain to the isoenzimes with high and low affinity in neuronal membranes. Results: The SC group presented a lower sleeping time induced by diazepam compared to the NSC group, and did not differ in the sleeping time induced by pentobarbital and ethanol. Concearning the biochemical experiments, it was observed a lower binding of [3H]-flunitrazepam in the CA2 subregion of ventral hippocampus in the SC group. A lower binding of [3H]-L-glutamate was also observed in the SC group in the frontal cortex, amygdala plus limbic cortex and hippocampus, whereas the binding of [3H]-MK 801 was lower in the frontal cortex, hippocampus and striatum compared to the NSC group. Althougt the groups did not differ in the enzymatic activity of Na+/K+- ATPase, the SC group presented a lower binding of [3H]-ouabain to the high-affinity isoenzimes in the brainstem, frontal cortex and hippocampus, as well as a lower binding of [3H]-ouabain to the low-affinity isoenzimes in the brainstem and in the frontal cortex compared to the NSC group. Conclusion: The differences between the groups concerning the sensitivity to the convulsant effect of DMCM, the level of anxiety previously observed, as well as the sensitivity to the hypnotic effect of diazepam may be associated with the GABAA/benzodiazepine site in CA2 subregion of ventral hippocampus, with glutamatergic activity and with specific isoforms of Na+/K+-ATPase in rat brain regions. / TEDE / BV UNIFESP: Teses e dissertações

Drug facilitated assault (DFA) is an increasing problem in the UK. The crime often occurs through the surreptitious administration of a drug into a victims drink, rendering the victim unable to resist the assault. The detection of these drugs in a biological specimen from the victim is one of the most challenging facets of forensic chemistry. Drug concentrations can be very low, as often only a single dose is administered, and the pharmacodynamics of commonly employed drugs further hinders the testing process. The research presented in this work shows the development of several new assays for the detection of flunitrazepam, gamma-hydroxybutyrate (GHB) and ethyl glucuronide (EtG) in a variety of biological matrices. New methods of drug testing in blood and urine are demonstrated, as well as interesting developments in the field of hair testing. Using hair to detect drug exposure allows a much wider window of detection than the more traditional matrices of blood and urine. New methods are presented in this work using gas chromatography-tandem mass spectrometry (GCMS/MS) to detect drugs in hair. Validation data is presented along with the results of authentic DFA testing. All aspects of the drug testing procedure have been evaluated, from new extraction techniques utilising water instead of solvents, to novel clean up stages involving the unique combination of SFE and SPME. Several confirmation techniques are explored including single quadrupole, triple quadrupole and ion trap mass spectrometry. In addition to developing assays for DFA cases, the versatility of this type of analytical chemistry is explored in two population studies. The first study evaluates alcohol consumption between two groups; drugs users and non drug users in medico-legal cases. There is an anecdotal belief amongst drug clinic staff that alcohol use is lower in drugs users than it is in non drug users. This study presents the first scientific confirmation of this belief through EtG (an alcohol metabolite) testing in hair of the two groups. The second study investigates whether there is a correlation between EtG and cocaethylene (a metabolite of cocaine only produced in the presence of alcohol) in cocaine users. Results f this study suggest that there is no positive correlation between the two compounds. The research presented in this thesis aims to further the analytical science surrounding FA investigation and provide accurate, sensitive and reliable methodology for drug esting in blood, urine and hair.