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1.
Huan Jing Ke Xue ; 43(1): 230-238, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989507

RESUMO

Based on the flow direction of the Fuhe River into Baiyangdian Lake, the impacted area of the Fuhe River was divided into 6 subareas, and sediments from 48 sites were collected in November 2020. The characteristics and risks of sediment nutrients and heavy metal pollution in these six subareas were investigated. The results showed that the average ω(TN), ω(TP), and ω(TOC) were 1841 mg·kg-1, 769 mg·kg-1, and 1.77%, respectively. The major heavy metals were Cd, Cu, Zn, Hg, and Pb, which were 3.73, 1.50, 1.42, 1.31, and 1.31 times the soil background values for Hebei Province, respectively. The TP and heavy metal (Cd, Cu, Zn, Hg, and Pb) content showed a decreasing trend from the Fuhe River estuary to the downstream Zaolinzhuang, whereas the TN and TOC content showed no marked trends. TN, TP, TOC, and heavy metals (Cd, Cu, Zn, Hg, and Pb) were enriched in surface sediments (0-10 cm). The TP content in the surface sediments (0-10 cm) of the Fuhe River estuary, Fuhe River estuary-Nanliuzhuang, and Nanliuzhuang subareas were heavily polluted; the Wangjiazhai and Guangdian subareas were moderately polluted; and the Zaolinzhuang subarea was slightly polluted. Cd and Hg were the major contributors to heavy metal pollution, which were at considerable risk and moderate risk levels, respectively. The heavy metals in surface sediments (0-10 cm) of the Fuhe River estuary, Fuhe River estuary-Nanliuzhuang, and Nanliuzhuang subareas were at a considerable risk level, and the sediments below 30 cm presented a low risk level. The leaching concentrations of heavy metals in sediments from the subarea of severe ecological risk level were far less than the identification standard values of leaching toxicity, suggesting that the sediments can be treated as general waste after dredging.


Assuntos
Metais Pesados , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Metais Pesados/análise , Nutrientes , Medição de Risco , Poluentes Químicos da Água/análise
2.
Huan Jing Ke Xue ; 42(11): 5303-5311, 2021 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-34708969

RESUMO

A total of 22 antibiotics and 16 polycyclic aromatic hydrocarbons(PAHs) in sediments before and after desilting in typical areas(fish ponds and open water) of Baiyangdian Lake were analyzed using HPLC-MS/MS and GC/MS(high performance liquid chromatography and gas chromatography coupled with mass spectrometry), to evaluate their potentially risks to the ecological environment. The results showed that the contents of 22 antibiotics in Baiyangdian Lake sediments ranged from 0 to 52.89 ng·g-1, in which the quinolones content was the highest. After dredging treatment, the average content of antibiotics in Nanliuzhuang open water area decreased from 46.25 ng·g-1 to 9 ng·g-1(80.54% reduction), while the average content of antibiotic(19.07 ng·g-1) in Caiputai remained relatively stable. Therefore, the dredging treatment performed better in removing antibiotics from Naliuzhuang area. The total contents of 16 PAHs in sediments ranged from 23.79 ng·g-1 to 329.40 ng·g-1, in which Naphthalene was the highest(242.02 ng·g-1), while Fluoranthene was the lowest. The average content of PAHs in sediments in Nanliuzhuang decreased from 117.45 ng·g-1 to 50.49 ng·g-1 after dredging, while PAHs in Caiputai(57.98 ng·g-1) remained stable; the 57.01% reduction in PAHs in Nanliuzhuang open water indicated that dredging treatment exhibited stronger effects on PAHs variations in Nanliuzhuang compared to that of Caiputai. In addition, the ecological risk assessment showed that the risk of Enrofloxacin and Norfloxacin was high in area S2 of Nanliuzhuang open water, while PAHs exhibited relatively low ecological risk, in which the Naphthalene in area S1 of Fuhe river posed medium ecological risk while the remaining produced low ecological risks. The results indicated that quinolone antibiotics in sediments of the un-dredged area of Baiyangdian Lake should be monitored due to its higher ecological risk.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Antibacterianos , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Sedimentos Geológicos , Lagos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
3.
Huan Jing Ke Xue ; 42(10): 4781-4788, 2021 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-34581120

RESUMO

A dredging demonstration project in the Baiyangdian Lake included open waters and fishing ponds to reduce the internal release of nitrogen and phosphorus from bottom sediments. The dredging depth design was determined by both the sediment vertical distribution profile of total nitrogen and phosphorus, and the sediment adsorption-desorption equilibrium method. The determined dredging depths were very similar and coincident. The dredging depth for the demonstration area of open waters in Nanliuzhuang was identified as(50±10) cm; and the dredging depths for fishing ponds were(30±10) cm in both the Nanliuzhuang and Caiputai demonstration areas. The equilibrium nitrogen(NH4+-N) and phosphorus(SRP) concentrations at zero net sorption or desorption(ENC0 and EPC0) were significantly positively correlated with both exchangeable and total nitrogen and phosphorus in the sediments. The total nitrogen and phosphorus in the sediments were also used to predict the risk of their release from the bottom sediments to the overlying water column. The sediment layers with ENC0 and EPC0 values greater than the NH4+-N and SRP in the overlying water column indicated the sediments act as a source of dissolved nitrogen and phosphorus to the overlying water column in the Nanliuzhuang and Caiputai demonstration areas. Accordingly, the sediment layers with both total nitrogen concentrations greater than 750 mg·kg-1 and total phosphorus concentrations greater than 500 mg·kg-1 should be identified as dredging layers.


Assuntos
Fósforo , Poluentes Químicos da Água , Adsorção , China , Sedimentos Geológicos , Lagos , Nitrogênio/análise , Fósforo/análise , Poluentes Químicos da Água/análise
4.
Environ Sci Technol ; 50(6): 3111-8, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26862886

RESUMO

The pyrolysis treatment with biomass is a promising technology for the remediation of chromite-ore-processing residue (COPR). However, the mechanism of this process is still unclear. In this study, the behavior of pyrolysis reduction of Cr(VI) by cellulose, the main component of biomass, was elucidated. The results showed that the volatile fraction (VF) of cellulose, ie. gas and tar, was responsible for Cr(VI) reduction. All organic compounds, as well as CO and H2 in VF, potentially reduced Cr(VI). X-ray absorption near-edge structure (XANES) spectroscopy and extended X-ray absorption fine-structure (EXAFS) spectroscopy confirmed the reduction of Cr(VI) to Cr(III) and the formation of amorphous Cr2O3. The remnant Cr(VI) content in COPR can be reduced below the detection limit (2 mg/kg) by the reduction of COPR particle and extension of reaction time between VF and COPR. This study provided a deep insight on the co-pyrolysis of cellulose with Cr(VI) in COPR and an ideal approach by which to characterize and optimize the pyrolysis treatment for COPR by other organics.


Assuntos
Celulose/química , Cromo/química , Resíduos Industriais , Metalurgia/métodos , Biomassa , Oxirredução , Espectroscopia por Absorção de Raios X
5.
J Pharmacol Exp Ther ; 338(1): 345-52, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21508084

RESUMO

Metabotropic glutamate receptor 7 (mGluR7) remains the most elusive of the eight known mGluRs primarily because of the limited availability of tool compounds to interrogate its potential therapeutic utility. The discovery of N,N'-dibenzhydrylethane-1,2-diamine dihydrochloride (AMN082) as the first orally active, brain-penetrable, mGluR7-selective allosteric agonist by Mitsukawa and colleagues (Proc Natl Acad Sci USA 102:18712-18717, 2005) provides a means to investigate this receptor system directly. AMN082 demonstrates mGluR7 agonist activity in vitro and interestingly has a behavioral profile that supports utility across a broad spectrum of psychiatric disorders including anxiety and depression. The present studies were conducted to extend the in vitro and in vivo characterization of AMN082 by evaluating its pharmacokinetic and metabolite profile. Profiling of AMN082 in rat liver microsomes revealed rapid metabolism (t(1/2) < 1 min) to a major metabolite, N-benzhydrylethane-1,2-diamine (Met-1). In vitro selectivity profiling of Met-1 demonstrated physiologically relevant transporter binding affinity at serotonin transporter (SERT), dopamine transporter (DAT), and norepinephrine transporter (NET) (323, 3020, and 3410 nM, respectively); whereas the parent compound AMN082 had appreciable affinity at NET (1385 nM). AMN082 produced antidepressant-like activity and receptor occupancy at SERT up to 4 h postdose, a time point at which AMN082 is significantly reduced in brain and plasma while the concentration of Met-1 continues to increase in brain. Acute Met-1 administration produced antidepressant-like activity as would be expected from its in vitro profile as a mixed SERT, NET, DAT inhibitor. Taken together, these data suggest that the reported in vivo actions of AMN082 should be interpreted with caution, because they may involve other mechanisms in addition to mGluR7.


Assuntos
Compostos Benzidrílicos/farmacologia , Monoaminas Biogênicas/farmacologia , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/fisiologia , Regulação Alostérica/efeitos dos fármacos , Regulação Alostérica/fisiologia , Animais , Compostos Benzidrílicos/metabolismo , Monoaminas Biogênicas/fisiologia , Células CHO , Cricetinae , Cricetulus , Células HEK293 , Humanos , Masculino , Camundongos , Ligação Proteica/fisiologia , Ratos , Ratos Sprague-Dawley
6.
J Med Chem ; 53(21): 7639-46, 2010 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-20932009

RESUMO

As part of our efforts to develop agents for CNS diseases, we have been focused on the 5-HT(6) receptor in order to identify potent and selective ligands for cognitive enhancement. Herein we report the identification of a novel series of 5-piperazinyl-3-sulfonylindazoles as potent and selective 5-HT(6) antagonists. The synthesis, SAR, and pharmacokinetic and pharmacological activities of some of the compounds including 3-(naphthalen-1-ylsulfonyl)-5-(piperazin-1-yl)-1H-indazole (WAY-255315 or SAM-315) will be described.


Assuntos
Indazóis/síntese química , Nootrópicos/síntese química , Piperazinas/síntese química , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/síntese química , Sulfonas/síntese química , Acetilcolina/metabolismo , Animais , Disponibilidade Biológica , Encéfalo/metabolismo , Ácido Glutâmico/metabolismo , Células HeLa , Humanos , Indazóis/farmacocinética , Indazóis/farmacologia , Ligantes , Nootrópicos/farmacocinética , Nootrópicos/farmacologia , Piperazinas/farmacocinética , Piperazinas/farmacologia , Ratos , Antagonistas da Serotonina/farmacocinética , Antagonistas da Serotonina/farmacologia , Relação Estrutura-Atividade , Sulfonas/farmacocinética , Sulfonas/farmacologia
7.
Mol Pharmacol ; 78(6): 996-1003, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20855465

RESUMO

Endocannabinoids are lipid molecules that serve as natural ligands for the cannabinoid receptors CB1 and CB2. They modulate a diverse set of physiological processes such as pain, cognition, appetite, and emotional states, and their levels and functions are tightly regulated by enzymatic biosynthesis and degradation. 2-Arachidonoylglycerol (2-AG) is the most abundant endocannabinoid in the brain and is believed to be hydrolyzed primarily by the serine hydrolase monoacylglycerol lipase (MAGL). Although 2-AG binds and activates cannabinoid receptors in vitro, when administered in vivo, it induces only transient cannabimimetic effects as a result of its rapid catabolism. Here we show using a mouse model with a targeted disruption of the MAGL gene that MAGL is the major modulator of 2-AG hydrolysis in vivo. Mice lacking MAGL exhibit dramatically reduced 2-AG hydrolase activity and highly elevated 2-AG levels in the nervous system. A lack of MAGL activity and subsequent long-term elevation of 2-AG levels lead to desensitization of brain CB1 receptors with a significant reduction of cannabimimetic effects of CB1 agonists. Also consistent with CB1 desensitization, MAGL-deficient mice do not show alterations in neuropathic and inflammatory pain sensitivity. These findings provide the first genetic in vivo evidence that MAGL is the major regulator of 2-AG levels and signaling and reveal a pivotal role for 2-AG in modulating CB1 receptor sensitization and endocannabinoid tone.


Assuntos
Moduladores de Receptores de Canabinoides/fisiologia , Endocanabinoides , Monoacilglicerol Lipases/metabolismo , Receptor CB1 de Canabinoide/fisiologia , Animais , Ativação Enzimática/genética , Ativação Enzimática/fisiologia , Hidrólise , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Monoacilglicerol Lipases/deficiência , Monoacilglicerol Lipases/fisiologia , Medição da Dor/métodos
8.
J Med Chem ; 53(10): 4066-84, 2010 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-20443629

RESUMO

As part of an effort to identify 5-HT(1A) antagonists that did not possess typical arylalkylamine or keto/amido-alkyl aryl piperazine scaffolds, prototype compound 10a was identified from earlier work in a combined 5-HT(1A) antagonist/SSRI program. This quinolyl-piperazinyl piperidine analogue displayed potent, selective 5-HT(1A) antagonism but suffered from poor oxidative metabolic stability, resulting in low exposure following oral administration. SAR studies, driven primarily by in vitro liver microsomal stability assessment, identified compound 10b, which displayed improved oral bioavailability and lower intrinsic clearance. Further changes to the scaffold (e.g., 10r) resulted in a loss in potency. Compound 10b displayed cognitive enhancing effects in a number of animal models of learning and memory, enhanced the antidepressant-like effects of the SSRI fluoxetine, and reversed the sexual dysfunction induced by chronic fluoxetine treatment.


Assuntos
Piperazinas/síntese química , Piperidinas/síntese química , Quinolinas/síntese química , Antagonistas do Receptor 5-HT1 de Serotonina , Acetilcolina/metabolismo , Administração Oral , Precursor de Proteína beta-Amiloide/genética , Animais , Antidepressivos/síntese química , Antidepressivos/química , Antidepressivos/farmacologia , Disponibilidade Biológica , Células CHO , Córtex Cerebral/metabolismo , Cognição/efeitos dos fármacos , Cricetinae , Cricetulus , Fluoxetina/farmacologia , Hipocampo/metabolismo , Técnicas In Vitro , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Microssomos Hepáticos/metabolismo , Nootrópicos/síntese química , Nootrópicos/química , Nootrópicos/farmacologia , Ereção Peniana/efeitos dos fármacos , Piperazinas/química , Piperazinas/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Quinolinas/química , Quinolinas/farmacologia , Ratos , Serotonina/metabolismo , Relação Estrutura-Atividade
9.
J Neurosci ; 30(6): 2017-24, 2010 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-20147530

RESUMO

Endocannabinoids (eCBs) function as retrograde signaling molecules at synapses throughout the brain, regulate axonal growth and guidance during development, and drive adult neurogenesis. There remains a lack of genetic evidence as to the identity of the enzyme(s) responsible for the synthesis of eCBs in the brain. Diacylglycerol lipase-alpha (DAGLalpha) and -beta (DAGLbeta) synthesize 2-arachidonoyl-glycerol (2-AG), the most abundant eCB in the brain. However, their respective contribution to this and to eCB signaling has not been tested. In the present study, we show approximately 80% reductions in 2-AG levels in the brain and spinal cord in DAGLalpha(-/-) mice and a 50% reduction in the brain in DAGLbeta(-/-) mice. In contrast, DAGLbeta plays a more important role than DAGLalpha in regulating 2-AG levels in the liver, with a 90% reduction seen in DAGLbeta(-/-) mice. Levels of arachidonic acid decrease in parallel with 2-AG, suggesting that DAGL activity controls the steady-state levels of both lipids. In the hippocampus, the postsynaptic release of an eCB results in the transient suppression of GABA-mediated transmission at inhibitory synapses; we now show that this form of synaptic plasticity is completely lost in DAGLalpha(-/-) animals and relatively unaffected in DAGLbeta(-/-) animals. Finally, we show that the control of adult neurogenesis in the hippocampus and subventricular zone is compromised in the DAGLalpha(-/-) and/or DAGLbeta(-/-) mice. These findings provide the first evidence that DAGLalpha is the major biosynthetic enzyme for 2-AG in the nervous system and reveal an essential role for this enzyme in regulating retrograde synaptic plasticity and adult neurogenesis.


Assuntos
Encéfalo/metabolismo , Moduladores de Receptores de Canabinoides/fisiologia , Endocanabinoides , Lipase Lipoproteica/genética , Animais , Ácidos Araquidônicos/metabolismo , Encéfalo/citologia , Glicerídeos/metabolismo , Hipocampo/citologia , Hipocampo/metabolismo , Fígado/metabolismo , Camundongos , Camundongos Knockout , Neurogênese , Plasticidade Neuronal , Transdução de Sinais , Medula Espinal/metabolismo , Sinapses/fisiologia
10.
Int J Neuropsychopharmacol ; 13(9): 1193-205, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20047711

RESUMO

Biogenic amines such as norepinephrine, dopamine, and serotonin play a well-described role in the treatment of mood disorders and some types of pain. As alpha2A-adrenoceptors regulate the release of these neurotransmitters, we examined the therapeutic potential of BRL 44408, a potent (Ki=8.5 nM) and selective (>50-fold) alpha2A-adrenoceptor antagonist (K(B)=7.9 nM). In rats, BRL 44408 penetrated the central nervous system resulting in peak brain and plasma concentrations of 586 ng/g and 1124 ng/ml, respectively. In a pharmacodynamic assay, pretreatment with BRL 44408 to rats responding under a fixed-ratio 30 operant response paradigm resulted in a rightward shift of the clonidine dose-response curve, an effect indicative of alpha2-adrenoceptor antagonism in vivo. Consistent with presynaptic autoreceptor antagonism and tonic regulation of neurotransmitter release, acute administration of BRL 44408 elevated extracellular concentrations of norepinephrine and dopamine, but not serotonin, in the medial prefrontal cortex. Additionally, BRL 44408, probably by inhibiting alpha2A heteroceptors, produced a significant increase in cortical levels of acetylcholine. In the forced swim test and schedule-induced polydipsia assay, BRL 44408 produced an antidepressant-like response by dose-dependently decreasing immobility time and adjunctive water intake, respectively, while in a model of visceral pain, BRL 44408 exhibited analgesic activity by decreasing para-phenylquinone (PPQ)-induced abdominal stretching. Finally, BRL 44408 did not produce deficits in overall motor coordination nor alter general locomotor activity. This preclinical characterization of the neurochemical and behavioural profile of BRL 44408 suggests that selective antagonism of alpha2A-adrenoceptors may represent an effective treatment strategy for mood disorders and visceral pain.


Assuntos
Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Analgésicos/farmacologia , Antidepressivos/farmacologia , Depressão/tratamento farmacológico , Imidazóis/farmacologia , Isoindóis/farmacologia , Receptores Adrenérgicos alfa 2/metabolismo , Antagonistas de Receptores Adrenérgicos alfa 2/farmacocinética , Analgésicos/farmacocinética , Animais , Antidepressivos/farmacocinética , Monoaminas Biogênicas/metabolismo , Encéfalo/metabolismo , Células CHO , Cricetinae , Cricetulus , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Imidazóis/farmacocinética , Isoindóis/farmacocinética , Masculino , Camundongos , Microdiálise , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Natação , Sede/efeitos dos fármacos
11.
J Mass Spectrom ; 45(2): 167-77, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19950120

RESUMO

Endocannabinoids (ECs), such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG), modulate a number of physiological processes, including pain, appetite and emotional state. Levels of ECs are tightly controlled by enzymatic biosynthesis and degradation in vivo. However, there is limited knowledge about the enzymes that terminate signaling of the major brain EC, 2-AG. Identification and quantification of 2-AG, 1-AG and arachidonic acid (AA) is important for studying the enzymatic hydrolysis of 2-AG. We have developed a sensitive and specific quantification method for simultaneous determination of 2-AG, 1-AG and AA from mouse brain and adipose tissues by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using a simple brain sample preparation method. The separations were carried out based on reversed phase chromatography. Optimization of electrospray ionization conditions established the limits of detection (S/N = 3) at 50, 25 and 65 fmol for 2-AG, 1-AG and AA, respectively. The methods were selective, precise (%R.S.D. < 10%) and sensitive over a range of 0.02-20, 0.01-10 and 0.05-50 ng/mg tissue for 2-AG, 1-AG and AA, respectively. The quantification method was validated with consideration of the matrix effects and the mass spectrometry (MS) responses of the analytes and the deuterium labeled internal standard (IS). The developed methods were applied to study the hydrolysis of 2-AG from mouse brain extracts containing membrane bound monoacylglycerol lipase (MAGL), and to measure the basal levels of 2-AG, 1-AG and AA in mouse brain and adipose tissues.


Assuntos
Ácido Araquidônico/análise , Ácidos Araquidônicos/análise , Química Encefálica , Cromatografia de Fase Reversa/métodos , Glicerídeos/análise , Espectrometria de Massas em Tandem/métodos , Tecido Adiposo/química , Animais , Cromatografia de Fase Reversa/economia , Endocanabinoides , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem/economia
12.
Bioorg Med Chem Lett ; 19(19): 5799-802, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19703774

RESUMO

We previously reported that a 3-pyridinecarbonitrile analog with a furan substituent at C-5 and a 4-methylindol-5-ylamino substituent at C-4, 1, was a potent inhibitor of PKCtheta (IC50=4.5 nM). Replacement of the C-5 furan ring of 1 with bicyclic heteroaryl rings, led to compounds with significantly improved potency against PKCtheta. Analog 6b with a 4-methylindol-5-ylamino group at C-4 and a 5-[(4-methylpiperazin-1-yl)methyl]-1-benzofuran-2-yl group at C-5 had an IC50 value of 0.28 nM for the inhibition of PKCtheta.


Assuntos
Aminopiridinas/química , Isoenzimas/antagonistas & inibidores , Nitrilas/química , Proteína Quinase C/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Piridinas/química , Aminopiridinas/síntese química , Aminopiridinas/farmacologia , Animais , Benzofuranos/síntese química , Benzofuranos/química , Benzofuranos/farmacologia , Meia-Vida , Humanos , Interleucina-2/metabolismo , Isoenzimas/metabolismo , Camundongos , Microssomos Hepáticos/metabolismo , Nitrilas/síntese química , Nitrilas/farmacologia , Proteína Quinase C/metabolismo , Proteína Quinase C-theta , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Piridinas/síntese química , Piridinas/farmacologia , Ratos , Linfócitos T/imunologia , Linfócitos T/metabolismo
13.
Artigo em Inglês | MEDLINE | ID: mdl-18824419

RESUMO

The systemic administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to mice produces a reliable and selective degeneration of the nigrostriatal pathway, a hallmark feature of Parkinson's disease (PD). Determining the brain concentrations of 1-methyl-4-phenyl pyridium (MPP+), the neurotoxic metabolite of MPTP, is critical for evaluating drugs designed to potentially treat PD. We have developed sensitive and specific quantitative methods for the determination of MPP+ in mouse striatal tissue by liquid chromatography/tandem mass spectrometry. The separations were carried out based on reversed phase chromatography or cation exchange chromatography with volatile elution buffer. Neutralizing the brain sample with 0.2M phosphate buffer successfully solved a high-performance liquid chromatography (HPLC) peak tailing of MPP+ in brain extracts with 0.4M perchloric acid (HClO4) under the reversed phase HPLC conditions, which significantly improved the sensitivity of the method. The HPLC peak shape of MPP+ using cation exchange chromatography was not affected by the pH of the samples. Optimization of electrospray ionization (ESI) conditions for the quaternary ammonium compound MPP+ established the limits of detection (LOD) (S/N=3) at 0.34pg/mg tissue and 0.007pg/mg tissue (5microl of injection) using the reversed phase liquid chromatography/tandem mass spectrometry (LC/MS/MS) and the cation exchange LC/MS/MS, respectively. Both methods were selective, precise (%R.S.D.<6%), and sensitive over a range of 0.001-1ng/mg tissue. The cation exchange method showed greater sensitivity and tolerance to low pH samples than the reversed phase method. The developed methods were applied to monitoring changes in MPP+ concentrations in vivo. Two reference agents, R-(-) Deprenyl and MK-801, known to alter the concentration of MPP+ in MPTP treated mice were evaluated.


Assuntos
1-Metil-4-fenilpiridínio/análise , Cromatografia Líquida/métodos , Corpo Estriado/metabolismo , Espectrometria de Massas em Tandem/métodos , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/administração & dosagem , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/metabolismo , 1-Metil-4-fenilpiridínio/metabolismo , Animais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Reprodutibilidade dos Testes
14.
Neurobiol Dis ; 31(3): 334-41, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18606547

RESUMO

The diuretic amiloride has recently proven neuroprotective in models of cerebral ischemia, a property attributable to the drug's inhibition of central acid-sensing ion channels (ASICs). Given that Parkinson's disease (PD), like ischemia, is associated with cerebral lactic acidosis, we tested amiloride in the MPTP-treated mouse, a model of PD also manifesting lactic acidosis. Amiloride was found to protect substantia nigra (SNc) neurons from MPTP-induced degeneration, as determined by attenuated reductions in striatal tyrosine hydroxylase (TH) and dopamine transporter (DAT) immunohistochemistry, as well as smaller declines in striatal DAT radioligand binding and dopamine levels. More significantly, amiloride also preserved dopaminergic cell bodies in the SNc. Administration of psalmotoxin venom (PcTX), an ASIC1a blocker, resulted in a much more modest effect, attenuating only the deficits in striatal DAT binding and dopamine. These findings represent the first experimental evidence of a potential role for ASICs in the pathogenesis of Parkinson's disease.


Assuntos
Acidose Láctica/tratamento farmacológico , Amilorida/farmacologia , Fármacos Neuroprotetores/farmacologia , Transtornos Parkinsonianos/tratamento farmacológico , Substância Negra/efeitos dos fármacos , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Canais Iônicos Sensíveis a Ácido , Acidose Láctica/etiologia , Acidose Láctica/fisiopatologia , Animais , Antiparkinsonianos/farmacologia , Ligação Competitiva/efeitos dos fármacos , Ligação Competitiva/fisiologia , Modelos Animais de Doenças , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/metabolismo , Peptídeos , Ensaio Radioligante , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/metabolismo , Venenos de Aranha/farmacologia , Substância Negra/metabolismo , Substância Negra/fisiopatologia , Tirosina 3-Mono-Oxigenase/metabolismo
15.
J Pharmacol Exp Ther ; 325(1): 134-45, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18182558

RESUMO

5-Hydroxytryptamine (5-HT)(1A) receptors play an important role in multiple cognitive processes, and compelling evidence suggests that 5-HT(1A) antagonists can reverse cognitive impairment. We have examined the therapeutic potential of a potent (K(i) = 1.1 nM), selective (>100-fold), orally bioavailable, silent 5-HT(1A) receptor antagonist (K(B) = 1.3 nM) (R)-N-(2-methyl-(4-indolyl-1-piperazinyl)-ethyl)-N-(2-pyridinyl)-cyclohexane carboxamide (WAY-101405). Oral administration of WAY-101405 was shown to be effective in multiple rodent models of learning and memory. In a novel object recognition paradigm, 1 mg/kg enhanced retention (memory) for previously learned information, and it was able to reverse the memory deficits induced by scopolamine. WAY-101405 (1 mg/kg) was also able to reverse scopolamine-induced deficits in a rat contextual fear conditioning model. In the Morris water maze, WAY-101405 (3 mg/kg) significantly improved learning in a paradigm of increasing task difficulty. In vivo microdialysis studies in the dorsal hippocampus of freely moving adult rats demonstrated that acute administration of WAY-101405 (10 mg/kg) increased extracellular acetylcholine levels. The selective radioligand [(3)H]WAY-100635, administered i.v., was used for in vivo receptor occupancy studies, where WAY-101405 occupied 5-HT(1A) receptors in the rat cortex, with an ED(50) value of 0.1 mg/kg p.o. Taken together, these studies demonstrate that WAY-101405 is a potent and selective, brain penetrant, orally bioavailable 5-HT(1A) receptor "silent" antagonist that is effective in preclinical memory paradigms at doses where approximately 90% of the postsynaptic 5-HT(1A) receptors are occupied. These results further support the rationale for use of this compound class in the treatment of cognitive dysfunction associated with psychiatric and neurological conditions.


Assuntos
Aminopiridinas/farmacologia , Cognição/efeitos dos fármacos , Cicloexanos/farmacologia , Piperazinas/farmacologia , Antagonistas do Receptor 5-HT1 de Serotonina , Antagonistas da Serotonina/farmacologia , Animais , Disponibilidade Biológica , Encéfalo/metabolismo , Memória/efeitos dos fármacos , Modelos Animais , Ensaio Radioligante , Ratos , Antagonistas da Serotonina/administração & dosagem , Antagonistas da Serotonina/farmacocinética
16.
Chirality ; 19(9): 658-82, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17390370

RESUMO

The application of Chiral Technology, or the (extensive) use of techniques or tools for the determination of absolute stereochemistry and the enantiomeric or chiral separation of racemic small molecule potential lead compounds, has been critical to successfully discovering and developing chiral drugs in the pharmaceutical industry. This has been due to the rapid increase over the past 10-15 years in potential drug candidates containing one or more asymmetric centers. Based on the experiences of one pharmaceutical company, a summary of the establishment of a Chiral Technology toolbox, including the implementation of known tools as well as the design, development, and implementation of new Chiral Technology tools, is provided.


Assuntos
Química Farmacêutica/métodos , Indústria Farmacêutica/métodos , Estereoisomerismo , Cromatografia/métodos , Dicroísmo Circular , Desenho de Fármacos , Elétrons , Humanos , Espectroscopia de Ressonância Magnética/métodos , Modelos Químicos , Conformação Molecular , Sais/farmacologia , Tecnologia Farmacêutica/métodos
17.
J Pharm Biomed Anal ; 44(2): 586-93, 2007 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-17383138

RESUMO

Monitoring concentrations of acetylcholine (ACh) in specific brain regions is important in understanding disease pathology, as well as in designing and evaluating novel disease-modifying treatments where cholinergic dysfunction is a hallmark feature. We have developed a sensitive and quantitative liquid chromatography/tandem mass spectrometry method to analyze the extracellular concentrations of ACh, choline (Ch) and (3-carboxylpropyl)-trimethylammonium (iso-ACh) in brain microdialysis samples of freely moving animals. One immediate advantage of this new method is the ability to monitor ACh in its free form without having to use a cholinesterase inhibitor in the perfusate. The separation of ACh, Ch, iso-ACh and related endogenous compounds was carried out based on cation exchange chromatography with a volatile elution buffer consisting of ammonium formate, ammonium acetate and acetonitrile. An unknown interference of ACh, which was observed in brain microdialysates from many studies, was well separated from ACh to ensure the accuracy of the measurement. Optimization of electrospray ionization conditions for these quaternary ammonium compounds achieved the limits of detection (S/N=3) of 0.2 fmol for ACh, 2 fmol for Ch and 0.6 fmol for iso-ACh using a benchtop tandem quadrupole mass spectrometer with moderate sensitivity. The limit of quantitation (S/N=10) was 1 fmol for ACh, 3 fmol for iso-ACh and 10 fmol for Ch. This method was selective, precise (<10% R.S.D.), and sensitive over a range of 0.05-10nM for ACh, 0.25-50 nM for iso-ACh and 15-3000 nM for Ch. To demonstrate that the developed method can be applied to monitoring changes in ACh concentrations in vivo, reference agents that have previously been shown to influence ACh levels were studied in rat dorsal hippocampus. This includes the 5-HT6 receptor antagonist, SB-271046, and the cholinesterase inhibitor, donepezil. Moreover, levels of ACh were demonstrated to be sensitive to infusion of tetrodotoxin (TTX) suggesting that the ACh being measured in vivo was of neuronal origin. Collectively, these biological data provided in vivo validation of this analytical method.


Assuntos
Acetilcolina/análise , Química Encefálica , Neurotransmissores/análise , Animais , Inibidores da Colinesterase/farmacologia , Cromatografia Líquida de Alta Pressão , Interpretação Estatística de Dados , Donepezila , Hipocampo/química , Hipocampo/metabolismo , Indanos/farmacologia , Indicadores e Reagentes , Masculino , Microdiálise , Piperidinas/farmacologia , Ratos , Receptores de Serotonina/efeitos dos fármacos , Padrões de Referência , Reprodutibilidade dos Testes , Antagonistas da Serotonina/farmacologia , Bloqueadores dos Canais de Sódio/farmacologia , Espectrometria de Massas por Ionização por Electrospray , Técnicas Estereotáxicas , Sulfonamidas/farmacologia , Tetrodotoxina/farmacologia , Tiofenos/farmacologia
18.
J Pharm Biomed Anal ; 40(3): 492-9, 2006 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-16125893

RESUMO

During the last three decades, a great deal of information has been discovered about chemical neurotransmission. However, the most important processes, namely the complex nature of neuronal circuitry, the "cross talk" between multiple neurotransmitter systems, and the varying effects neurochemicals have at different receptors, are still being explored. Techniques such as microdialysis are routinely employed to measure neurotransmitter levels in living tissue systems. Moreover, microdialysis studies have proven to be valuable in the investigation of neurodegenerative and psychiatric disease pathology, as well as in identifying novel drugs to treat such disorders. One particular challenge in performing these experiments is the requirement to couple microdialysis to sophisticated analytical equipment. Recently, considerable attention has been focused on the development of chromatographic-mass spectrometric techniques to provide more sensitive and accurate measurements of neurochemicals collected from in vivo microdialysis experiments. This review will provide a brief overview of the microdialysis technique, as well as how microdialysis and chromatography-mass spectrometry are being used to measure extracellular levels of neurotransmitters. The primary emphasis of this review will be on how these applications are used to measure levels of acetylcholine (ACh), dopamine, norepinephrine and gamma-aminobutyric acid (GABA).


Assuntos
Química Encefálica , Líquido Extracelular/química , Neurotransmissores/análise , Animais , Humanos , Espectrometria de Massas , Microdiálise
19.
Comb Chem High Throughput Screen ; 8(6): 459-66, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16178805

RESUMO

Integrity profiling of HTS hits is valuable for verification of the hit identity and purity. This provides early discovery researchers with more confident SAR theories. Methodology for integrity profiling of HTS hits must be high throughput, consume little material, and selectively provide structure-based data. Analytical techniques that can be utilized for integrity profiling methods are reviewed for their appropriateness in sample preparation, component separation, detection, purity quantitation, identity confirmation, and follow-up.


Assuntos
Cromatografia Líquida/métodos , Técnicas de Química Combinatória , Espectrometria de Massas/métodos , Espalhamento de Radiação , Espectrofotometria Ultravioleta , Relação Estrutura-Atividade
20.
J Mass Spectrom ; 40(8): 1017-29, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15934027

RESUMO

The use of a hybrid triple quadrupole-linear ion trap (QqQ(LIT)) mass spectrometer system for a comprehensive study of fragmentation mechanisms is described. The anxiolytic drug, buspirone, was chosen as a model compound for this study. With the advent of a QqQ(LIT) instrument, both the traditional quadrupole and the new linear ion trap scans (LIT) could be performed in a single LC run. In the past, a sample had to be run on two different instruments, namely, a triple quadrupole instrument (QqQ) and a 3D ion trap (3D IT) to obtain similar information. With the new QqQ(LIT) technology, collision-induced dissociation (CID) occur in a quadrupole collision cell, q2, and fragment ions are trapped and analyzed in Q3 operated in LIT mode. In this work, high-sensitivity product ion spectra of buspirone were obtained from the one-stage 'Enhanced Product Ion' scan (EPI) with rich product ions and no low mass cut-off. Furthermore, detailed fragmentation pathways were elucidated by further dissociation of each of the fragment ions in the EPI spectrum using MS(3) mode in the same run. The MS(3) scan was performed by incorporating CID in q2, and trapping, cooling, isolation, and resonance-excitation in Q3 when operating in LIT mode. This approach allowed unambiguous assignment of all fragment ions quickly with fewer experiments and easier interpretation than the previous approach. The overall sensitivity for obtaining complete fragment ion data was significantly improved for QqQ(LIT) as compared with that of QqQ and 3D IT mass spectrometers. This is beneficial for structure determination of unknown trace components. The method allowed structure determination of metabolites of buspirone in rat microsomes at 1 microM concentration, which was a 10-fold lower concentration than was needed for QqQ or 3D IT instruments. The QqQ(LIT) instrument provided a simple, rapid, sensitive and powerful approach for structure elucidation of trace components.


Assuntos
Buspirona/química , Buspirona/metabolismo , Animais , Buspirona/análogos & derivados , Buspirona/análise , Espectrometria de Massas/métodos , Estrutura Molecular , Ratos
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