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1.
PLoS One ; 8(10): e77828, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24204988

RESUMO

BACKGROUND: Oxaliplatin is an anticancer drug used for the treatment of advanced colorectal cancer, but it can also cause painful peripheral neuropathies. The pathophysiology of these neuropathies has not been yet fully elucidated, but may involve spinal N-methyl-D-aspartate (NMDA) receptors, particularly the NR2B subunit. As polyamines are positive modulators of NMDA-NR2B receptors and mainly originate from dietary intake, the modulation of polyamines intake could represent an interesting way to prevent/modulate neuropathic pain symptoms by opposing glutamate neurotransmission. METHODS: The effect of a polyamine deficient diet was investigated in an animal model of oxaliplatin-induced acute pain hypersensitivity using behavioral tests (mechanical and cold hypersensitivity). The involvement of spinal glutamate neurotransmission was monitored by using a proton nuclear magnetic resonance spectroscopy based metabolomic approach and by assessing the expression and phosphorylation of the NR2B subunit of the NMDA receptor. RESULTS: A 7-day polyamine deficient diet totally prevented oxaliplatin-induced acute cold hypersensitivity and mechanical allodynia. Oxaliplatin-induced pain hypersensitivity was not associated with an increase in NR2B subunit expression or phosphorylation, but with an increase of glutamate level in the spinal dorsal horn which was completely prevented by a polyamine deficient diet. As a validation that the oxaliplatin-induced hypersensitivity could be due to an increased activity of the spinal glutamate system, an intrathecal administration of the specific NR2B antagonist, ifenprodil, totally reversed oxaliplatin-induced mechanical and cold hypersensitivity. CONCLUSION: A polyamine deficient diet could represent a promising and valuable nutritional therapy to prevent oxaliplatin-induced acute pain hypersensitivity.


Assuntos
Comportamento Animal/efeitos dos fármacos , Dieta , Hiperalgesia/prevenção & controle , Neuralgia/prevenção & controle , Compostos Organoplatínicos/toxicidade , Poliaminas/metabolismo , Doença Aguda , Animais , Antineoplásicos/toxicidade , Temperatura Baixa , Ácido Glutâmico/metabolismo , Hiperalgesia/induzido quimicamente , Immunoblotting , Espectroscopia de Ressonância Magnética , Masculino , Metabolômica , Neuralgia/induzido quimicamente , Neuralgia/metabolismo , Oxaliplatina , Fosforilação , Piperidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Medula Espinal/patologia , Vasodilatadores/farmacologia
2.
Biomed Pharmacother ; 64(5): 363-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20106631

RESUMO

BACKGROUND: Reducing polyamine uptake by selecting low polyamine-containing foodstuffs and reducing bacterial gut production can improve performance status and pain control in hormone refractory prostate cancer (HRPC) patients. Long term PRD observance and tolerance were assessed. Cancer specific survival was studied in function of PRD and time of PRD initiation. METHODS: Twenty-six volunteers, age: 68+/-10 years with metastatic HRPC accepted a polyamine reduced diet and partial gut decontamination with oral neomycin or nifuroxazide (750 mg daily, one week out of two). Time from HRPC to PRD initiation was 10+/-8 months. WHO performance status, EORTC pain scale, body weight, blood counts and serum proteins were regularly assessed. Sixteen other HRPC patients eating a normal diet served as "controls". RESULTS: Mean diet observance is 25+/-24 months. Tolerance is good. WHO performance status and EORTC pain scales were significantly improved respectively at 3 months (0.5+/-0.7 vs 0.7+/-0.9: p=0.03) and 6 months (0.5+/-0.8 vs 1+/-1.3, p=0.02) compared to initial values. Median cancer specific survival times after HRPC and PRD initiation are respectively 36 and 21 months. Eleven PRD patients started the diet before a 9 months cut-off period (after HRPC) and 15 patients after. Median cancer specific survival times for these two groups of patients are respectively 44 and 34 months, p=0.014. Median cancer specific survival times (after HRPC) for PRD patients compared to controls are 36 vs 17 months (p=0.004). CONCLUSIONS: Polyamine-reduced diet is well observed and tolerated. It seems to improve and/or maintain quality of life for HRPC patients. Early PRD initiation in HRPC is promising and may impact favorably cancer specific survival. These results open a rationale for PRD in HRPC management and warrant further investigation.


Assuntos
Poliaminas/administração & dosagem , Neoplasias da Próstata/dietoterapia , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Anti-Infecciosos/uso terapêutico , Descontaminação/métodos , Trato Gastrointestinal/microbiologia , Humanos , Hidroxibenzoatos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Neomicina/uso terapêutico , Nitrofuranos/uso terapêutico , Dor/dietoterapia , Dor/etiologia , Medição da Dor , Estudos Prospectivos , Neoplasias da Próstata/patologia , Sobrevida , Fatores de Tempo , Resultado do Tratamento
3.
Behav Brain Res ; 190(1): 119-23, 2008 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-18378328

RESUMO

The present study aimed to examine the effects of an acute administration of the mu-opioid receptor fentanyl on affect as assessed by place-conditioning procedure in rats. We determined the affective properties of fentanyl not only immediately following its administration, but also 24h later. Experiments were performed using the dose of fentanyl (240 gamma/kg; four injections of 60 gamma/(ml kg) every 15 min, subcutaneously) for which secondary hyperalgesia has been previously described. Our results show that the acute administration of fentanyl display biphasic affective properties, with early rewarding and 24-h delayed aversive components. The 24-h delayed aversive effects of fentanyl were not observed in animals submitted to a polyamine-deficient diet, suggesting an NMDA-dependent mechanism.


Assuntos
Aminas/metabolismo , Analgésicos Opioides/administração & dosagem , Condicionamento Operante/efeitos dos fármacos , Deficiências Nutricionais/prevenção & controle , Fentanila/administração & dosagem , Animais , Comportamento Animal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Esquema de Medicação , Masculino , Ratos , Ratos Long-Evans , Recompensa , Comportamento Espacial/efeitos dos fármacos , Fatores de Tempo
4.
Pain ; 137(1): 125-137, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17900809

RESUMO

There is a compelling body of evidence that N-methyl-d-aspartate receptors (NMDA-R) play a critical role in the development and maintenance of pain hypersensitivity. However, long-term treatments with NMDA-R antagonists are limited by unacceptable side effects. Since polyamines modulate the functioning of NMDA-R and mainly originate from normal dietary intake and bacterial metabolism in the gut, we developed a nutritional therapy based on dietary polyamine deficiency. Here, we reported that a polyamine deficient diet (PD diet) for 7 days prevented the enhancement of tyrosine phosphorylation of the spinal NR2B subunit-containing NMDA-R associated with inflammation in rats. Based on these data, we studied the ability of PD diet to prevent long-lasting pain hypersensitivity associated with tissue injury on one hind paw by evaluating long-lasting changes in both mechanical nociceptive threshold and weight bearing. A PD diet strongly reduced long-lasting hyperalgesia induced by inflammation or incision, especially in fentanyl-treated rats. Moreover a PD diet also prevented the exaggerated hyperalgesia induced by a second inflammation performed 7 days after the first one. A PD diet also opposed paradoxical hyperalgesia induced by non-nociceptive environmental stress in rats with pain and opioid experiences. A PD diet reversed pain hypersensitivity associated with monoarthritis or neuropathy and restored the analgesic effect of morphine. Since PD diet was devoid of any noticeable side effects, this nutritional therapy could be part of an effective and safe strategy for pre-emptive analgesia and for reducing the transition from acute to chronic pain and its outcomes in various pain syndromes.


Assuntos
Dietoterapia/métodos , Hiperalgesia/dietoterapia , Poliaminas/administração & dosagem , Animais , Hiperalgesia/metabolismo , Masculino , Medição da Dor/métodos , Putrescina/administração & dosagem , Ratos , Ratos Sprague-Dawley
5.
Cancer Lett ; 251(2): 317-22, 2007 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-17207571

RESUMO

1-O-alkylglycerols (alkyl-Gro) are natural etherlipids with multiple biological activities. We previously demonstrated that alkyl-Gro reduce endothelial permeability. Here we showed that alkyl-Gro reduced the basic Fibroblast Growth Factor (bFGF)-stimulated endothelial cell proliferation in a concentration-dependent manner. The effects of 0.5 and 5 ng/ml bFGF on growth were completely suppressed after 72 h-treatment by 50 microM alkyl-Gro. Since bFGF greatly increased (+56%+/-15) the production of 1-O-alkyl-2-acyl-sn-glycerophosphate in alkyl-Gro-treated endothelial cells, our data suggest that the observed effects of alkyl-Gro could be mediated through PLD activation. Inhibition of bFGF-stimulated endothelial proliferation could support anti-angiogenic activity of alkyl-Gro.


Assuntos
Células Endoteliais/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Glicerol/análogos & derivados , Éteres de Glicerila/farmacologia , Inibidores da Angiogênese , Animais , Bovinos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Endotélio Vascular , Glicerol/farmacologia , Células Tumorais Cultivadas
6.
Anesth Analg ; 102(6): 1781-8, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16717326

RESUMO

Polyamines are thought to be involved in the regulation of numerous metabolic and electrophysiological processes in the nervous system. In this study we evaluated the effect of a synthetic polyamine-deficient diet on pain in a carrageenan (Car)-induced inflammatory rat model. Inflammation was induced with a unilateral subcutaneous injection of Car in a plantar hindpaw in rats fed without (control group) or with (deficiency group) a polyamine-deficient diet. Ipsilateral and contralateral hyperalgesia was evaluated using the Randall-Sellito pressure test. Heart rate changes were also recorded under general anesthesia. Then, the effects of a bupivacaine sciatic nerve block and subcutaneous injection of naloxone or ketamine were evaluated for Car-induced hyperalgesia. Data were analyzed using analysis of variance followed by unpaired Student's t-test (significance P < 0.05). Before Car injection, no significant difference was observed in response to mechanical stimuli between the control and the deficiency groups (n = 114 in pooled data). Car injection induced significant ipsilateral and contralateral hyperalgesia in the control groups, whereas a significant analgesic effect appeared in the deficient groups on both the ipsilateral and contralateral hindpaws. This analgesic effect was confirmed by the electrocardiogram recording that showed a significant increase in heart rate in the control group after Car injection compared with the deficiency group that showed a decrease in heart rate under general anesthesia. Bupivacaine sciatic nerve block had no significant effect on hypoalgesia phenomena induced by polyamine deficiency. Naloxone administration had no effect in the control group but reversed the analgesic effect in the deficiency group. Ketamine administration induced a significant analgesic effect in the control group and partly reversed the analgesic effect in the deficiency group. In conclusion, a synthetic polyamine-deficient diet had a significant general analgesic effect on Car-induced mechanical hyperalgesia. The mechanism of analgesic action remains to be elucidated.


Assuntos
Analgesia , Dieta , Hiperalgesia/dietoterapia , Poliaminas/administração & dosagem , Analgésicos/farmacologia , Animais , Carragenina , Membro Posterior , Hiperalgesia/induzido quimicamente , Hiperalgesia/fisiopatologia , Hiperalgesia/terapia , Inflamação/induzido quimicamente , Ketamina/farmacologia , Masculino , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Bloqueio Nervoso , Limiar da Dor , Ratos , Ratos Sprague-Dawley , Nervo Isquiático
7.
J Med Chem ; 48(22): 7024-39, 2005 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-16250662

RESUMO

The human selenoprotein thioredoxin reductase is involved in antioxidant defense and DNA synthesis. As increased thioredoxin reductase levels are associated with drug sensitivity to cisplatin and drug resistance in tumor cells, this enzyme represents a promising target for the development of cytostatic agents. To optimize the potential of the widely used cisplatin to inhibit the human thioredoxin reductase and therefore to overcome cisplatin resistance, we developed and synthesized four cis-diamminedichloroplatinum complexes of the lead 5-nitro-2-furancarbohydrazide 8 selected from high-throughput screening. Detailed kinetics revealed that the isolated fragments, 5-nitro-2-furancarbohydrazide and cisplatin itself, bind with micromolar affinities at two different subsites of the human enzyme. By tethering both fragments four nitrofuran-based cis-diamminedichloroplatinum complexes 13a-c and 20 were synthesized and identified as bi-ligand irreversible inhibitors of the human enzyme with nanomolar affinities. Studies with mutant enzymes clearly demonstrate the penultimate selenocysteine residue as the prime target of the synthesized cis-diamminedichloroplatinum complexes.


Assuntos
Antineoplásicos/síntese química , Furanos/síntese química , Hidrazinas/síntese química , Compostos Organoplatínicos/síntese química , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Drosophila melanogaster , Ensaios de Seleção de Medicamentos Antitumorais , Furanos/química , Furanos/farmacologia , Humanos , Hidrazinas/química , Hidrazinas/farmacologia , Cinética , Camundongos , Nitrorredutases/química , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacologia , Relação Estrutura-Atividade , Tiorredoxina Dissulfeto Redutase/química , Fatores de Tempo
8.
Pediatr Dev Pathol ; 8(4): 463-73, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16211458

RESUMO

Improvements in the diagnosis of congenital malformations explain the increasing early termination of pregnancies. Before 13 weeks of gestation, an accurate in vivo anatomic diagnosis cannot currently be made in all fetuses with current imaging instrumentation. Anatomopathologic examinations remain the gold standard to make accurate diagnoses, although they reach limits between 9 and 13 weeks of gestation. We present the first results of a methodology that can be applied routinely, using standard histologic section, thus enabling the reconstruction, visual estimate, and quantitative analysis of 13-week human embryonic cardiac structures. The cardiac blocks were fixed, embedded in paraffin, and entirely sliced by a microtome. One of 10 slices was topographically colored and digitized on an optical microscope. Cardiac volume was recovered by semiautomatic realignment of the sections. Another semiautomatic procedure allowed extracting and labeling of cardiac structures from the volume. Structures were studied with display tools, which disclosed the internal and external cardiac components and enabled determination of size, thickness, and precise positioning of ventricles, atria, and large vessels. This pilot study confirmed that a new 3-dimensional reconstruction and visualization method enables accurate diagnoses, including in embryos younger than 13 weeks. Its implementation at earlier stages of embryogenesis will provide a clearer view of cardiac development.


Assuntos
Cardiopatias Congênitas/diagnóstico , Coração/embriologia , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Organogênese/fisiologia , Primeiro Trimestre da Gravidez , Adulto , Feminino , Cardiopatias Congênitas/embriologia , Humanos , Projetos Piloto , Gravidez
10.
Redox Rep ; 10(1): 9-18, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15829106

RESUMO

Structural analogues of natural polyamines, which contain a -Si(CH3)2 group in the central carbon chain, have previously been found to be cytotoxic to various tumor cell lines in vitro and to inhibit tumor cell growth in experimentally grafted animals. In the present study, the antioxidative properties of dimethylsilane polyamine analogues were analyzed in comparison with the natural polyamines. Reactivities of these various polyamines against superoxide anions (generated from the hypoxanthine/xanthine oxidase reaction) and peroxyl radicals (produced from the thermal decomposition of water-soluble 2,2'-azo-bis-[2-amidinopropane] hydrochloride) were investigated. The dimethysilane analogues, and more particularly the hexamine derivative, exhibited the highest scavenging efficiency towards these two reactive oxygen species (ROS). Furthermore, analysis of their ability to prevent hydroxyl radical formation and to trap this ROS showed that the efficiency of the hexamine as a metal chelator and hydroxyl radical scavenger is similar to that of spermine. The higher antioxidant efficiency of the dimethylsilane polyamine analogues with respect to spermidine, together with their ability to displace this polyamine, essential for the promotion of cell growth, from its cellular anionic binding sites that are particularly prone to oxidation, could be biologically relevant and contribute to their in vivo cytotoxic effect and anti-tumor activity. Further experiments will be necessary to demonstrate clearly the relationship between their antioxidant properties and their antiproliferative effects.


Assuntos
Eritrócitos/metabolismo , Poliaminas/farmacologia , Silanos/farmacologia , Antioxidantes/metabolismo , Eritrócitos/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Humanos , Radical Hidroxila/antagonistas & inibidores , Metenamina/farmacologia , Valores de Referência , Espermidina/farmacologia , Espermina/farmacologia , Relação Estrutura-Atividade
11.
Hum Pathol ; 35(10): 1279-84, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15492997

RESUMO

Renal cell carcinoma (RCC) is known to display a wide variation in biological behavior and clinical outcome. Although usual bioclinical prognostic parameters (eg, nuclear grade, tumor stage) are to a certain extent useful in predicting the outcome of RCC after radical nephrectomy, they now appear to be insufficient. The polyamines (spermidine, spermine, and putrescine) are ubiquitous polycations that are essential for cell proliferation. To support their excessive proliferation, cancer cells have high rates of polyamine metabolism. Indeed, malignant cells typically have higher polyamine levels than their normal counterparts. Before this report, antipolyamine antibodies that are potentially valuable tools for the in situ observation of polyamines had not been exploited in clinical conditions. In the present study, tumor tissues obtained from radical nephrectomy performed for RCC (n = 73) were immunostained with the anti-spermine monoclonal antibody Spm8-2, and the immunoreactivity was evaluated as a prognostic tool. RCC cells displayed various reactivity to the antibody Spm8-2 that translated into a heterogeneous cytoplasmic staining. The prognostic value of the labeling index (LI) on clinical outcome was correlated with the usual clinicopathologic parameters, and the cell proliferation rate was evaluated using Ki-67 labeling. Multiple correspondence analysis and ascending hierarchical classification were performed to determine significant prognostic factors. Univariate statistical survival analysis demonstrated that tumor size (P < .001), nuclear grade (P < .01), necrosis (P < .007), tumor stage (P < .004), metastasis (P < .001), Ki-67 LI (P < .0003), and Spm8-2 immunoreactivity (P < .0001) were predictors of tumor-related death. A positive correlation was found between Ki-67 LI and Spm8-2 immunoreactivity (r' = .53). Multivariate analysis revealed that only Ki-67 LI and Spm8-2 immunoreactivity were significant independent factors in patients with metastases (P < .04 and <.001, respectively) and in patients without metastases (P < .006 and <.001, respectively). Moreover, 100% of the patients with Spm8-2 immunoreactivity <10% were alive at the end of the follow-up. In terms of predictive values, Spm8-2 immunoreactivity had the highest predictive values (sensitivity, 89; specificity, 75; risk ratio, 11) of all clinicopathologic parameters. This study demonstrates that the anti-spermine monoclonal antibody Spm8-2 may be used at the time of radical nephrectomy as a reliable prognostic marker for defining RCC patients at high risk for progression.


Assuntos
Carcinoma de Células Renais/diagnóstico , Imuno-Histoquímica/métodos , Neoplasias Renais/diagnóstico , Espermina/análise , Adulto , Idoso , Anticorpos Monoclonais , Biomarcadores Tumorais , Progressão da Doença , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Renais/metabolismo , Masculino , Pessoa de Meia-Idade , Nefrectomia , Prognóstico , Fatores de Risco , Análise de Sobrevida
12.
Nutr Cancer ; 48(1): 64-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15203379

RESUMO

Alkylglycerols are natural etherlipids abundant in shark liver oil (SLO) in a diacylated form. SLO is known to have antitumor properties and was recently described as an inhibitor of tumor neovascularization. However, most studies did not discriminate between the respective activities of alkylglycerols and of fatty acids, which both have potent biological properties. In this work, a mouse model was used to investigate the antitumor effects of SLO and of alkylglycerols purified from the same source, both administered orally. We demonstrated that either pure alkylglycerols or SLO reduced the tumor growth in a similar manner, suggesting that alkylglycerols were involved in this effect. In alkylglycerol-treated mice, metastasis dissemination was reduced by 64 +/- 8%, whereas SLO effect was 30 +/- 9% below control. Purified alkylglycerols also decreased significantly plasmalogen content in tumors, whereas SLO had no such effect. Finally, we demonstrated that a 5-day treatment with alkylglycerols curtailed the presence in tumors of von Willebrand factor, a marker of endothelial cells. This result suggested an anti-angiogenic effect of alkylglycerols. In summary, alkylglycerols were shown to decrease the growth, vascularization, and dissemination of Lewis lung carcinoma tumors in mice. These findings suggest that the antitumor activity of SLO is likely mediated by the presence of alkylglycerols.


Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Óleos de Peixe/química , Glicerol/farmacologia , Metástase Neoplásica/prevenção & controle , Animais , Carcinoma Pulmonar de Lewis/irrigação sanguínea , Carcinoma Pulmonar de Lewis/patologia , Divisão Celular/efeitos dos fármacos , Feminino , Óleos de Peixe/farmacologia , Glicerol/química , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Patológica/prevenção & controle , Tubarões , Células Tumorais Cultivadas , Fator de von Willebrand
13.
Biochem Pharmacol ; 67(9): 1629-37, 2004 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-15081862

RESUMO

Polyamines are ubiquitous molecules, which, like iron, are essential for cell growth. All eukaryotic cells are equipped with a specific polyamine transport system (PTS). Polyamines have primary and secondary amino groups which chelate bivalent metal cations such as Fe and Cu. In the present study, we investigated the potential contribution of naturally occurring polyamines and their active transport system to iron uptake. In presence of subtoxic Fe(III) (10microM), treatment of CHO cells with spermine, and to a lesser extent with spermidine (10-100microM), resulted in a marked cytotoxic effect. This cytotoxicity was prevented by the addition of an iron-chelator, deferioxamine, and was not observed in CHO-MG cells, a mutant cell line devoid of polyamine transport activity. Experiments using 14C-polyamines and 55Fe(III) revealed that these toxic effects were related to polyamine-modulation of iron uptake, and were dependent on the presence of the active PTS. These results demonstrated active uptake of polyamine-iron complexes via the PTS. The number of amino groups affected the efficacy of the studied natural polyamines to transport iron via the PTS. Spermine, a tetramine, was more efficient than the triamine spermidine. Co-transport of iron by the diamine putrescine was not observed. These results demonstrate that the cell polyamine transport system is a potential cell entry pathway for iron. The studied polyamines, spermine and spermidine, may be components of the pool of transferrin-independent iron-chelating vectors, which have recently attracted the attention of many investigators.


Assuntos
Ferro/metabolismo , Poliaminas/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Células CHO , Membrana Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Compostos Férricos/farmacologia , Poliaminas/metabolismo , Espermina/farmacologia
14.
Anal Biochem ; 318(2): 212-20, 2003 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-12814624

RESUMO

Determination of polyamine pools is still a step impossible to circumvent in studies aimed at determining the pathophysiological role of natural polyamines. In addition, polyamine measurement in biological fluids and tissues may have clinical relevance, especially in cancer patients. Among the wide panel of analytical methods developed for the quantification of polyamines, high-performance liquid chromatographic (HPLC) separation of polyamines after derivatization with dansyl chloride remains the most commonly used method. In this work, we show that atmospheric pressure chemical ionization-mass spectrometry (MS) can be used to detect and quantify biologically relevant polyamines after dansylation, without chromatographic separation. Positive-ion mass spectra for each dansylated polyamine were generated after optimization by flow injection analysis (FIA). FIA coupled with MS detection by selected ion monitoring greatly increased the sensitivity of the polyamine detection. The method is linear over a wide range of polyamine concentrations and allows detection of quantities as low as 5 fmol. The FIA/MS method is about 50-fold more sensitive than the conventional HPLC/fluorimetry procedure. A good correlation (r>0.98) between these two methods was observed. The FIA/MS method notably reduces the time of analysis per sample to 1.5 min and turns out to be rapid, efficient, cost saving, reproducible, and sufficiently simple to allow its routine application.


Assuntos
Compostos de Dansil/análise , Espectrometria de Massas/métodos , Poliaminas/análise , Poliaminas/química , Animais , Pressão Atmosférica , Células CHO , Cricetinae , Compostos de Dansil/química , Humanos , Poliaminas/sangue , Poliaminas/líquido cefalorraquidiano , Padrões de Referência , Reprodutibilidade dos Testes
16.
J Pharmacol Toxicol Methods ; 47(1): 33-43, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12387937

RESUMO

INTRODUCTION: Reactive oxygen species (ROS) contribute to the development of pathophysiological processes, hence the increasing interest in modulating the antioxidant status of patient by nutritional or pharmacological intervention. Antioxidants act by preventing the formation of ROS (inhibitory effect) and/or by trapping these species (scavenger effect). We have developed a simple, sensitive, and reliable test to measure the total antioxidative efficiency of plasma or other biological fluids using microliter samples. METHODS: Autoxidation of homovanillic acid (HVA) gives rise to fluorescent dimers. Antioxidants contained in the plasma (or free aqueous solutions) scavenge the ROS involved in this process and transiently stop the linear increase in fluorescence intensity during a time (delay) proportional to the total concentration of antioxidants and their scavenging efficiency. In addition to this scavenging effect, the kinetics of HVA autoxidation, restarting after the delay, reflects the ability of the plasma antioxidants to inhibit the ROS-triggered autoxidation. RESULTS: The rate of the HVA autoxidation depended on the temperature, the protonation of the phenolic group, and on the presence of peroxide, peroxyl radicals, and peroxidase as well as metal ions. This Fenton-like reaction was transiently stopped by various ROS scavengers including quercetin, ascorbic acid, and thiol derivatives (glutathione and N-acetylcystein) while metal chelating agents such as desferrioxamine, ethylene diamine tetracetic acid (EDTA), and polyamine only reduced its rate. DISCUSSION: The main advantages of this new assay are its versatility to investigate in a single run both the scavenging and inhibitory components of the antioxidant capacity, and its relevance to the reactive hydroxyl radical. As shown in this study, the increase in the antioxidant capacity of human plasma during pharmacological supplementation with antioxidant illustrates one of the various fields of application of this assay.


Assuntos
Antioxidantes/metabolismo , Bioensaio , Ácido Homovanílico/sangue , Animais , Antioxidantes/análise , Quelantes/farmacologia , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Sequestradores de Radicais Livres/análise , Sequestradores de Radicais Livres/metabolismo , Masculino , Espectrometria de Massas , Oxirredução , Ratos , Ratos Endogâmicos , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Anesth Analg ; 95(4): 992-6, table of contents, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12351282

RESUMO

We studied the inhibition of peroxidation by local anesthetics in an inflammatory animal model. Inflammatory lipid peroxidation was assessed by the thiobarbituric assay in plasma from rats injected or not injected with carrageenan (Carra) and killed 1, 2, 4, 6, 12, and 24 h thereafter. Thiobarbituric acid reactive substances (TBARS) values in inflammatory animals were maximal 6 h after Carra administration. This result, in accordance with the evolution of paw edema width during time, supports that TBARS reflect the intensity of inflammation. Local anesthetics (bupivacaine, lidocaine, ropivacaine, or bupivacaine-loaded microspheres) or amitriptyline were injected in clinically relevant concentrations as a sciatic nerve block or intraperitoneally in inflamed animals. Ropivacaine did not exhibit any protective effect on Carra-induced lipid peroxidation in rats. With all the other drugs administered as a sciatic nerve block, the maximal TBARS increase was not observed at 6 h. Our conclusion is that bupivacaine (plain or encapsulated), lidocaine, and amitriptyline in clinically relevant concentrations administered via the sciatic nerve showed antioxidant properties toward lipid peroxidation induced by Carra inflammation. Intraperitoneal injection of those drugs gave the same effect as nerve block; this result suggests that their mechanism of action is not strictly limited to the nerve. IMPLICATIONS. We investigated the antioxidant effects of local anesthetics and amitriptyline in an inflammatory rat model. Amitriptyline exhibits antioxidant properties per se, whereas lidocaine and bupivacaine (plain or encapsulated) seem to inhibit the peroxidation process. This may have future application in limiting toxic oxygen metabolite production during the inflammatory process.


Assuntos
Amitriptilina/farmacologia , Anestésicos Locais/farmacologia , Antidepressivos Tricíclicos/farmacologia , Inflamação/tratamento farmacológico , Peroxidação de Lipídeos/efeitos dos fármacos , Amidas/farmacologia , Animais , Bupivacaína/farmacologia , Bupivacaína/uso terapêutico , Carragenina , Inflamação/induzido quimicamente , Inflamação/patologia , Lidocaína/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Ropivacaina , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
18.
Can J Anaesth ; 49(7): 690-3, 2002.
Artigo em Inglês, Francês | MEDLINE | ID: mdl-12193487

RESUMO

PURPOSE: The aim of this study was to evaluate the effect of different durations of local anesthetic neural blockade on hyperalgesia after carrageenan infiltration in a rat model. METHODS: Inflammation was obtained by injection of carrageenan in the righ hind paw. Hyperalgesia was determined by measuring the threshold of response to increasing mechanical stimuli on the contralateral and on the ipsilateral paw. The development of edema was measured. After identification of the sciatic nerve by nerve stimulation, blockade was performed either one hour before or after carrageenan infiltration. Animals were randomly assigned into three groups: without sciatic nerve block (control group; n = 20), block with bupivacaine (B) and block with bupivacaine-loaded microspheres (B-Ms) injection before or after carrageenan infiltration (n = 10 for each group). RESULTS: Carrageenan infiltration in the control group induced a severe ipsilateral and contralateral hyperalgesia. After blockade with B (duration = 2 +/- 0.5 hr) hyperalgesia was present and delayed only by the duration of the local anesthetic effect. A longer duration of block achieved with B-Ms (duration greater than five hours), was associated with the absence of development of both ipsilateral and contralateral hyperalgesia. No preemptive effect was recorded. CONCLUSION: B-Ms as a drug delivery system prolongs the duration of neural blockade and avoids hyperalgesia phenomena in this rat model of inflammation.


Assuntos
Anestésicos Locais/administração & dosagem , Bupivacaína/administração & dosagem , Hiperalgesia/prevenção & controle , Bloqueio Nervoso , Nervo Isquiático , Animais , Masculino , Microesferas , Modelos Animais , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
19.
Int J Oncol ; 21(3): 569-76, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12168101

RESUMO

Polyamines are essential for rapidly dividing cells such as enterocytes and tumour cells. In both cells, polyamine pools are maintained by biosynthetic pathways along with active uptake systems. Because of their strategic position, enterocytes play an important role in the trafficking of luminal polyamines. The aim of this study was to determine whether the high polyamine demanding MAT-LyLu prostatic tumour alter the absorption and metabolism of putrescine in the small intestine tissue of rats. In vivo, after intragastric intubation of [14C]-putrescine, both the uptake of putrescine and its metabolic conversion into non-polyamine metabolites were enhanced in the small intestine of tumour-bearing rats. The presence of the tumour also altered the biodistribution of the radioactivity with a striking increased level of radioactivity in the plasma, which was probably the consequence of a higher net flux of putrescine from the lumen to the blood. Ex vivo studies using everted small intestine segments supported this hypothesis. The stimulation of putrescine uptake and metabolism in enterocytes of tumour-bearing animals may be an adaptation to compensate for the energy deficit caused by the competition with the tumour for nutrients and worsened by the tumour-associated cachexy.


Assuntos
Intestino Delgado/metabolismo , Neoplasias da Próstata/metabolismo , Putrescina/farmacocinética , Amina Oxidase (contendo Cobre)/metabolismo , Animais , Radioisótopos de Carbono , Enterócitos/enzimologia , Enterócitos/metabolismo , Absorção Intestinal/fisiologia , Jejuno/enzimologia , Jejuno/metabolismo , Masculino , Ratos , Distribuição Tecidual , Células Tumorais Cultivadas
20.
Bioorg Med Chem ; 10(9): 2863-71, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12110306

RESUMO

Polyamine vectors are attractive for tumor targeting. We envisaged (Z)-1,4-diamino-2-butene (Z-DAB), an unsaturated analogue of putrescine as vector of (10)B, (18)F and (131)I for boron neutron capture therapy (BNCT), and tumor imaging by positron emission tomography or scintigraphy respectively. In the present work, the synthesis and characterization of new derivatives of Z-DAB were reported. Z-DAB was actively transported in cells via the polyamine transport system and converted into the spermidine analogue.(E)-2-iodo-1,4-diamino-2-butene (E-I-DAB) was not taken up by the polyamine transport system and may not be suitable for tumor imaging. In contrast, (Z)-2-[4-(5,5-dimethyl-dioxaborinan-2-yl)phenyl]methyl-1,4-diamino-2-butene (Z-4-Bbz-DAB) was a substrate of the transport system and allowed significant boron accumulation in 3LL cells. Its potential in BNCT will be evaluated.


Assuntos
Putrescina/análogos & derivados , Putrescina/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Animais , Transporte Biológico , Boro/uso terapêutico , Células CHO , Divisão Celular/efeitos dos fármacos , Cricetinae , Relação Dose-Resposta a Droga , Radioisótopos de Flúor/uso terapêutico , Halogênios/uso terapêutico , Humanos , Radioisótopos do Iodo/uso terapêutico , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Poliaminas/metabolismo , Putrescina/uso terapêutico , Radioisótopos/uso terapêutico , Cintilografia , Compostos Radiofarmacêuticos/uso terapêutico , Células Tumorais Cultivadas
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