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1.
Drug Metab Rev ; 46(2): 224-31, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24378227

RESUMO

The purpose of the current studies was to determine if systemic exposure of various metallic nanoparticles differing in size and composition [silver (Ag-NPs, 25, 40 and 80 nm), copper-oxide (Cu-NPs, 40 and 60 nm) or gold (Au-NPs, 3 and 5 nm)] can induce the release of pro-inflammatory mediators that influence the restrictive nature of the blood-brain barrier (BBB) in vitro. Confluent porcine brain microvessel endothelial cells (pBMECs) (8-12 days) were treated with various metallic nanoparticles (15 µg/ml). Extracellular concentrations of pro-inflammatory mediators (IL-1ß, TNFα and PGE2) were evaluated using ELISA. pBMECs were cultured in standard 12-well Transwell® inserts, and permeability was evaluated by measuring the transport of fluorescein across the pBMEC monolayers. PGE2 release following Cu-NP exposure was significantly increased when compared to the control. Similar results were observed for Ag-NPs but not Au-NPs. The secretion of TNFα and IL-1ß was observed for both Cu-NPs and Ag-NPs but not in response to Au-NPs. The post-treatment time profiles of TNFα and IL-1ß revealed that the IL-1ß response was more persistent. The permeability ratios (exposure/control) were significantly greater following exposure to Cu-NPs or Ag-NPs, compared to Au-NPs. Together, these data suggest that the composition and size of NPs can cause significant pro-inflammatory response that can influence the integrity of the BBB.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Mediadores da Inflamação/imunologia , Nanopartículas Metálicas/toxicidade , Microvasos/efeitos dos fármacos , Animais , Barreira Hematoencefálica/citologia , Barreira Hematoencefálica/imunologia , Dinoprostona/imunologia , Dinoprostona/metabolismo , Células Endoteliais/imunologia , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Nanopartículas Metálicas/química , Microvasos/citologia , Microvasos/imunologia , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/imunologia , Tamanho da Partícula , Propriedades de Superfície , Suínos , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
2.
J Appl Toxicol ; 34(5): 480-8, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23696345

RESUMO

Ketamine, a dissociative anesthetic, is a noncompetitive antagonist of N-methyl-D-aspartate-type glutamate receptors. In rodents and non-human primates as well as in zebrafish embryos, ketamine has been shown to be neurotoxic. In cyclic female rats, ketamine has been shown to decrease serum estradiol-17ß (E2) levels. E2 plays critical roles in neurodevelopment and neuroprotection. Cytochrome p450 (CYP) aromatase catalyzes E2 synthesis from androgens. Although ketamine down-regulates a number of CYP enzymes in rodents, its effect on the CYP aromatase (CYP19) is not known. Zebrafish have been used as a model system for examining mechanisms underlying drug effects. Here, using wild-type (WT) zebrafish (Danio rerio) embryos, we demonstrate that ketamine significantly reduced E2 levels compared with the control. However, the testosterone level was elevated in ketamine-treated embryos. These results are concordant with data from mammalian studies. Ketamine also attenuated the expression of the ovary form of CYP aromatase (cyp19a1a) at the transcriptional level but not the brain form of aromatase, cyp19a1b. Exogenous E2 potently induced the expression of cyp19a1b and vtg 1, both validated biomarkers of estrogenicity and endocrine disruption, but not cyp19a1a expression. Attenuation of activated ERK/MAPK levels, reportedly responsible for reduced human cyp19 transcription, was also observed in ketamine-treated embryos. These results suggest that reduced E2 levels in ketamine-treated embryos may have resulted from the suppression of cyp19a1a transcription.


Assuntos
Aromatase/genética , Embrião não Mamífero/efeitos dos fármacos , Estradiol/análise , Expressão Gênica/efeitos dos fármacos , Ketamina/toxicidade , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/embriologia , Animais , Cromatografia Líquida de Alta Pressão , Embrião não Mamífero/enzimologia , Embrião não Mamífero/metabolismo , Peixe-Zebra/sangue , Peixe-Zebra/genética
3.
Neurotoxicol Teratol ; 39: 69-76, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23896048

RESUMO

Ketamine, a non-competitive antagonist of N-methyl-D-aspartate (NMDA) type glutamate receptors is commonly used as a pediatric anesthetic. Multiple studies have shown ketamine to be neurotoxic, particularly when administered during the brain growth spurt. Previously, we have shown that ketamine is detrimental to motor neuron development in the zebrafish embryos. Here, using both wild type (WT) and transgenic (hb9:GFP) zebrafish embryos, we demonstrate that ketamine is neurotoxic to both motor and sensory neurons. Drug absorption studies showed that in the WT embryos, ketamine accumulation was approximately 0.4% of the original dose added to the exposure medium. The transgenic embryos express green fluorescent protein (GFP) localized in the motor neurons making them ideal for evaluating motor neuron development and toxicities in vivo. The hb9:GFP zebrafish embryos (28 h post fertilization) treated with 2 mM ketamine for 20 h demonstrated significant reductions in spinal motor neuron numbers, while co-treatment with acetyl L-carnitine proved to be neuroprotective. In whole mount immunohistochemical studies using WT embryos, a similar effect was observed for the primary sensory neurons. In the ketamine-treated WT embryos, the number of primary sensory Rohon-Beard (RB) neurons was significantly reduced compared to that in controls. However, acetyl L-carnitine co-treatment prevented ketamine-induced adverse effects on the RB neurons. These results suggest that acetyl L-carnitine protects both motor and sensory neurons from ketamine-induced neurotoxicity.


Assuntos
Acetilcarnitina/farmacologia , Ketamina/antagonistas & inibidores , Ketamina/toxicidade , Neurônios Motores/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Células Receptoras Sensoriais/efeitos dos fármacos , Peixe-Zebra/embriologia , Acetilcarnitina/farmacocinética , Anestésicos Dissociativos/antagonistas & inibidores , Anestésicos Dissociativos/toxicidade , Animais , Animais Geneticamente Modificados , Relação Dose-Resposta a Droga , Embrião não Mamífero , Neurogênese/efeitos dos fármacos , Fármacos Neuroprotetores/farmacocinética
4.
Neurosci Lett ; 515(2): 107-10, 2012 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-22414866

RESUMO

The neurotoxins methamphetamine (METH) and MPTP are well-known for their effects on the nigrostriatal dopaminergic system and use in modeling neurodegenerative disorders such as Parkinson's disease. It is not well-known though, how METH or MPTP affects the visual system and specifically the retinal dopaminergic system. This study was designed to examine acute effects of multiple doses of METH and MPTP on the retinal dopaminergic system. Mice were exposed to either low- (LD) 10 mg/kg total dose or high-dose (HD) 30 mg/kg total dose, of METH or MPTP and the retinal catecholaminergic system was analyzed by HPLC. METH produced no significant changes in dopamine (DA), its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) or DA usage in the retina. LD-MPTP produced no change in DA level, but significantly decreased DOPAC and HVA. LD-MPTP also significantly decreased DA usage as measured by the DOPAC/DA and HVA/DA ratios. HD-MPTP significantly decreased DA, DOPAC and HVA, but did not affect DA usage. Taken together these results suggest that inhibition of the DA metabolizing enzymes monoamine oxidase A (MAO) or catechol-O-methyl transferase (COMT) may take place at lower doses of MPTP treatment; conversely, higher doses of MPTP may cause decreases in DA, DOPAC and HVA through another mechanism.


Assuntos
1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Dopaminérgicos/farmacologia , Dopamina/metabolismo , Neurotoxinas/farmacologia , Retina/efeitos dos fármacos , Animais , Catecol O-Metiltransferase/metabolismo , Ácido Homovanílico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Retina/metabolismo
5.
Nanomedicine (Lond) ; 7(6): 835-46, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22339089

RESUMO

AIM: The purpose of the current study was to determine whether copper nanoparticles (Cu-NPs) can induce the release of proinflammatory mediators that influence the restrictive characteristics of the blood-brain barrier. MATERIAL & METHODS: Confluent rat brain microvessel endothelial cells (rBMECs) were treated with well-characterized Cu-NPs (40 or 60 nm). Cytotoxicity of the Cu-NPs was evaluated by cell proliferation assay (1.5-50 µg/ml). The extracellular concentrations of proinflammatory mediators (IL-1ß, IL-2, TNF-α and prostaglandin E(2)) were evaluated by ELISA. RESULTS: The exposure of Cu-NPs at low concentrations increases cellular proliferation of rBMECs, by contrast, high concentrations induce toxicity. Prostaglandin E(2) release was significantly increased (threefold; 8 h) for Cu-NPs (40 and 60 nm). The extracellular levels of both TNF-α and IL-1ß were significantly elevated following exposure to Cu-NPs. The P-apparent ratio, as an indicator of increased permeability of rBMEC was approximately twofold for Cu-NPs (40 and 60 nm). CONCLUSION: These data suggest that Cu-NPs can induce rBMEC, proliferation at low concentrations and/or induce blood-brain barrier toxicity and potential neurotoxicity at high concentrations.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/imunologia , Cobre/imunologia , Nanopartículas/química , Animais , Barreira Hematoencefálica/citologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cobre/química , Cobre/toxicidade , Dinoprostona/imunologia , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/imunologia , Interleucina-1beta/imunologia , Interleucina-2/imunologia , Nanopartículas/toxicidade , Nanopartículas/ultraestrutura , Fragmentos de Peptídeos/imunologia , Ratos , Fator de Necrose Tumoral alfa/imunologia
6.
Nanomedicine (Lond) ; 6(3): 437-48, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21542683

RESUMO

AIMS: This investigation compared the tumor distribution, efficacy, blood pharmacokinetic parameters and hematological alterations following treatment with chitosan/glyceryl-monooleate (GMO) nanostructures containing paclitaxel (PTX) to a conventional formulation of PTX (Taxol(®)) in BALB/c female mice. MATERIALS & METHODS: The tumor and blood concentrations of PTX were evaluated by HPLC and the pharmacokinetic parameters were determined through noncompartmental methods. Tumor development was evaluated by histopathological methods and hematological composition was monitored through differential white blood cells counts. RESULTS: Lower localized or intravenous doses of PTX-chitosan/GMO nanostructures significantly increased the antitumor activity of paclitaxel. The tumor distribution studies showed effective concentrations in the tumors with the chitosan/GMO formulation while systemic blood levels remained lower than after administration of the conventional formulation. CONCLUSION: Delivery systems consisting of chitosan/GMO and PTX are safe and effective administered locally (intratumorally) or intravenously.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Quitosana/farmacocinética , Glicerídeos/farmacocinética , Nanoestruturas/administração & dosagem , Neoplasias/tratamento farmacológico , Paclitaxel/farmacocinética , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Quitosana/administração & dosagem , Sistemas de Liberação de Medicamentos , Feminino , Glicerídeos/administração & dosagem , Contagem de Leucócitos , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/metabolismo , Paclitaxel/administração & dosagem
7.
Nanotoxicology ; 5(4): 479-92, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21175299

RESUMO

This report examined blood-brain barrier (BBB) related proinflammatory mediators and permeability changes in response to various sized gold nanoparticles (Au-NPs) (3, 5, 7, 10, 30 and 60 nm) in vitro using primary rat brain microvessel endothelial cells (rBMEC). The Au-NPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and laser Doppler velocimetry (LDV). The accumulation of Au-NPs was determined spectrophotometrically. The rBMEC cytotoxicity of Au-NPs was evaluated by cell proliferation assay (XTT) (concentration range 0.24-15.63 µg/cm², for 24 h). The time-dependent changes (0, 2, 4 and 8 h) of several proinflammatory mediators (IL-1ß, IL-2, TNFα and PGE2) were evaluated by ELISA. The smaller Au-NPs (3-7 nm) showed higher rBMEC accumulation compared to larger Au-NPs (10-60 nm), while only moderate decreased cell viability was observed with small Au-NPs (3 nm) at high concentrations (≥ 7.8 µg/cm²). Even though slight changes in cell viability were observed with small Au-NPs, the basal levels of the various proinflammatory mediators remained unchanged with all treatments except LPS (positive control). rBMEC morphology appeared unaffected 24 h after exposure to Au-NPs with only mild changes in fluorescein permeability indicating BBB integrity was unaltered. Together, these data suggest the responses of the cerebral microvasculature to Au-NPs have a significant relationship with the Au-NPs unique size-dependent physiochemical properties.


Assuntos
Barreira Hematoencefálica/citologia , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Ouro/farmacologia , Mediadores da Inflamação/metabolismo , Nanopartículas Metálicas/química , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Proliferação de Células , Forma Celular , Sobrevivência Celular , Células Cultivadas , Citocinas/metabolismo , Dinoprostona/metabolismo , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Fluoresceína , Ouro/farmacocinética , Fluxometria por Laser-Doppler , Luz , Microscopia Eletrônica de Transmissão , Microvasos/citologia , Microvasos/efeitos dos fármacos , Tamanho da Partícula , Ratos , Espalhamento de Radiação
8.
Toxicol Sci ; 118(1): 160-70, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20713472

RESUMO

The current report examines the interactions of silver nanoparticles (Ag-NPs) with the cerebral microvasculature to identify the involvement of proinflammatory mediators that can increase blood-brain barrier (BBB) permeability. Primary rat brain microvessel endothelial cells (rBMEC) were isolated from adult Sprague-Dawley rats for an in vitro BBB model. The Ag-NPs were characterized by transmission electron microscopy (TEM), dynamic light scattering, and laser Doppler velocimetry. The cellular accumulation, cytotoxicity (6.25-50 µg/cm(3)) and potential proinflammatory mediators (interleukin [IL]-1ß, IL-2, tumor necrosis factor [TNF] α, and prostaglandin E(2) [PGE(2)]) of Ag-NPs (25, 40, or 80 nm) were determined spectrophotometrically, cell proliferation assay (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) and ELISA. The results show Ag-NPs-induced cytotoxic responses at lower concentrations for 25 and 40 nm when compared with 80-nm Ag-NPs. The proinflammatory responses in this study demonstrate both Ag-NPs size and time-dependent profiles, with IL-1B preceding both TNF and PGE(2) for 25 nm. However, larger Ag-NPs (40 and 80 nm) induced significant TNF responses at 4 and 8 h, with no observable PGE(2) response. The increased fluorescein transport observed in this study clearly indicates size-dependent increases in BBB permeability correlated with the severity of immunotoxicity. Together, these data clearly demonstrate that larger Ag-NPs (80 nm) had significantly less effect on rBMEC, whereas the smaller particles induced significant effects on all the end points at lower concentrations and/or shorter times. Further, this study suggests that Ag-NPs may interact with the cerebral microvasculature producing a proinflammatory cascade, if left unchecked; these events may further induce brain inflammation and neurotoxicity.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Endotélio Vascular/efeitos dos fármacos , Inflamação/patologia , Nanopartículas Metálicas/toxicidade , Microvasos/efeitos dos fármacos , Prata/toxicidade , Animais , Biomarcadores/metabolismo , Velocidade do Fluxo Sanguíneo , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Permeabilidade Capilar/efeitos dos fármacos , Endotélio Vascular/metabolismo , Mediadores da Inflamação/metabolismo , Nanopartículas Metálicas/análise , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Microvasos/metabolismo , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Espalhamento de Radiação
9.
AAPS PharmSciTech ; 11(1): 392-401, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20238190

RESUMO

The objectives of this study are to enhance cellular accumulation of gemcitabine with chitosan/glyceryl monooleate (GMO) nanostructures, and to provide significant increase in cell death of human pancreatic cancer cells in vitro. The delivery system was prepared by a multiple emulsion solvent evaporation method. The nanostructure topography, size, and surface charge were determined by atomic force microscopy (AFM), and a zetameter. The cellular accumulation, cellular internalization and cytotoxicity of the nanostructures were evaluated by HPLC, confocal microscopy, or MTT assay in Mia PaCa-2 and BxPC-3 cells. The average particle diameter for 2% and 4% (w/w) drug loaded delivery system were 382.3 +/- 28.6 nm, and 385.2 +/- 16.1 nm, respectively with a surface charge of +21.94 +/- 4.37 and +21.23 +/- 1.46 mV. The MTT cytotoxicity dose-response studies revealed the placebo at/or below 1 mg/ml has no effect on MIA PaCa-2 or BxPC-3 cells. The delivery system demonstrated a significant decrease in the IC50 (3 to 4 log unit shift) in cell survival for gemcitabine nanostructures at 72 and 96 h post-treatment when compared with a solution of gemcitabine alone. The nanostructure reported here can be resuspended in an aqueous medium that demonstrate increased effective treatment compared with gemcitabine treatment alone in an in vitro model of human pancreatic cancer. The drug delivery system demonstrates capability to entrap both hydrophilic and hydrophobic compounds to potentially provide an effective treatment option in human pancreatic cancer.


Assuntos
Quitosana/uso terapêutico , Nanoestruturas , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/terapia , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Emulsões/farmacologia , Emulsões/uso terapêutico , Glicerídeos , Humanos , Concentração Inibidora 50 , Pâncreas/efeitos dos fármacos
10.
Drug Metab Dispos ; 34(6): 998-1003, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16554372

RESUMO

The present study quantitatively compared the drug efflux transport kinetics of 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and its fluorescent metabolite 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) in various blood-brain barrier (BBB) models. BCECF-AM was exposed to freshly isolated bovine brain microvessels (BBM), primary cultured bovine brain microvessel endothelial cells (BBMEC), and MDCK-MDR1 cells for 30 min in the presence or absence of the P-glycoprotein (P-gp) inhibitor N-(4-[2-(1,2,3,4-tetrahydro-6,7-dimethoxy-2-isoquinolinyl)ethyl]-phenyl)-9,10-dihydro-5-methoxy-9-oxo-4-acridine carboxamide (GF120918). P-gp transport kinetics were determined indirectly by calculating the difference in BCECF accumulation when P-gp was functional and completely inhibited by GF120918 (3.2 microM). Multidrug resistance-associated protein (MRP) transport kinetics were determined by measuring the amount of BCECF transported out of the cell over time. For P-gp-related transport, Km values for BCECF-AM were approximately the same in all three models (around 2 microM), whereas the Vmax was 4-fold greater in the BBM than in the BBMEC or MDCKII-MDR1 cells. For MRP-related transport, Km values for BCECF varied widely among the three BBB models with a rank order of MDCKII-MDR1 < BBMEC < BBM. Like P-gp, the Vmax of BCECF for MRP-related transport was overwhelmingly higher in the BBM compared with the cultured cells. Because differences in the expression of P-gp, MRP5, and MRP6 were observed in the various BBB models using reverse transcription-polymerase chain reaction techniques, the disparity in transport kinetics between the BBB models may be linked to variations in the amount or type of drug efflux transporters expressed in each model. The present study introduces a method of quantitatively evaluating drug efflux transport kinetics in the BBB.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Barreira Hematoencefálica/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Acridinas/farmacologia , Animais , Encéfalo/irrigação sanguínea , Bovinos , Linhagem Celular , Cães , Células Endoteliais/metabolismo , Fluoresceínas/análise , Fluoresceínas/metabolismo , Corantes Fluorescentes , Cinética , Microcirculação , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , RNA Mensageiro/metabolismo , Tetra-Hidroisoquinolinas/farmacologia , Transfecção
11.
J Pharm Sci ; 93(4): 932-42, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14999730

RESUMO

2',7'-Bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) is a fluorescent probe used to examine multidrug resistance-associated protein (MRP) transporter activity in cells. BCECF is introduced into the cell as the nonfluorescent membrane permeable acetoxymethyl ester, BCECF-AM, where it is hydrolyzed to the membrane impermeable BCECF. The lipophilic nature of BCECF-AM suggests it may be a substrate for other drug efflux transporters such as P-glycoprotein (P-gp) and the breast cancer resistance protein (BCRP). To assess the drug efflux transporter interactions of BCECF-AM and BCECF, accumulation studies were examined in various drug efflux-expressing cells. Inhibition of P-gp, BCRP, and/or MRP produced distinct changes in the time-dependent accumulation of BCECF in the cells. Treatment with GF120918 produced an immediate and sustained effect throughout the entire time course examined. Fumitremorgin C only affected BCECF accumulation at the early time points, whereas the impact of indomethacin on BCECF accumulation was observed only at the latter time points. Permeability studies in bovine brain microvessel endothelial cells indicated an increased basolateral-to-apical transport of BCECF, which could be reduced in the presence of either indomethacin or GF120918. These results indicate that the intracellular accumulation and transcellular permeability of BCECF are sensitive to a variety of drug efflux interactions. These results likely reflect an interaction of the ester form with P-gp and BCRP during the initial accumulation process, and an interaction of the free acid form with MRP after hydrolysis in the cell.


Assuntos
Proteínas de Transporte/metabolismo , Fluoresceínas/farmacocinética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Acridinas/farmacocinética , Animais , Anti-Inflamatórios não Esteroides/farmacocinética , Área Sob a Curva , Bovinos , Separação Celular , Células Cultivadas , Células Endoteliais/metabolismo , Corantes Fluorescentes/farmacocinética , Indicadores e Reagentes , Indometacina/farmacocinética , Permeabilidade , Espectrometria de Fluorescência , Tetra-Hidroisoquinolinas/farmacocinética
12.
J Pharm Sci ; 92(7): 1419-27, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12820146

RESUMO

The availability of microdialysis probes with higher molecular weight cutoff membranes has made it possible to measure larger molecular weight compounds like bioactive peptides and proteins. However, the higher molecular weight membrane cutoff allows for increased fluid loss from the probe, influencing both the physiology of the tissue compartment and analyte recovery. This study examined the ability of osmotic agents like bovine serum albumin (BSA) to offset the water loss from the microdialysis probe. In the presence of BSA, water loss from the microdialysis probe was minimized. Furthermore, addition of BSA to the perfusate produced significant increases in analyte recovery. Application of this technique to the measurement of bioactive macromolecules was examined using in vitro microdialysis of tumor necrosis factor (TNF) and interleukin-1 beta (IL-1B). The results of the present study suggest osmotic agents like BSA can prevent fluid loss from the microdialysis probe and improve analyte recovery.


Assuntos
Microdiálise/métodos , Soroalbumina Bovina/análise , Soroalbumina Bovina/metabolismo , Substâncias Macromoleculares , Microdiálise/instrumentação , Osmose/efeitos dos fármacos , Soroalbumina Bovina/química
13.
Life Sci ; 72(23): 2581-90, 2003 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-12672504

RESUMO

Common formulations of amphotericin-B include a deoxycholate colloidal suspension (d-Amph), an amphotericin-B lipid complex (Ablc), and a liposomal product (l-Amph). The clinical incidence of infusion related fever is highest with d-Amph, intermediate with Ablc, and lowest with l-Amph. In the present study, we measured the activation of cyclooxygenase-2 (COX-2) and subsequent release of prostaglandin E-2 (PgE-2) from brain microvessel endothelium treated with these three formulations of amphotericin-B. Primary cultured bovine brain microvessel endothelial cells (BBMEC) were exposed to d-Amph, Ablc and l-Amph at concentrations that can be achieved in the plasma of patients receiving the drug. Media samples from the cells were collected and analyzed for PgE-2. Release of PgE-2 from BBMEC monolayers treated with l-Amph was similar to cells receiving culture media alone. In contrast, Ablc and d-Amph caused significantly greater release of PgE-2 from BBMEC monolayers compared to controls receiving culture media alone. PgE-2 release after d-Amph treatment was similar in magnitude to that observed with bacterial lipopolysaccharide (LPS). Western blot analysis indicated significant induction of COX-2 expression in BBMEC following LPS, Ablc or d-Amph treatment. Furthermore, PgE-2 release following exposure of BBMEC monolayers to either LPS or the various amphotericin-B formulations was reduced by the addition of the selective COX-2 inhibitor, NS-398. These studies indicate that amphotericin-B induces COX-2 expression in brain microvessel endothelium resulting in release of fever producing PgE-2. The magnitude of PgE-2 release from BBMEC following exposure to various amphotericin-B formulations mirrors the clinical observations regarding amphotericin-B induced fever and serves as initial support for the clinical use of COX-2 inhibitors to reduce amphotericin-B fever.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Dinoprostona/metabolismo , Endotélio Vascular/efeitos dos fármacos , Isoenzimas/biossíntese , Prostaglandina-Endoperóxido Sintases/biossíntese , Animais , Encéfalo/irrigação sanguínea , Bovinos , Células Cultivadas , Química Farmacêutica , Meios de Cultivo Condicionados/química , Meios de Cultivo Condicionados/farmacologia , Ciclo-Oxigenase 2 , Dinoprostona/análise , Endotélio Vascular/enzimologia , Febre/induzido quimicamente , Febre/enzimologia , Lipopolissacarídeos/farmacologia , Microcirculação
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