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1.
Cancers (Basel) ; 15(11)2023 May 26.
Article in English | MEDLINE | ID: mdl-37296901

ABSTRACT

Breast cancer (BC) remains one of the most commonly diagnosed malignancies in women. There is increasing interest in the development of non-invasive screening methods. Volatile organic compounds (VOCs) emitted through the metabolism of cancer cells are possible novel cancer biomarkers. This study aims to identify the existence of BC-specific VOCs in the sweat of BC patients. Sweat samples from the breast and hand area were collected from 21 BC participants before and after breast tumor ablation. Thermal desorption coupled with two-dimensional gas chromatography and mass spectrometry was used to analyze VOCs. A total of 761 volatiles from a homemade human odor library were screened on each chromatogram. From those 761 VOCs, a minimum of 77 VOCs were detected within the BC samples. Principal component analysis showed that VOCs differ between the pre- and post-surgery status of the BC patients. The Tree-based Pipeline Optimization Tool identified logistic regression as the best-performing machine learning model. Logistic regression modeling identified VOCs that distinguish the pre-and post-surgery state in BC patients on both the breast and hand area with sensitivities close to 1. Further, Shapley additive explanations and the probe variable method identified the most important and pertinent VOCs distinguishing pre- and post-operative status which are mostly of distinct origin for the hand and breast region. Results suggest the possibility to identify endogenous metabolites linked to BC, hence proposing this innovative pipeline as a stepstone to discovering potential BC biomarkers. Large-scale studies in a multi-centered VOC analysis setting must be carried out to validate obtained findings.

2.
Oncology ; 96(2): 110-113, 2019.
Article in English | MEDLINE | ID: mdl-30278460

ABSTRACT

We developed a new transcutaneous method for breast cancer detection with dogs: 2 dogs were trained to sniff skin secretion samples on compresses that had been worn overnight by women on their breast, and to recognize a breast cancer sample among 4 samples. During the test, the dogs recognized 90.3% of skin secretion breast cancer samples. This proof-of-concept study opens new avenues for the development of a reliable cancer diagnostic tool integrating olfactory abilities of dogs.


Subject(s)
Breast Neoplasms/diagnosis , Dogs/physiology , Smell , Volatile Organic Compounds/analysis , Adult , Aged , Aged, 80 and over , Animals , Breast Neoplasms/metabolism , Female , Humans , Middle Aged , Skin/metabolism , Volatile Organic Compounds/metabolism
3.
Wounds ; 30(11): 337­344, 2018 08 23.
Article in English | MEDLINE | ID: mdl-30380523

ABSTRACT

INTRODUCTION: During the metabolic processes of malignant wounds, bacteria produce a large amount of volatile organic compounds (VOCs) that are responsible for malodors and may have a major impact on the patient's quality of life with a risk of isolation. OBJECTIVE: A translational study was conducted on 32 malignant breast wounds by combining the identification of bacterial strains present on wounds, the identification of VOCs produced by these bacterial strains, and sensory evaluation to assess odor intensity and quality of odorous bacteria. MATERIALS AND METHODS: Thirty-two patients with malignant breast cancer wounds > 10 cm2 at various stages of the disease (curative or palliative) were included in the protocol. Volatile organic compounds were collected from primary dressings by headspace solid-phase microextraction and then analyzed by gas chromatography separation coupled with a mass spectrometer detector analysis. Microbiological samplings were taken and analyzed on agar plates. The odors of selected bacteria were assessed by a panel of staff members. RESULTS: Proteus mirabilis and Fusobacterium necrophorum seem to produce the strongest and most typical malignant wound odor. The VOCs were analyzed and dimethyl disulfide, dimethyl trisulfide, phenol, indole, and 3-methylbutanal were found to be produced by bacteria generating the most typical wound odor. CONCLUSIONS: This study suggests the bacteria present in wounds may be responsible for odors. In addition, these findings could pave the way to engineer new types of dressings and to develop an evaluation method to assess their efficiency both quantitatively and qualitatively as well as improve quality of palliative care and comfort for women with malignant wounds.

4.
PLoS One ; 11(7): e0157670, 2016.
Article in English | MEDLINE | ID: mdl-27388901

ABSTRACT

Drug discovery efforts have focused on the tumor microenvironment in recent years. However, few studies have characterized the stroma component in patient-derived xenografts (PDXs) and genetically engineered mouse models (GEMs). In this study, we characterized the stroma in various models of breast cancer tumors in mice. We performed transcriptomic and flow cytometry analyses on murine populations for a series of 25 PDXs and the two most commonly used GEMs (MMTV-PyMT and MMTV-erBb2). We sorted macrophages from five models. We then profiled gene expression in these cells, which were also subjected to flow cytometry for phenotypic characterization. Hematopoietic cell composition, mostly macrophages and granulocytes, differed between tumors. Macrophages had a specific polarization phenotype related to their M1/M2 classification and associated with the expression of genes involved in the recruitment, invasion and metastasis processes. The heterogeneity of the stroma component of the models studied suggests that tumor cells modify their microenvironment to satisfy their needs. Our observations suggest that such models are of relevance for preclinical studies.


Subject(s)
Breast Neoplasms/physiopathology , Macrophages/cytology , Mammary Neoplasms, Animal/physiopathology , Animals , Cell Separation , Disease Models, Animal , Female , Flow Cytometry , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Mice , Mice, Transgenic , Neoplasm Metastasis , Phenotype , Receptor, ErbB-2/metabolism , Transcriptome , Tumor Microenvironment/genetics
5.
Soins ; (802): 42-4, 2016.
Article in French | MEDLINE | ID: mdl-26763567

ABSTRACT

While sensitivity to odours varies from one individual to another, bad smells can instinctively and uncontrollably induce nausea and revulsion. Different treatment strategies can be implemented. They consist in neutralising the odours, adding more pleasant smells and/or targeting the bacteria. The management of odours remains a complex problem without any universal or single solution. Odour control must not be used as a replacement for adapted hygiene and wound care.


Subject(s)
Occlusive Dressings , Odorants , Wounds and Injuries/therapy , Anti-Bacterial Agents/administration & dosage , Charcoal/therapeutic use , Exudates and Transudates , Humans , Oils, Volatile/administration & dosage
6.
Br J Cancer ; 114(2): 177-87, 2016 Jan 19.
Article in English | MEDLINE | ID: mdl-26695443

ABSTRACT

BACKGROUND: Oestrogen receptor-negative (ER-) breast cancer is intrinsically sensitive to chemotherapy. However, tumour response is often incomplete, and relapse occurs with high frequency. The aim of this work was to analyse the molecular characteristics of residual tumours and early response to chemotherapy in patient-derived xenografts (PDXs) of breast cancer. METHODS: Gene and protein expression profiles were analysed in a panel of ER- breast cancer PDXs before and after chemotherapy treatment. Tumour and stromal interferon-gamma expression was measured in xenografts lysates by human and mouse cytokine arrays, respectively. RESULTS: The analysis of residual tumour cells in chemo-responder PDX revealed a strong overexpression of IFN-inducible genes, induced early after AC treatment and associated with increased STAT1 phosphorylation, DNA-damage and apoptosis. No increase in IFN-inducible gene expression was observed in chemo-resistant PDXs upon chemotherapy. Overexpression of IFN-related genes was associated with human IFN-γ secretion by tumour cells. CONCLUSIONS: Treatment-induced activation of the IFN/STAT1 pathway in tumour cells is associated with chemotherapy response in ER- breast cancer. Further validations in prospective clinical trials will aim to evaluate the usefulness of this signature to assist therapeutic strategies in the clinical setting.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Breast Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Interferon-gamma/drug effects , Receptors, Estrogen/metabolism , STAT1 Transcription Factor/drug effects , Adaptor Proteins, Signal Transducing , Animals , Antigens/drug effects , Antigens/genetics , Antigens/metabolism , Blotting, Western , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Capecitabine/pharmacology , Carrier Proteins/drug effects , Carrier Proteins/genetics , Carrier Proteins/metabolism , Caspase 3/drug effects , Caspase 3/genetics , Caspase 3/metabolism , Caspase 7/drug effects , Caspase 7/genetics , Caspase 7/metabolism , Cisplatin/pharmacology , Cytokines/drug effects , Cytokines/genetics , Cytokines/metabolism , Cytoskeletal Proteins/drug effects , Cytoskeletal Proteins/genetics , Cytoskeletal Proteins/metabolism , Female , Gene Expression Profiling , Humans , Immunohistochemistry , In Situ Hybridization , Interferon-beta/drug effects , Interferon-beta/genetics , Interferon-beta/metabolism , Interferon-gamma/genetics , Interferon-gamma/metabolism , Intracellular Signaling Peptides and Proteins/drug effects , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Membrane Proteins/drug effects , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Mice, Nude , Mitochondrial Proteins/drug effects , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Myxovirus Resistance Proteins/drug effects , Myxovirus Resistance Proteins/genetics , Myxovirus Resistance Proteins/metabolism , Neoplasm Transplantation
7.
Mol Cancer Ther ; 14(9): 2035-48, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26116361

ABSTRACT

PI3K/AKT/mTOR signaling plays an important role in breast cancer. Its interaction with estrogen receptor (ER) signaling becomes more complex and interdependent with acquired endocrine resistance. Targeting mTOR combined with endocrine therapy has shown clinical utility; however, a negative feedback loop exists downstream of PI3K/AKT/mTOR. Direct blockade of AKT together with endocrine therapy may improve breast cancer treatment. AZD5363, a novel pan-AKT kinase catalytic inhibitor, was examined in a panel of ER(+) breast cancer cell lines (MCF7, HCC1428, T47D, ZR75.1) adapted to long-term estrogen deprivation (LTED) or tamoxifen (TamR). AZD5363 caused a dose-dependent decrease in proliferation in all cell lines tested (GI50 < 500 nmol/L) except HCC1428 and HCC1428-LTED. T47D-LTED and ZR75-LTED were the most sensitive of the lines (GI50 ∼ 100 nmol/L). AZD5363 resensitized TamR cells to tamoxifen and acted synergistically with fulvestrant. AZD5363 decreased p-AKT/mTOR targets leading to a reduction in ERα-mediated transcription in a context-specific manner and concomitant decrease in recruitment of ER and CREB-binding protein (CBP) to estrogen response elements located on the TFF1, PGR, and GREB1 promoters. Furthermore, AZD5363 reduced expression of cell-cycle-regulatory proteins. Global gene expression highlighted ERBB2-ERBB3, ERK5, and IGFI signaling pathways driven by MYC as potential feedback-loops. Combined treatment with AZD5363 and fulvestrant showed synergy in an ER(+) patient-derived xenograft and delayed tumor progression after cessation of therapy. These data support the combination of AZD5363 with fulvestrant as a potential therapy for breast cancer that is sensitive or resistant to E-deprivation or tamoxifen and that activated AKT is a determinant of response, supporting the need for clinical evaluation.


Subject(s)
Antineoplastic Agents, Hormonal/pharmacology , Drug Resistance, Neoplasm , Estradiol/analogs & derivatives , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Pyrimidines/pharmacology , Pyrroles/pharmacology , Receptors, Estrogen/metabolism , Animals , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cluster Analysis , Disease Models, Animal , Drug Synergism , Estradiol/pharmacology , Female , Fulvestrant , Gene Expression Profiling , Humans , Mice , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , Transcriptional Activation , Xenograft Model Antitumor Assays
8.
Ocul Oncol Pathol ; 1(3): 200-6, 2015 Apr.
Article in English | MEDLINE | ID: mdl-27171982

ABSTRACT

Retinoblastoma is a rare cancer that occurs during childhood. The goal of current and future therapeutic strategies is to conserve the eye and visual function without using external beam radiotherapy, which is known to increase the risk of secondary cancers in genetically predisposed patients. Multimodality therapy (usually intravenous but also intra-arterial and intravitreal chemotherapy, transpupillary thermotherapy, cryotherapy, or brachytherapy) has recently improved the eye salvage rate in retinoblastoma and has led to a decreased need for external beam radiotherapy. However, the treatment of advanced intraocular retinoblastoma remains a real challenge, especially in cases of vitreous and subretinal seeding. There is a need for alternative and less toxic therapies as well as for better ways to administer the drugs. Animal models are an integral part of preclinical research in the field of oncology. This paper describes the different xenograft rodent models published in the literature so far. We will also describe a new orthotopic xenografted retinoblastoma model in immunodeficient mice, which is suitable for preclinical assays. The xenograft model was established from tumor tissue obtained directly from surgical samples and closely mimics human retinoblastoma.

9.
PLoS One ; 9(11): e104227, 2014.
Article in English | MEDLINE | ID: mdl-25375638

ABSTRACT

PURPOSE: (1) To determine TweakR expression in human breast cancers (BC), (2) evaluate the antitumor effect of the anti-TweakR antibody PDL192, used alone or after chemotherapy-induced complete remission (CR), on patient-derived BC xenografts (PDX) and (3) define predictive markers of response. EXPERIMENTAL DESIGN: TweakR expression was analyzed by IHC on patients and PDXs BC samples. In vivo antitumor effect of PDL192 was evaluated on eight TweakR-positive BC PDXs alone or after complete remission induced by a combination of doxorubicin and cyclophosphamide. Using both responding and resistant PDX tumors after PDL192 administration, RT-QPCR were performed on a wide list of selected candidate genes to identify predictive markers of response. RESULTS: TweakR protein was expressed in about half of human BC samples. In vivo PDL192 treatment had significantly anti-tumor activity in 4 of 8 TweakR-positive BC PDXs, but no correlation between the expression level of the Tweak receptor and response to therapy was observed. PDL192 also significantly delayed tumor relapse after CR. Finally, an 8 gene signature was defined from sensitive and resistant PDXs. CONCLUSIONS: PDL192 was highly efficient in some BC PDXs. We found 8 genes that were differentially expressed in responding and resistant tumors and could constitute a gene expression signature which would need to be extended to other xenograft models for confirmation. These data confirm the therapeutic potential of TweakR targeting in BC and the possibility of prospectively selecting patients who might benefit from therapy.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Agents/therapeutic use , Breast Neoplasms/genetics , Gene Expression Regulation, Neoplastic/drug effects , Receptors, Tumor Necrosis Factor/genetics , Antibodies, Monoclonal, Humanized/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Cyclophosphamide/therapeutic use , Doxorubicin/therapeutic use , Female , Humans , Middle Aged , Receptors, Tumor Necrosis Factor/immunology , Receptors, Tumor Necrosis Factor/metabolism , TWEAK Receptor , Treatment Outcome
10.
Clin Cancer Res ; 20(16): 4314-25, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-24947930

ABSTRACT

PURPOSE: Patients with luminal breast cancer (LBC) often become endocrine resistant over time. We investigated the molecular changes associated with acquired hormonoresistances in patient-derived xenografts of LBC. EXPERIMENTAL DESIGN: Two LBC xenografts (HBCx22 and HBCx34) were treated with different endocrine treatments (ET) to obtain xenografts with acquired resistances to tamoxifen (TamR) and ovariectomy (OvaR). PI3K pathway activation was analyzed by Western blot analysis and IHC and responses to ET combined to everolimus were investigated in vivo. Gene expression analyses were performed by RT-PCR and Affymetrix arrays. RESULTS: HBCx22 TamR xenograft was cross-resistant to several hormonotherapies, whereas HBCx22 OvaR and HBCx34 TamR exhibited a treatment-specific resistance profile. PI3K pathway was similarly activated in parental and resistant xenografts but the addition of everolimus did not restore the response to tamoxifen in TamR xenografts. In contrast, the combination of fulvestrant and everolimus induced tumor regression in vivo in HBCx34 TamR, where we found a cross-talk between the estrogen receptor (ER) and PI3K pathways. Expression of several ER-controlled genes and ER coregulators was significantly changed in both TamR and OvaR tumors, indicating impaired ER transcriptional activity. Expression changes associated with hormonoresistance were both tumor and treatment specific and were enriched for genes involved in cell growth, cell death, and cell survival. CONCLUSIONS: PDX models of LBC with acquired resistance to endocrine therapies show a great diversity of resistance phenotype, associated with specific deregulations of ER-mediated gene transcription. These models offer a tool for developing anticancer therapies and to investigate the dynamics of resistance emerging during pharmacologic interventions. Clin Cancer Res; 20(16); 4314-25. ©2014 AACR.


Subject(s)
Antineoplastic Agents, Hormonal/pharmacology , Breast Neoplasms/drug therapy , Drug Resistance, Neoplasm , Estrogen Receptor alpha/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Receptor, ErbB-2/metabolism , Tamoxifen/pharmacology , Animals , Apoptosis/drug effects , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Blotting, Western , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Cycle/drug effects , Cell Proliferation/drug effects , Estrogen Receptor alpha/genetics , Female , Humans , Immunoenzyme Techniques , Mice , Mice, Nude , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Receptor, ErbB-2/genetics , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
11.
ACS Nano ; 8(6): 5715-24, 2014 Jun 24.
Article in English | MEDLINE | ID: mdl-24853551

ABSTRACT

Few approaches are available to investigate the potential of carbon nanotubes (CNTs) to translocate to distant organs following lung exposure, although this needs to be taken into account to evaluate potential CNT toxicity. Here, we report a method for quantitative analysis of the tissue biodistribution of multiwalled CNTs (MWCNTs) as a function of time. The method relies on the use of in situ (14)C-radiolabeled MWCNTs and combines radioimaging of organ tissue sections to ex vivo analysis of MWCNTs by electron microscopy. To illustrate the usefulness of this approach, mice were exposed to a single dose of 20 µg of (14)C-labeled MWCNTs by pharyngeal aspiration and were subjected to a follow-up study over one year. After administration, MWCNT were cleared from the lungs, but there was a concomitant relocation of these nanoparticles to distant organs starting throughout the follow-up period, with nanoparticle accumulation increasing with time. After one year, accumulation of MWCNTs was documented in several organs, including notably the white pulp of the spleen and the bone marrow. This study shows that the proposed method may be useful to complement other approaches to address unresolved toxicological issues associated with CNTs. These issues include their persistence over long periods in extrapulmonary organs, the relationship between the dose and the extent of translocation, and the effects of "safety by design" on those processes. The same approach could be used to study the translocation propensity of other nanoparticles containing carbon atoms.


Subject(s)
Carbon Radioisotopes/chemistry , Lung/drug effects , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Air , Animals , Bone Marrow/drug effects , Chromatography, Thin Layer , Dose-Response Relationship, Drug , Female , Lung/radiation effects , Mice , Mice, Inbred BALB C , Microscopy, Electron, Transmission , Respiratory Aspiration , Scintillation Counting , Spleen/drug effects , Tissue Distribution
12.
Lab Invest ; 93(5): 611-21, 2013 May.
Article in English | MEDLINE | ID: mdl-23459372

ABSTRACT

Metabolic adaptations and changes in the expression of nutrient transporters are known to accompany tumorigenic processes. Nevertheless, in the context of solid tumors, studies of metabolism are hindered by a paucity of tools allowing the identification of cell surface transporters on individual cells. Here, we developed a method for the dissociation of human breast cancer tumor xenografts combined with quantification of cell surface markers, including metabolite transporters. The expression profiles of four relevant nutrient transporters for cancer cells' metabolism, Glut1, ASCT2, PiT1 and PiT2 (participating to glucose, glutamine and inorganic phosphate, respectively), as detected by new retroviral envelope glycoprotein-derived ligands, were distinctive of each tumor, unveiling underlying differences in metabolic pathways. Our tumor dissociation procedure and nutrient transporter profiling technology provides opportunities for future basic research, clinical diagnosis, prognosis and evaluation of therapeutic responses, as well as for drug discovery and development.


Subject(s)
Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Flow Cytometry/methods , Membrane Transport Proteins/metabolism , Analysis of Variance , Animals , Cell Line, Tumor , Cell Membrane/metabolism , Cell Survival/physiology , Female , Humans , Hyaluronan Receptors/genetics , Hyaluronan Receptors/metabolism , Immunohistochemistry/methods , Mice , Mice, Nude , Neoplasm Transplantation , Reproducibility of Results , Transplantation, Heterologous
13.
Clin Cancer Res ; 18(14): 3934-41, 2012 Jul 15.
Article in English | MEDLINE | ID: mdl-22645051

ABSTRACT

PURPOSE: To develop a molecular tool to detect circulating tumor-derived DNA (ctDNA) in the plasma from patients with uveal melanoma as a marker of tumor burden and monitor treatment efficacy. EXPERIMENTAL DESIGN: A real-time PCR was developed on the basis of bidirectional pyrophosphorolysis-activated polymerization (bi-PAP) for the quantification of ctDNA using 3'blocked primer pairs specific for the 3 recurrent mutually exclusive mutations of Gα subunits GNAQ and GNA11. RESULTS: Sensitivity and specificity of bi-PAP were assessed on serial dilutions of tumor DNA in normal DNA for the 3 recurrent mutations. Each assay could detect a single mutated molecule per reaction, whereas 10(4) copies of normal DNA were not detected. The ctDNA was readily detected in plasma of mice bearing uveal melanoma xenografts in amounts proportional to circulating human DNA. Finally, plasma was almost always found positive (20 of 21 tested patients) in a prospective analysis of patients with metastatic uveal melanoma. CONCLUSIONS: Bi-PAP assays detect and quantify ctDNA in patients with metastatic uveal melanoma. A prospective study is ongoing to assess the clinical usefulness of ctDNA level in uveal melanoma.


Subject(s)
DNA/blood , Melanoma , Neoplasms, Experimental , Neoplastic Cells, Circulating , Real-Time Polymerase Chain Reaction/methods , Uveal Neoplasms , Animals , Humans , Melanoma/blood , Melanoma/secondary , Mice , Neoplasms, Experimental/blood , Neoplasms, Experimental/secondary , Sensitivity and Specificity , Uveal Neoplasms/blood , Uveal Neoplasms/secondary
14.
Am J Vet Res ; 71(7): 773-9, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20594079

ABSTRACT

OBJECTIVE: To investigate the role of superoxide anions in the lipopolysaccharide (LPS)-induced impairment of beta-adrenoceptor-mediated equine digital vein (EDV) vasodilation. SAMPLE POPULATION: EDVs isolated from forelimbs of 24 healthy adult horses. PROCEDURES: Endothelium-intact or endothelium-denuded EDV rings were incubated with or without LPS (10 microg/mL) of Escherichia coli (O55:B5) for 4 hours. Cumulative concentration-relaxation curves resulting from administration of isoprenaline, a nonselective beta-adrenoceptor agonist, or from administration of SR 58611A, a selective beta(3)-adrenoceptor agonist, were recorded in phenylephrine-preconstricted EDVs in the absence or the presence of superoxide dismutase (200 U/mL). Isoprenaline-induced relaxation was also evaluated with or without the cyclooxygenase inhibitors indomethacin (10 microM) and NS-398 (10 microM). RESULTS: Isoprenaline and SR 58611A induced concentration-dependent relaxation of EDV rings, which was inhibited by LPS exposure. Superoxide dismutase abolished the inhibitory effect of LPS on the isoprenaline- and SR 58611A-mediated relaxation. Pretreatment of the LPS-treated EDVs with indomethacin or NS-398 restored the isoprenaline-mediated relaxation and abolished the LPS-induced impairment to a similar extent as superoxide dismutase. CONCLUSIONS AND CLINICAL RELEVANCE: Results supported a role of superoxide anions in the LPS-induced impairment of beta-adrenoceptor-mediated EDV vasodilation. The LPS-induced oxidative stress in EDVs may contribute to vascular dysfunctions associated with laminitis in horses.


Subject(s)
Adrenergic beta-Agonists/pharmacology , Endothelium, Vascular/physiology , Endotoxins/toxicity , Isoproterenol/pharmacology , Receptors, Adrenergic, beta/physiology , Vasodilation/drug effects , Veins/physiology , Acetylcholine/pharmacology , Animals , Endothelium, Vascular/drug effects , Forelimb/blood supply , Forelimb/drug effects , Forelimb/physiology , Horses , Nitroprusside/pharmacology , Receptors, Adrenergic, beta/drug effects , Tetrahydronaphthalenes/pharmacology , Toes/blood supply , Veins/drug effects
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