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1.
J Vis Exp ; (165)2020 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-33226024

RESUMO

The rat orthotopic liver transplantation (OLT) model is a powerful tool to study acute and chronic rejection. However, it is not a complete representation of human liver transplantation due to the absence of arterial reconnection. Described here is a modified transplantation procedure that includes the incorporation of hepatic artery (HA) reconnection, leading to a marked improvement in transplant outcomes. With a mean anhepatic time of 12 min and 14 s, HA reconnection results in improved perfusion of the transplanted liver and an increase in long-term recipient survival from 37.5% to 88.2%. This protocol includes the use of 3D-printed cuffs and holders to connect the portal vein and infrahepatic inferior vena cava. It can be implemented for studying multiple aspects of liver transplantation, from immune response and infection to technical aspects of the procedure. By incorporating a simple and practical method for arterial reconnection using a microvascular technique, this modified rat OLT protocol closely mimics aspects of human liver transplantation and will serve as a valuable and clinically relevant research model.


Assuntos
Rejeição de Enxerto/prevenção & controle , Artéria Hepática/cirurgia , Hepatopatias/cirurgia , Transplante de Fígado/veterinária , Veia Porta/cirurgia , Complicações Pós-Operatórias/prevenção & controle , Animais , Transplante de Fígado/métodos , Masculino , Ratos , Ratos Endogâmicos Lew
2.
Artigo em Inglês | MEDLINE | ID: mdl-33233350

RESUMO

Impaired muscle recovery (size and strength) following a disuse period commonly occurs in older adults. Many of these individuals are not able to adequately exercise due to pain and logistic barriers. Thus, nutritional and pharmacological therapeutics, that are translatable, are needed to promote muscle recovery following disuse in older individuals. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be a suitable therapeutic target due to pleiotropic regulation of skeletal muscle. This review focuses on nutritional and pharmacological interventions that target PGC-1α and related Sirtuin 1 (SIRT1) and 5' AMP-activated protein kinase (AMPKα) signaling in muscle and thus may be rapidly translated to prevent muscle disuse atrophy and promote recovery. In this review, we present several therapeutics that target PGC-1α in skeletal muscle such as leucine, ß-hydroxy-ß-methylbuyrate (HMB), arginine, resveratrol, metformin and combination therapies that may have future application to conditions of disuse and recovery in humans.


Assuntos
Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Envelhecimento/metabolismo , Animais , Músculo Esquelético/irrigação sanguínea , Atrofia Muscular/patologia , Ratos , Ratos Endogâmicos Lew , Sirtuína 1
3.
Acta Cir Bras ; 35(10): e202001004, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33237176

RESUMO

PURPOSE: To modify a surgical catheterization method using the bent needle introducer in small animals. METHODS: Eight-week-old male Lewis rats were used in the study. A needle introducer was created by bending a 21G injection needle at 45°. The bent needle introducer was used for catheter insertion into the left femoral artery of the rats under anesthesia. As a control, a catheter was directly inserted into the blood vessel without the introducer. The insertion time of each method was measured. Blood pressure and heart rate were measured 24 h after catheter insertion using the telemetry system. RESULTS: Using the introducer, the catheter was successfully inserted within a short time in all rats. Without the introducer, a longer duration was required for catheter insertion. The frequency of the insertion with no catheter-based errors with the introducer tended to be higher than that without the introducer. The mean arterial pressure and heart rate 24 h after catheter insertion in each group were almost the same. CONCLUSIONS: We developed a surgical catheterization method using the introducer in small animals. This could potentially reduce the frequency of the insertion with catheter-based errors and insertion time.


Assuntos
Cateterismo , Artéria Femoral , Animais , Artéria Femoral/cirurgia , Masculino , Agulhas , Ratos , Ratos Endogâmicos Lew
4.
Sci Rep ; 10(1): 20007, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33203975

RESUMO

We applied transfer learning using Convolutional Neuronal Networks to high resolution X-ray phase contrast computed tomography datasets and tested the potential of the systems to accurately classify Computed Tomography images of different stages of two diseases, i.e. osteoarthritis and liver fibrosis. The purpose is to identify a time-effective and observer-independent methodology to identify pathological conditions. Propagation-based X-ray phase contrast imaging WAS used with polychromatic X-rays to obtain a 3D visualization of 4 human cartilage plugs and 6 rat liver samples with a voxel size of 0.7 × 0.7 × 0.7 µm3 and 2.2 × 2.2 × 2.2 µm3, respectively. Images with a size of 224 × 224 pixels are used to train three pre-trained convolutional neuronal networks for data classification, which are the VGG16, the Inception V3, and the Xception networks. We evaluated the performance of the three systems in terms of classification accuracy and studied the effect of the variation of the number of inputs, training images and of iterations. The VGG16 network provides the highest classification accuracy when the training and the validation-test of the network are performed using data from the same samples for both the cartilage (99.8%) and the liver (95.5%) datasets. The Inception V3 and Xception networks achieve an accuracy of 84.7% (43.1%) and of 72.6% (53.7%), respectively, for the cartilage (liver) images. By using data from different samples for the training and validation-test processes, the Xception network provided the highest test accuracy for the cartilage dataset (75.7%), while for the liver dataset the VGG16 network gave the best results (75.4%). By using convolutional neuronal networks we show that it is possible to classify large datasets of biomedical images in less than 25 min on a 8 CPU processor machine providing a precise, robust, fast and observer-independent method for the discrimination/classification of different stages of osteoarthritis and liver diseases.


Assuntos
Cartilagem/patologia , Hepatopatias/patologia , Animais , Aprendizado de Máquina , Masculino , Redes Neurais de Computação , Osteoartrite/patologia , Ratos , Ratos Endogâmicos Lew , Tomografia Computadorizada por Raios X/métodos , Raios X
5.
J Vis Exp ; (164)2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33104075

RESUMO

Peripheral and central nerve injuries are mostly studied in rodents, especially rats, given the fact that these animal models are both cost-effective and a lot of comparative data has been published in the literature. This includes a multitude of assessment methods to study functional recovery following nerve injury and repair. Besides evaluation of nerve regeneration by means of histology, electrophysiology, and other in vivo and in vitro assessment techniques, functional recovery is the most important criterion to determine the degree of neural regeneration. Automated gait analysis allows recording of a vast quantity of gait-related parameters such as Paw Print Area and Paw Swing Speed as well as measures of inter-limb coordination. Additionally, the method provides digital data of the rats' paws after neuronal damage and during nerve regeneration, adding to our understanding of how peripheral and central nervous injuries affect their locomotor behavior. Besides the predominantly used sciatic nerve injury model, other models of peripheral nerve injury such as the femoral nerve can be studied by means of this method. In addition to injuries of the peripheral nervous systems, lesions of the central nervous system, e.g., spinal cord contusion can be evaluated. Valid and reproducible data assessment is strongly dependent on meticulous adjustment of the hard- and software settings prior to data acquisition. Additionally, proper training of the experimental animals is of crucial importance. This work aims to illustrate the use of computerized automated gait analysis to assess functional recovery in different animal models of peripheral nerve injury as well as spinal cord contusion injury. It also emphasizes the method's limitations, e.g., evaluation of nerve regeneration in rats with sciatic nerve neurotmesis due to limited functional recovery. Therefore, this protocol is thought to help researchers interested in peripheral and central nervous injuries to assess functional recovery in rodent models.


Assuntos
Análise da Marcha/métodos , Traumatismos dos Nervos Periféricos/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Animais , Autoenxertos , Automação , Modelos Animais de Doenças , Nervo Femoral/patologia , Nervo Femoral/fisiopatologia , Marcha/fisiologia , Membro Posterior/fisiopatologia , Abrigo para Animais , Masculino , Regeneração Nervosa/fisiologia , Ratos Endogâmicos Lew , Ratos Sprague-Dawley , Nervo Isquiático/patologia , Nervo Isquiático/fisiopatologia , Neuropatia Ciática/fisiopatologia , Vértebras Torácicas/patologia , Vértebras Torácicas/fisiopatologia
6.
Am J Physiol Renal Physiol ; 319(5): F796-F808, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32924545

RESUMO

To investigate T helper type 17 (Th17) cells in the setting of acute kidney injury, the gene encoding the master regulator of Th17 cell differentiation, that is, RAR-related orphan receptor-γ (RORγT), was mutated in Lewis rats using CRISPR/Cas9 technology. In response to 40 min of bilateral renal ischemia-reperfusion (I/R), RAR-related orphan receptor C (Rorc)-/- rats were resistant to injury relative to wild-type Rorc+/+ rats. This protection was associated with inhibition of IL-17 expression and reduced infiltration of CD4+ cells, CD8+ cells, B cells, and macrophages. To evaluate the effect of Th17 cells on repair, ischemia was increased to 50 min in Rorc-/- rats. This maneuver equalized the initial level of injury in Rorc-/- and Rorc+/+ rats 1 to 2 days post-I/R based on serum creatinine values. However, Rorc-/- rats, but not Rorc+/+ rats, failed to successfully recover renal function and had high mortality by 4 days post-I/R. Histological assessment of kidney tubules showed evidence of repair by day 4 post-I/R in Rorc+/+ rats but persistent necrosis and elevated cell proliferation in Rorc-/- rats. Adoptive transfer of CD4+ cells from the spleen of Rorc+/+ rats or supplementation of exogenous rIL-17 by an osmotic minipump improved renal function and survival of Rorc-/- rats following 50 min of I/R. This was associated with a relative decrease in the number of M1-type macrophages and a relative increase in the percentage of T regulatory cells. Taken together, these data suggest that Th17 cells have both a deleterious and a beneficial role in kidney injury and recovery, contributing to early postischemic injury and inflammation but also possibly being critical in the resolution of inflammation during kidney repair.


Assuntos
Rim/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Traumatismo por Reperfusão/metabolismo , Linfócitos T Reguladores/metabolismo , Lesão Renal Aguda/metabolismo , Lesão Renal Aguda/patologia , Animais , Inflamação/metabolismo , Isquemia/metabolismo , Mutação/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Ratos , Ratos Endogâmicos Lew , Recuperação de Função Fisiológica , Traumatismo por Reperfusão/patologia , Células Th17
7.
PLoS One ; 15(9): e0238600, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32947606

RESUMO

Vitamin A and its metabolites are key regulators of the development of adipose tissue and associated metabolic complications. The aim of this study was to determine the effect of high fat diet and 13-cis retinoic acid (13 cRA) application on metabolic parameters, adipogenic and inflammatory indicators in female Lewis rats. Female rats of Lewis strain were fed standard laboratory diet (STD) and high fat diet (HFD, 45% of saturated fatty acids) during 30 days. The groups were divided into additional 3 groups (6 rats each): two experimental groups that received 13 cRA orally on a daily basis during 30 days (7.5 mg/kg and 15 mg/kg, respectively) and the control group that was given sunflower oil. Animals were sacrificed after 60 days. Feeding of Lewis rats with chronic HFD diet with 13 cRA supplementation increased weight gain, adiposity index, dyslipidaemia, hyperleptinaemia, insulin resistance, VLDL concentrations, oxidative stress and atherogenic indices. Administration of 13 cRA in Lewis rats fed STD did not change the weight of the animals, but it slightly increased the atherogenic parameters. 13 cRA and HFD affect metabolic parameters, glucose and lipid metabolism in Lewis rats and its administration has a completely different effect on metabolism in rats fed STD, highlighting the complex role of vitamin A supplementation in obesity. Other factors, such as genetics, age, sex, adipose tissue distribution, also must be taken into consideration.


Assuntos
Dieta Hiperlipídica , Glucose/metabolismo , Isotretinoína/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Animais , Feminino , Resistência à Insulina , Isotretinoína/administração & dosagem , Obesidade/metabolismo , Ratos Endogâmicos Lew , Ganho de Peso/efeitos dos fármacos
8.
Microvasc Res ; 132: 104070, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32890600

RESUMO

PURPOSE: Subcutaneous tissue is a promising site for cell transplantation; advantages include minimally invasive procedures and easy post-transplant monitoring. However, limited vascularity is the major known challenge. To address this challenge, a prevascularized graft bed is prepared in recipients. We aimed to establish an improved, clinically applicable approach to promote prevascularization of the subcutaneous graft bed prior to cell transplantation. METHODS: We applied a conventional prevascularization approach by subcutaneously implanting nylon discs into the backs of Lewis rats. After disc implantation, we treated rats with or without intermittent normobaric 100% oxygen inhalation (1 h, twice a day, for consecutive 7 days). We used histology to compare vascular density between the oxygen-treated or control groups. To assess the functional effects of prevascularization, we transplanted three hundred islets isolated from luciferase-transgenic Lewis rats into the oxygen-treated or control wild type Lewis recipients, then used bioluminescence imaging to track engraftment for 4 weeks. RESULTS: Oxygen treatment significantly augmented prevascularization in the subcutaneous site compared to controls. Islet transplantation into prevascularized graft beds demonstrated significant improvement in engraftment efficiency in oxygen-treated recipients compared to controls at 2-4 weeks post-transplantation. CONCLUSION: Combining intermittent normobaric 100% oxygen inhalation with a conventional vascularization approach promotes a functional vasculature within a week. A simple approach using normobaric oxygen has the potential for translation into clinical application in subcutaneous site cell transplantations.


Assuntos
Sobrevivência de Enxerto , Transplante das Ilhotas Pancreáticas , Neovascularização Fisiológica , Oxigênio/administração & dosagem , Tela Subcutânea/irrigação sanguínea , Condicionamento Pré-Transplante/métodos , Administração por Inalação , Animais , Esquema de Medicação , Ratos Endogâmicos Lew , Fatores de Tempo
9.
PLoS One ; 15(7): e0235702, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32634159

RESUMO

Rheumatoid arthritis (RA) is accompanied by pain, inflammation and muscle weakness. Skeletal muscle inflammation and inactivity are independently associated with muscle insulin resistance and atrophy. Our objective was to identify early molecular and biochemical markers in muscle from a rodent model of RA relative to control and subsequently identify commonality in muscle gene expression between this model and muscle from RA patients. Pain behaviour and locomotor activity were measured in a collagen-induced arthritis (CIA) model of RA (n = 9) and control (n = 9) rats. Energy substrates and metabolites, total alkaline-soluble protein:DNA ratio and mRNA abundance of 46 targeted genes were also determined in Extensor digitorum longus muscle. Expression of targeted mRNAs was quantified in Vastus Lateralis muscle from RA patients (n = 7) and healthy age-matched control volunteers (n = 6). CIA rats exhibited pain behaviour (p<0.01) and reduced activity (p<0.05) compared to controls. Muscle glycogen content was less (p<0.05) and muscle lactate content greater (p<0.01) in CIA rats. The bioinformatics analysis of muscle mRNA abundance differences from the control, predicted the activation of muscle protein metabolism and inhibition of muscle carbohydrate and fatty acid metabolism in CIA rats. Compared to age-matched control volunteers, RA patients exhibited altered muscle mRNA expression of 8 of the transcripts included as targets in the CIA model of RA. In conclusion, muscle energy metabolism and metabolic gene expression were altered in the CIA model, which was partly corroborated by targeted muscle mRNA measurements in RA patients. This research highlights the negative impact of RA on skeletal muscle metabolic homeostasis.


Assuntos
Artrite Reumatoide/complicações , Músculo Esquelético/metabolismo , Doenças Musculares/etiologia , Idoso , Animais , Artrite Experimental/metabolismo , Artrite Reumatoide/metabolismo , Biomarcadores , Modelos Animais de Doenças , Feminino , Glicogênio/metabolismo , Humanos , Inflamação , Locomoção , Pessoa de Meia-Idade , Doenças Musculares/metabolismo , Mialgia/etiologia , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos Lew , Transcriptoma
10.
PLoS One ; 15(7): e0235965, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32701960

RESUMO

Secondary lymphedema (SL)is a frequent and devastating complication of modern oncological therapy and filarial infections. A lack of a reliable preclinical model to investigate the underlying mechanism of clinical stage progression has limited the development of new therapeutic strategies. Current first line treatment has shown to be merely symptomatic and relies on lifetime use of compression garments and decongestive physiotherapy. In this study, we present the development of a secondary lymphedema model in 35 rats using pre- and intraoperative fluorescence-guided mapping of the lymphatics and microsurgical induction. In contrast to the few models reported so far, we decided to avoid the use of radiation for lymphedema induction. It turned out, that the model is nearly free of complications and capable of generating a statistically significant limb volume increase by water displacement measurements, sustained for at least 48 days. A translational, accurate lymphatic dysfunction was visualized by a novel VIS-NIR X-ray ICG-Clearance-Capacity imaging technology. For the first-time SL stage progression was validated by characteristic histological alterations, such as subdermal mast cell infiltration, adipose tissue deposition, and fibrosis by increased skin collagen content. Immunofluorescence confocal microscopy analysis suggested that stage progression is related to the presence of a characteristic α SMA+/HSP-47+/vimentin+ fibroblast subpopulation phenotype. These findings demonstrate that the in-vivo model is a reliable and clinically relevant SL model for the development of further secondary lymphedema therapeutic strategies and the analysis of the veiled molecular mechanisms of lymphatic dysfunction.


Assuntos
Corantes Fluorescentes/química , Linfedema/patologia , Microcirurgia/efeitos adversos , Actinas/metabolismo , Animais , Colágeno/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Verde de Indocianina/química , Linfedema/etiologia , Microscopia de Fluorescência , Ratos , Ratos Endogâmicos Lew , Pele/patologia , Vimentina/metabolismo
11.
PLoS One ; 15(6): e0234691, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555658

RESUMO

BACKGROUND: Therapeutic ultrasound (US) is a promising physical therapy modality for peripheral nerve regeneration. However, it is necessary to identify the most effective US parameters and clarify the underlying mechanisms before its clinical application. The intensity of US is one of the most important parameters. However, the optimum intensity for the promotion of peripheral nerve regeneration has yet to be determined. OBJECTIVES: To identify the optimum intensity of US necessary for the promotion of peripheral nerve regeneration after crush injuries in rats and to clarify the underlying mechanisms of US by mRNA expression analysis. METHODS: We inflicted sciatic nerve crush injuries on adult Lewis rats and performed ultrasound irradiation using 4 different US intensities: 0 (sham stimulation), 30, 140, and 250 mW/cm2 with frequency (5 days/week) and duration (5 min/day). We evaluated peripheral nerve regeneration by quantitative real-time PCR one week after injury. Histomorphometric analyses and motor function analysis were evaluated 3 weeks after injury. RESULTS: US stimulation enhanced re-myelination as well as sprouting of axons, especially at an intensity of 140 mW/cm2. mRNA expression revealed that US suppressed the expression of the inflammatory cytokines TNF and IL-6 and the axonal growth inhibitors SEMA3A and GSK3ß. CONCLUSIONS: An intensity of 140 mW/cm2 was optimal to support regeneration of the sciatic nerve after a crush injury in rats by, in part, the suppression of pro-inflammatory and nerve growth inhibitor gene expression.


Assuntos
Regulação da Expressão Gênica , Glicogênio Sintase Quinase 3 beta/genética , Regeneração Nervosa , Traumatismos dos Nervos Periféricos/fisiopatologia , Traumatismos dos Nervos Periféricos/terapia , Semaforina-3A/genética , Terapia por Ultrassom , Animais , Citocinas/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Mediadores da Inflamação/metabolismo , Masculino , Bainha de Mielina/metabolismo , Compressão Nervosa , Regeneração Nervosa/genética , Traumatismos dos Nervos Periféricos/diagnóstico por imagem , Traumatismos dos Nervos Periféricos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Endogâmicos Lew , Nervo Isquiático/lesões , Nervo Isquiático/patologia , Nervo Isquiático/fisiopatologia , Nervo Isquiático/ultraestrutura , Semaforina-3A/metabolismo
12.
PLoS One ; 15(6): e0234493, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520953

RESUMO

Multiple sclerosis (MS) is a neurodegenerative disease characterized by demyelination and inflammation. Dysregulated lipid metabolism and mitochondrial dysfunction are hypothesized to play a key role in MS. Carnitine Palmitoyl Transferase 1 (CPT1) is a rate-limiting enzyme for beta-oxidation of fatty acids in mitochondria. The therapeutic effect of pharmacological CPT1 inhibition with etomoxir was investigated in rodent models of myelin oligodendrocyte glycoprotein- and myelin basic protein-induced experimental autoimmune encephalitis (EAE). Mice receiving etomoxir showed lower clinical score compared to placebo, however this was not significant. Rats receiving etomoxir revealed significantly lower clinical score and lower body weight compared to placebo group. When comparing etomoxir with interferon-ß (IFN-ß), IFN-ß had no significant therapeutic effects, whereas etomoxir treatment starting at day 1 and 5 significantly improved the clinical scores compared to the IFN-ß and the placebo group. Immunohistochemistry and image assessments of brain sections from rats with EAE showed higher myelination intensity and decreased expression of CPT1A in etomoxir-treated rats compared to placebo group. Moreover, etomoxir mediated increased interleukin-4 production and decreased interleukin-17α production in activated T cells. In conclusion, CPT1 is a key protein in the pathogenesis of EAE and MS and a crucial therapeutic target for the treatment.


Assuntos
Carnitina O-Palmitoiltransferase/antagonistas & inibidores , Encefalomielite Autoimune Experimental/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Compostos de Epóxi/uso terapêutico , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Carnitina O-Palmitoiltransferase/metabolismo , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Compostos de Epóxi/administração & dosagem , Compostos de Epóxi/farmacologia , Feminino , Interleucina-17/genética , Interleucina-17/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Bainha de Mielina/metabolismo , Ratos , Ratos Endogâmicos Lew
13.
Sci Rep ; 10(1): 9135, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32499488

RESUMO

Gentle tactile stimuli have been shown to play an important role in the establishment and maintenance of affiliative social interactions. Oxytocin has also been shown to have similar actions. We investigated the effects of gentle stroking on affiliative relationships between humans and rats and the effects of gentle stroking on activation of oxytocin neurons. Male rats received 5-min stroking stimuli from an experimenter every other day for 4 weeks between 3 and 6 weeks of age (S3-6 group), for 4 weeks between 7 and 10 weeks of age (S7-10 group), or for 8 weeks between 3 and 10 weeks of age (S3-10 group). Control rats did not receive stroking stimuli. Rats in the S7-10 and S3-10 groups emitted 50-kHz calls, an index of positive emotion, more frequently during stroking stimuli. Rats in the S3-6, S7-10, and S3-10 groups showed affiliative behaviors toward the experimenter. Oxytocin neurons in the hypothalamic paraventricular nucleus of rats in the S3-6, S7-10, and S3-10 groups were activated following stroking stimuli. These findings revealed that post-weaning repeated stroking stimuli induce an affiliative relationship between rats and humans and activation of oxytocin neurons.


Assuntos
Neurônios/metabolismo , Estimulação Física , Animais , Comportamento Animal , Humanos , Masculino , Núcleo Hipotalâmico Paraventricular/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Endogâmicos Lew , Tato , Vocalização Animal
14.
Invest Ophthalmol Vis Sci ; 61(6): 23, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32526032

RESUMO

Purpose: The present study was conducted to examine the profile of oxidized phospholipids (OxPLs) in uveitis using rat model and clinical specimens, and to elucidate the role of macrophages in the metabolism of OxPLs. Methods: Lewis rats were immunized with a bovine interphotoreceptor retinoid- binding protein (bIRBP) peptide with complete Freund's adjuvant (CFA) to induce experimental autoimmune uveitis (EAU). The aqueous humor (AH) was collected 2 weeks after immunization. Fifty-four human AH specimens, among which 21 eyes had a history of chronic uveitis, were collected during their cataract surgery. The profile of OxPLs in the AH specimens were analyzed by liquid-chromatography tandem mass spectrometry (LC-MS/MS). In addition, the involvement of macrophages in the viability of cells treated by OxPLs was investigated through a WST-1 assay using ARPE-19 cells and C57BL/6 mouse alveolar macrophages (AMs). The influence of macrophages in the trend of OxPLs was traced by thin layer chromatography (TLC) using AMs. Results: Six species of OxPLs were detected in the AHs of rats and humans. The content of each OxPL was higher in the uveitis group. Four kinds of OxPLs found in AHs showed cytotoxicity to ARPE-19 cells in a dose-dependent manner. The cytotoxicity was reduced by pretreatment of OxPLs with AMs. When the OxPLs were applied on AMs, a marked reduction of OxPLs in the medium was observed. Conclusions: The OxPLs formed by intraocular inflammation could induce cytotoxicity. The present findings suggest that the phagocytic macrophages emerging in the inflammation site eliminate OxPLs, and prevent intraocular tissue damage following uveitis.


Assuntos
Humor Aquoso/metabolismo , Macrófagos/metabolismo , Fosfolipídeos/metabolismo , Uveíte/metabolismo , Idoso , Idoso de 80 Anos ou mais , Animais , Cromatografia Líquida , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxirredução , Ratos , Ratos Endogâmicos Lew
15.
Acta Cir Bras ; 35(5): e202000503, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32578671

RESUMO

PURPOSE: To investigate the effect of hyperbaric oxygen therapy on colonic anastomosis healing with and without ischemia in rats. METHODS: Forty female rats underwent segmental resection of 1 cm of the left colon followed by end-to-end anastomosis. They were randomly assigned to four groups (n=10 each), a sham group; two groups were submitted to Hyperbaric Oxygen therapy (HBOT) with and without induced ischemia and the induced ischemia group without HBOT. The HBOT protocol evaluated was 100% O2 at 2.4 Atmosphere absolute pressure (ATA) for 60 minutes, two sessions before as a preconditioning protocol and three sessions after the operation. Clinical course and mortality were monitored during all experiment and on the day of euthanasia on the fourth day after laparotomy. Macroscopic appearance of the abdominal cavity were assessed and samples for breaking strength of the anastomosis and histopathological parameters were collected. RESULTS: There was no statistically significant difference in mortality or anastomosis leak between the four experimental groups. Anastomosis breaking strength was similar across groups. CONCLUSION: The HBOT protocol tested herein at 2.4 ATA did not affect histopathological and biomechanical parameters of colonic anastomotic healing, neither the clinical outcomes death and anastomosis leak on the fourth day after laparotomy.


Assuntos
Colo/irrigação sanguínea , Colo/cirurgia , Oxigenação Hiperbárica/métodos , Isquemia/patologia , Precondicionamento Isquêmico/métodos , Cicatrização , Anastomose Cirúrgica , Animais , Colo/patologia , Feminino , Isquemia/prevenção & controle , Período Pós-Operatório , Ratos Endogâmicos Lew , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
16.
Am J Physiol Renal Physiol ; 319(1): F76-F83, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32475131

RESUMO

Acutely increased renal venous pressure (RVP) impairs renal function, but the long-term impact is unknown. We investigated whether chronic RVP elevation impairs baseline renal function and prevents exacerbation of renal dysfunction and cardiovascular instability upon further RVP increase. RVP elevation (20-25 mmHg) or sham operation (sham) was performed in rats. After 1 wk (n = 17) or 3 wk (n = 22), blood pressure, RVP, renal blood flow (RBF), renal vascular conductance (RVC), and glomerular filtration rate (GFR) were measured at baseline and during superimposed RVP increase. Chronic RVP elevation induced extensive renal venous collateral formation. RVP fell to 6 ± 1 mmHg at 1 wk and 3 ± 1 mmHg at 3 wk. Baseline blood pressure and heart rate were unaltered compared with sham. RBF, RVC, and GFR were reduced at 1 wk but normalized by 3 wk. Upon further RVP increase, the drop in mean arterial pressure was attenuated at 3 wk compared with 1 wk (P < 0.05), whereas heart rate fell comparably across all groups; the mean arterial pressure-heart rate relationship was disrupted at 1 and 3 wk. RBF fell to a similar degree as sham at 1 wk (-2.3 ± 0.7 vs. -3.9 ± 1.2 mL/min, P = 0.066); however, at 3 wk, this was attenuated compared with sham (-1.5 ± 0.5 vs. -4.2 ± 0.7 mL/min, P < 0.05). The drop in RVC and GFR was attenuated at 1 and 3 wk (P < 0.05). Thus, chronic RVP elevation induced by partial renal vein ligation elicits extensive renal venous collateral formation, and although baseline renal function is impaired, chronic RVP elevation in this manner induces protective adaptations in kidneys of healthy rats, which attenuates the hemodynamic response to further RVP increase.


Assuntos
Taxa de Filtração Glomerular/fisiologia , Hipertensão Renal/fisiopatologia , Rim/fisiopatologia , Circulação Renal/fisiologia , Veias Renais/fisiopatologia , Animais , Pressão Sanguínea/fisiologia , Frequência Cardíaca/fisiologia , Hemodinâmica/fisiologia , Rim/irrigação sanguínea , Masculino , Ratos , Ratos Endogâmicos Lew
17.
BMC Cardiovasc Disord ; 20(1): 294, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32539686

RESUMO

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has gained widespread acceptance for the treatment of critically ill patients suffering from cardiac and/or respiratory failure. Various animal models have been developed to investigate the adverse effects induced by ECMO. Different membrane oxygenators have been used with varying priming volumes and membrane surfaces (Micro-1, small animal membrane oxygenator (SAMO)). METHODS: Sixteen male Lewis rats (350-400 g) were randomly assigned to receive ECMO with Micro-1 or SAMO (n = 8, respectively). Venoarterial ECMO was established after cannulation of the femoral artery and the jugular vein. The cardiac output was measured using a left-ventricular conductance catheter. The oxygen fraction of the ECMO was set to 1.0, 0.75, 0.5 and 0.21 after a stabilisation period of 15 min. Further, arterial blood gas analyses were performed at baseline, and during the first hour every 15 min after commencing the ECMO, and subsequently every 30 min. Dilutional anaemia was calculated using haemoglobin concentration at baseline, and 15 min after the start of ECMO therapy. Moreover, inflammation was determined by measuring tumour necrosis factor alpha, interleukin-6 and -10 at baseline and every 30 min. RESULTS: Animals of the Micro-1 group showed a significantly lower dilutional anaemia (ΔHaemoglobin t0 - t0.25: SAMO 6.3 [5.6-7.5] g/dl vs. Micro-1 5.6 [4.6-5.8] g/dl; p = 0.028). Further, significantly higher oxygen partial pressure was measured in the SAMO group, at an oxygen fraction of 0.75, 0.5 and 0.21 (380 [356-388] vs. 314 [263-352] mmHg, p = 0.002; 267 [249-273] mmHg vs. 197 [140-222] mmHg, p = 0.002; 87 [82-106] mmHg vs. 76 [60-79] mmHg, p = 0.021, respectively). However, no differences were found regarding the oxygen fraction of 1.0, in terms of carbon-dioxide partial pressure and cardiac output. Moreover, in the Micro-1 group tumour necrosis factor alpha was increased after 60 min and interleukin-6 after 120 min. CONCLUSION: While the dilutional anaemia was increased after commencing the ECMO, the oxygenation was augmented in the SAMO group. The inflammatory response was elevated in the Micro-1 group.


Assuntos
Anemia/etiologia , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/instrumentação , Hemoglobinas/metabolismo , Mediadores da Inflamação/sangue , Inflamação/etiologia , Oxigênio/sangue , Oxigenadores de Membrana , Anemia/sangue , Animais , Biomarcadores/sangue , Descarboxilação , Desenho de Equipamento , Inflamação/sangue , Masculino , Ratos Endogâmicos Lew , Fatores de Tempo
18.
Biochem Pharmacol ; 180: 114108, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32569628

RESUMO

Noninfectious (autoimmune and immune-mediated) uveitis is an ocular inflammatory disease which can lead to blindness in severe cases. Due to the potential side effects of first-line drugs for clinical uveitis, novel drugs and targets against uveitis are still urgently needed. In the present study, using rat experimental autoimmune uveitis (EAU) model, we first found that minocycline treatment can substantially inhibit the development of EAU and improve the retinal function by suppressing the retinal microglial activation, and block the infiltration of inflammatory cells, including Th17, into the retina by decreasing the major histocompatibility complex class II (MHC II) expression in resident and infiltrating cells. Moreover, we demonstrated that minocycline treatment can remodel the gut microenvironment of EAU rats by restoring the relative abundance of Ruminococcus bromii, Streptococcus hyointestinalis, and Desulfovibrio sp. ABHU2SB and promoting a functional shift in the gut via reversing the levels of L-proline, allicin, aceturic acid, xanthine, and leukotriene B4, and especially increasing the production of propionic acid, histamine, and pantothenic acid. At last, we revealed that minocycline treatment can significantly attenuate the progression of EAU after inflammation onset, which may be explained by the role of minocycline in the remodeling of the gut microenvironment since selective elimination of retinal microglia on the later stages of EAU was shown to have little effect. These data clearly demonstrated that inhibition of microglial activation and remodeling of the gut microenvironment can suppress the development and progression of experimental autoimmune uveitis. Considering the excellent safety profile of minocycline in multiple clinical experiments, we suggest that minocycline may have therapeutic implications for clinical uveitis.


Assuntos
Doenças Autoimunes/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Microglia/efeitos dos fármacos , Minociclina/uso terapêutico , Retina/efeitos dos fármacos , Uveíte/tratamento farmacológico , Animais , Doenças Autoimunes/imunologia , Microambiente Celular/efeitos dos fármacos , Microambiente Celular/imunologia , Modelos Animais de Doenças , Microbioma Gastrointestinal/imunologia , Antígenos de Histocompatibilidade Classe II/biossíntese , Masculino , Microglia/imunologia , Ratos , Ratos Endogâmicos Lew , Retina/imunologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Células Th17/patologia , Uveíte/imunologia , Uveíte/patologia
19.
PLoS One ; 15(5): e0233497, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32442182

RESUMO

Mixed hematopoietic chimerism enables donor-specific tolerance for solid organ grafts. This study evaluated the influence of different serological major histocompatibility complex disparities on chimerism development, graft-versus-host disease incidence and subsequently on solid organ tolerance in a rat model. For bone marrow transplantation conditioning total body irradiation was titrated using 10, 8 or 6 Gray. Bone marrow transplantation was performed across following major histocompatibility complex mismatched barriers: complete disparity, MHC class II, MHC class I or non-MHC mismatch. Recipients were clinically monitored for graft-versus-host disease and analyzed for chimerism using flow cytometry. After a reconstitution of 100 days, composition of peripheral leukocytes was determined. Mixed chimeras were challenged with heart grafts from allogeneic donor strains to define the impact of donor MHC class disparities on solid organ tolerance on the basis of stable chimerism. After myeloablation with 10 Gray of total body irradiation, chimerism after bone marrow transplantation was induced independent of MHC disparity. MHC class II disparity increased the incidence of graft-versus-host disease and reduced induction of stable chimerism upon myelosuppressive total body irradiation with 8 and 6 Gray, respectively. Stable mixed chimeras showed tolerance towards heart grafts from donors with MHC matched to either bone marrow donors or recipients. Isolated matching of MHC class II with bone marrow donors likewise led to stable tolerance as opposed to matching of MHC class I. In summary, MHC class II disparity was critically associated with the onset of graft-versus host disease and was identified as obstacle for successful development of chimerism after bone marrow transplantation and subsequent donor-specific solid organ tolerance.


Assuntos
Transplante de Medula Óssea , Antígenos de Histocompatibilidade Classe II/imunologia , Quimeras de Transplante/imunologia , Tolerância ao Transplante/imunologia , Aloenxertos , Animais , Doença Enxerto-Hospedeiro/imunologia , Transplante de Coração , Humanos , Masculino , Modelos Animais , Modelos Imunológicos , Transplante de Órgãos , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Doadores de Tecidos , Condicionamento Pré-Transplante , Irradiação Corporal Total
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