RESUMEN
Maslinic acid is a pentacyclic triterpene with a plethora of biological activities, including anti-inflammatory, antioxidant, antimicrobial, cardioprotective, and antitumor effects. New derivatives with improved properties and broad-spectrum activity can be obtained following structural changes of the compound. The present study was aimed to characterize a benzylamide derivative of maslinic acid-benzyl (2α, 3ß) 2,3-diacetoxy-olean-12-en-28-amide (EM2)-with respect to the anti-angiogenic and anti-inflammatory effects in two in vivo experimental models. Consequently, the compound showed good tolerability and lack of irritation in the chorioallantoic membrane assay with no impairment of the normal angiogenic process during the tested stages of development. In the acute ear inflammation murine model, application of EM2 induced a mild anti-inflammatory effect that was potentiated by the association with zinc chloride (ZnCl2). A decrease in dermal thickness of mice ears was observed when EM2 and ZnCl2 were applied separately or in combination. Moreover, hyalinization of the dermis appeared only when EM2 was associated with ZnCl2, strongly suggesting the role of their combination in wound healing.
Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Antiinflamatorios/uso terapéutico , Otitis/tratamiento farmacológico , Triterpenos/uso terapéutico , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/efectos adversos , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/efectos adversos , Embrión de Pollo , Cloruros/administración & dosificación , Cloruros/uso terapéutico , Membrana Corioalantoides/efectos de los fármacos , Quimioterapia Combinada , Femenino , Ratones , Triterpenos/administración & dosificación , Triterpenos/efectos adversos , Compuestos de Zinc/administración & dosificación , Compuestos de Zinc/uso terapéuticoRESUMEN
BACKGROUND: Depression is a serious and complex mental disease that has attracted worldwide attention because of its high incidence rate, high disability rate and high mortality. Excitotoxicity is one of the most important mechanisms involved in the pathophysiological process of depression. In our previous studies, n-butanol extract from maize roots was found to have good neuroprotective effects due to its antioxidative activity. However, the antidepressive effective constituents, efficacy in vivo and mechanism of action of maize root extracts have not been determined. PURPOSE: This study aimed to determine the main active neuroprotective compound in maize root extract and investigate its antidepressant effects and possible underlying mechanism in vitro and in vivo. METHODS: Sixteen extracts were isolated and purified from maize roots. The active components of the most active extracts of maize roots (hereafter referred to as EM 2) were identified using UF-HPLC-QTOF/MS. In vitro cell models of NMDA-induced excitotoxicity in SH-SY5Y cells were used to analyze the anti-excitatory activity of the extracts. The MTT assay and Annexin V-FITC/PI Apoptosis Detection were used to evaluate cell viability. Several network pharmacological strategies have been employed to investigate the potential mechanism of action of EM 2. The effects of EM 2 on depressive-like behaviors were evaluated in CUMS mice. Changes in the levels of related proteins were detected via western blotting. RESULTS: Among the 16 extracts extracted by n-butanol, EM 2 was determined to be the most active extract against NMDA-induced excitotoxicity by n-butanol extraction. Meanwhile, seventeen compounds were further identified as the main active components of EM 2. Mechanistically, EM 2 inhibited NMDA-induced excitatory injury in SH-SY5Y cells and alleviated the depressive-like behaviors of CUMS mice by suppressing NR2B and subsequently mediating the downstream CREB/TRKB/BDNF, PI3K/Akt and MAPK pathways, as well as the Nrf2/HO-1 antioxidant signaling pathway. CONCLUSION: The study indicated that EM 2 could potentially be developed as a potential therapeutic candidate to cure depression in NMDA-induced excitatory damage.
Asunto(s)
Antidepresivos , Apoptosis , Depresión , Fármacos Neuroprotectores , Extractos Vegetales , Raíces de Plantas , Zea mays , Animales , Antidepresivos/farmacología , Zea mays/química , Extractos Vegetales/farmacología , Extractos Vegetales/química , Raíces de Plantas/química , Humanos , Ratones , Depresión/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Línea Celular Tumoral , Apoptosis/efectos de los fármacos , Masculino , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Supervivencia Celular/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
We report the synthesis and pharmacological characterization of a novel glycosylated analog of a potent and selective endogenous µ-opioid receptor (MOP) agonist, endomorphin-2 (Tyr-Pro-Phe-Phe-NH2, EM-2), obtained by the introduction in position 3 of the tyrosine residue possessing the glucose moiety attached to the phenolic function via a ß-glycosidic bond. The improved blood-brain barrier permeability and enhanced antinociceptive effect of the novel glycosylated analog suggest that it may be a promising template for design of potent analgesics. Furthermore, the described methodology may be useful for increasing the bioavailability and delivery of opioid peptides to the CNS.
Asunto(s)
Analgésicos/química , Oligopéptidos/química , Oligopéptidos/farmacología , Receptores Opioides mu/agonistas , Secuencia de Aminoácidos , Analgésicos/farmacología , Animales , Barrera Hematoencefálica/metabolismo , Glicosilación , Inyecciones Intravenosas , Ratones , Dimensión del Dolor/efectos de los fármacos , Permeabilidad/efectos de los fármacos , Receptores Opioides mu/metabolismoRESUMEN
BACKGROUND: EM-2, a natural sesquiterpene lactone isolated from Elephantopus mollis H.B.K., showed a good anti-breast cancer effect when combined with epirubicin (EPI). However, its synergistic sensitization mechanism remains unclear. PURPOSE: This study aimed to determine the therapeutic effect and possible synergistic mechanism of EM-2 with EPI in vivo and in vitro and to provide an experimental basis for the treatment of human breast cancer. METHODS: Cell proliferation was measured with MTT and colony formation assays. Apoptosis and reactive oxygen species (ROS) levels were examined through flow cytometry, and the expression levels of proteins related to apoptosis, autophagy, endoplasmic reticulum stress, and DNA damage were detected through Western blot analysis. Moreover, the caspase inhibitor Z-VAD-FMK, autophagy inhibitors bafilomycin A1 and chloroquine, ER stress inhibitor 4-phenylbutyric acid, and ROS scavenger N-acetyl cysteine were applied to verify signaling pathways. Breast cancer cell lines were used to evaluate the antitumor functions of EM-2 and EPI in vitro and in vivo. RESULTS: We demonstrated that in MDA-MB-231 and SKBR3 cells, the IC50 of EPI combined with EM-2 (IC20) was 37.909 and 33.889 times lower than that of EPI alone, respectively. Further study verified that in EPI-resistant lines (MDA-MB-231/EPI), the IC50 of EPI combined with EM-2 (IC20) was 26.305 times lower than that of EPI alone. Mechanistically, EM-2 could reverse the protective effect of EPI against autophagy in SKBR3 and MDA-MB-231 cells. EM-2 and EPI could trigger ER stress. When EM-2 and EPI were used in combination, ER stress was continuously activated, and ER stress-mediated apoptosis was induced. Meanwhile, EM-2 combined with EPI promoted DNA damage then induced apoptosis. In vivo, the volume of breast cancer xenografts in the combination group was smaller than that in the control, EM-2, and EPI groups. Immunohistochemical experiments demonstrated that the combination of EM-2 and EPI could block autophagy and promote ER stress in vivo. CONCLUSION: EM-2 enhances the sensitivity of MDA-MB-231, SKBR3, and EPI-resistant cells to EPI.
Asunto(s)
Neoplasias de la Mama , Sesquiterpenos , Humanos , Femenino , Epirrubicina , Especies Reactivas de Oxígeno/metabolismo , Línea Celular Tumoral , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Autofagia , Apoptosis , Sesquiterpenos/farmacología , Proliferación CelularRESUMEN
Alveolar (AE) and cystic echinococcosis (CE) are severe parasitic zoonoses caused by the larval stages of Echinococcus multilocularis and E. granulosus sensu lato, respectively. A panel of 7 monoclonal antibodies (mAbs) was selected against major diagnostic epitopes of both species. The binding capacity of the mAbs to Echinococcus spp. excretory/secretory products (ESP) was analyzed by sandwich-ELISA, where mAb Em2G11 and mAb EmG3 detected in vitro extravesicular ESP of both E. multilocularis and E. granulosus s.s. These findings were subsequently confirmed by the detection of circulating ESP in a subset of serum samples from infected hosts including humans. Extracellular vesicles (EVs) were purified, and the binding to mAbs was analyzed by sandwich-ELISA. Transmission electron microscopy (TEM) was used to confirm the binding of mAb EmG3 to EVs from intravesicular fluid of Echinococcus spp. vesicles. The specificity of the mAbs in ELISA corresponded to the immunohistochemical staining (IHC-S) patterns performed on human AE and CE liver sections. Antigenic small particles designated as ''spems'' for E. multilocularis and ''spegs'' for E. granulosus s.l. were stained by the mAb EmG3IgM, mAb EmG3IgG1, mAb AgB, and mAb 2B2, while mAb Em2G11 reacted with spems and mAb Eg2 with spegs only. The laminated layer (LL) of both species was strongly visualized by using mAb EmG3IgM, mAb EmG3IgG1, mAb AgB, and mAb 2B2. The LL was specifically stained by mAb Em2G11 in E. multilocularis and by mAb Eg2 in E. granulosus s.l. In the germinal layer (GL), including the protoscoleces, a wide staining pattern with all structures of both species was observed with mAb EmG3IgG1, mAb EmG3IgM, mAb AgB, mAb 2B2, and mAb Em18. In the GL and protoscoleces, the mAb Eg2 displayed a strong E. granulosus s.l. specific binding, while mAb Em2G11 exhibited a weak granular E. multilocularis specific reaction. The most notable staining pattern in IHC-S was found with mAb Em18, which solely bound to the GL and protoscoleces of Echinococcus species and potentially to primary cells. To conclude, mAbs represent valuable tools for the visualization of major antigens in the most important Echinococcus species, as well as providing insights into parasite-host interactions and pathogenesis.
Asunto(s)
Equinococosis , Echinococcus multilocularis , Vesículas Extracelulares , Animales , Humanos , Anticuerpos Monoclonales , Antígenos Helmínticos , Equinococosis/diagnóstico , Inmunoglobulina MRESUMEN
Background: Alveolar echinococcosis (AE) is a severe larval tapeworm infection with a variable clinical course of the disease. Reliable imaging techniques and biomarkers are needed to predict the course of the disease. Methods: 179 AE patients that received PET/CT scans between 2008 and 2012 were retrospectively included. From stored blood samples taken on the day of the scan, levels of IgE, parasite-specific serology, amyloid A, C-reactive protein, soluble interleukin 2 receptor, cytokeratin fragments, eosinophilic cell count, and eosinophil cationic protein were measured. Additionally, the current clinical outcome (cured, stable, or progressive disease) after a median duration of 8 years after baseline examination was assessed. Ultimately, an ordinal logistic regression was conducted to evaluate which imaging parameters and biomarkers independently influence the clinical outcome. Results: In general, patients in need of medical treatment or with progressive disease, advanced PNM stages, and positive PET/CT scans exhibited higher levels of the respective biomarkers. However, only the parasite-specific serological markers and total IgE levels differed significantly between clinical groups, WHO PNM stages, and the results of the PET/CT scan. In the multivariate analysis, PET/CT results were a strong predictor of the clinical outcome (OR 8.908, 95%CI 3.019-26.285; p < 0.001), and age at baseline was a moderate predictor (OR 1.031, 95%CI 1.003-1.060; p = 0.029). Conclusions: The PET/CT scan is, preferably in combination with parasite-specific serology and IgE levels, a valuable tool in the clinical management of AE and is able to predict the course of the disease.
RESUMEN
Endomorphin-2 (EM2)-immunoreactive (ir) ï¬bers and terminals in the superï¬cial laminae (lamina I and II) of the spinal dorsal horn (SDH) primarily come from neurons in the ipsilateral dorsal root ganglion (DRG), which are important for nociceptive information transmission and modulation. However, the morphological features of EM2-ir neurons and fibers in the DRG and terminals in the SDH under ultrastructural levels have not been completely revealed. The present study observed the distributions of EM2-ir neurons, fibers and terminals in the DRG and SDH and detected their ultrastructural features using immunoelectron microscopy. EM2-ir neurons in the DRG are primarily small or medium in size and account for 17.2% of all neurons in the DRG. EM2-ir large dense-core granule vesicles (LDCVs) are dispersed in the cytoplasm and fibers. Most of the central processes of DRG neurons were thin myelinated and unmyelinated fibers and contained a few EM2-ir LDCVs. An intensive string of EM2-ir fibers with beads and terminals were observed in the superficial laminae of the SDH, other than EM2-ir neurons. EM2-ir products were also detected sparsely in the fibers and terminals. The average diameter of terminals was 94.41 ± 18.13 nm. EM2-ir terminals formed different types of synapses, most of which were asymmetrical (91%). EM2-ir LDCVs colocalized primarily with spherical small clear vesicles in asymmetrical synapses and flat vesicles in symmetrical synapses. The average length of postsynaptic dense zones (PSDs) measured in the asymmetrical synapses was 317.00 ± 31.67 nm. These results indicate that EM2-containing structures are distributed in the cytoplasm of DRG neurons, the central processes and terminals in the SDH and provide morphological evidence for the antinociceptive effects of EM2 in the SDH.
Asunto(s)
Ganglios Espinales , Asta Dorsal de la Médula Espinal , Ratas , Animales , Oligopéptidos , Microscopía Inmunoelectrónica , Médula Espinal/fisiologíaRESUMEN
PK20M (Dmt-D-Lys-Phe-Phe-OH) is a novel modified endomorphin-2 (EM-2) peptide producing strong dose- and time-dependent antinociceptive activity. Yet its prototype, endogenous EM-2, has been reported to trigger respiratory and vascular effects such as apnea and hypotension. The purpose of this study was to investigate the potency of the PK20M to evoke respiratory and cardiovascular responses in comparison to endogenous endomorphins. The engagement of the vagal pathway and µ opioid receptors in mediation of these responses was investigated. The effects of intravenous injections of PK20M, EM-1, and EM-2 were studied in anaesthetized, spontaneously breathing rats. The main dose-dependent effect of all endomorphins in the intact rats was immediate apnea, blood pressure and heart rate decrease. PK20M produced apnea in at least half of the intact animals in a much smaller dose than EM-1 and EM-2. The effects of all compounds were abrogated by pre-treatment with MNLX, a peripherally acting µ receptor antagonist. Cervical vagotomy eliminated arrest of breathing in the case of each tested compound. Hypotension was reduced by vagi section only after EM-1 and EM-2 administration. Our results demonstrated that apnea and bradycardia caused by systemic injection of all endomorphins were mediated via activation of µ vagal opioid receptors. The hypotension depended on intact vagi nerves only in the case of EM-1 and EM-2, whereas PK20M decreased blood pressure via other mechanisms outside vagal innervation. Modified opioid agonist is more potent in evoking extended hypotension; at the same time, it produces an arrest of breathing less frequently than its prototype EM-2.
Asunto(s)
Analgésicos/farmacología , Apnea/inducido químicamente , Hipotensión/inducido químicamente , Oligopéptidos/farmacología , Péptidos Opioides/farmacología , Enfermedades del Nervio Vago/inducido químicamente , Analgésicos Opioides/farmacología , Animales , Bradicardia/inducido químicamente , Bradicardia/fisiopatología , Relación Dosis-Respuesta a Droga , Inyecciones Intravenosas , Masculino , Ratas , Ratas Wistar , Mecánica Respiratoria/efectos de los fármacos , VagotomíaRESUMEN
Endometrial cancer, a type of primary epithelial malignant tumor in the endometrium, is one of the three most common malignant tumors of the female reproductive system. While the incidence of endometrial cancer has been recently rising, its etiology remains unclear. In this study we found that EM2D9, an independently developed monoclonal antibody, specifically recognized endometrial cancer cells; we further determined that EM2D9 target protein was α5ß1. In vitro and in vivo experiments showed that EM2D9 inhibited the migration of endometrial cancer cells. Real-time quantitative PCR results showed that the expression of CD151 mRNA in endometrial carcinoma cells significantly decreased after EM2D9 treatment. We also found that EM2D9 affected the FAK signaling pathway. Collectively, these results shed light on a new mechanism for the development of endometrial carcinoma.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Antineoplásicos Inmunológicos/farmacología , Movimiento Celular/efectos de los fármacos , Neoplasias Endometriales/tratamiento farmacológico , Integrina alfa5beta1/antagonistas & inhibidores , Integrina beta1 , Integrinas/antagonistas & inhibidores , Animales , Línea Celular Tumoral , Neoplasias Endometriales/genética , Neoplasias Endometriales/metabolismo , Neoplasias Endometriales/patología , Femenino , Quinasa 1 de Adhesión Focal/metabolismo , Humanos , Integrina alfa5beta1/metabolismo , Integrina beta1/metabolismo , Integrinas/metabolismo , Ratones Endogámicos NOD , Ratones SCID , Transducción de Señal , Tetraspanina 24/genética , Tetraspanina 24/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND AND OBJECTIVES: Alveolar and cystic echinococcosis (AE and CE) are caused by the larval stages of Echinococcus multilocularis and Echinococcus granulosus, respectively. This study aimed to determine the prevalence of human AE and CE diseases among the tribes, livestock breeders, and farmers in Moghan plain, northwest of Iran. MATERIALS AND METHODS: Screening of hydatid cystic fluid antigen (HCF-Ag) was done by enzyme-linked immunosorbent (ELISA) kit. Briefly, HCF-Ag was collected, and the prevalence of the disease was evaluated using specific antigens for AE and CE (Ag-5, Ag-B, and Em2+) and questionnaires. A total of 2453 serum samples were randomly collected from normal populations of five different areas of Moghan plain. The serology was evaluated using ELISA kit and specific antigens for AE and CE. RESULTS: Of the 2453 serum samples, 36 were positive for AE (1.46%). The infection rate was higher in males than females (1.94% vs. 0.94%). The age group of 4-19 years had the lowest and 40-59 years had the highest infection rate (0.2% vs. 2.5%). Among CE-positive serum samples, 178 samples were positive to Ag-5 (7.3%) and 167 samples were positive to Ag-B (6.8%). CONCLUSION: Our findings showed that the highest infection rates were in the Borran and Eivazlou regions, and the lowest level of infection was for Parsabad area of Moghan plain. In areas with higher contamination, the risk factors associated with CE and AE were the water quality, the method of washing vegetables, and occupational and hydatid disease knowledge of the inhabitants.
RESUMEN
ABSTRACT: Analysis of locomotion is often used as a measure for impairment and recovery following experimental peripheral nerve injury. Compared to rodents, sheep offer several advantages for studying peripheral nerve regeneration. In the present study, we compared for the first time, two-dimensional (2D) and three-dimensional (3D) hindlimb kinematics during obstacle avoidance in the ovine model. This study obtained kinematic data to serve as a template for an objective assessment of the ankle joint motion in future studies of common peroneal nerve (CP) injury and repair in the ovine model. The strategy used by the sheep to bring the hindlimb over a moderately high obstacle, set to 10% of its hindlimb length, was pronounced knee, ankle and metatarsophalangeal flexion when approaching and clearing the obstacle. Despite the overall time course kinematic patterns about the hip, knee, ankle, and metatarsophalangeal were identical, we found significant differences between values of the 2D and 3D joint angular motion. Our results showed that the most apparent changes that occurred during the gait cycle were for the ankle (2D-measured STANCEmax: 157±2.4 degrees vs. 3D-measured STANCEmax: 151±1.2 degrees; P<.05) and metatarsophalangeal joints (2D-measured STANCEmin: 151±2.2 degrees vs. 3D-measured STANCEmin: 162 ± 2.2 degrees; P<.01 and 2D-measured TO: 163±4.9 degrees vs. 3D-measured TO: 177±1.4 degrees; P<.05), whereas the hip and knee joints were much less affected. Data and techniques described here are useful for an objective assessment of altered gait after CP injury and repairin an ovine model.
RESUMO: A análise da locomoção é frequentemente usada como uma medida para avaliar a disfunção e sua recuperação após lesão nervosa periférica experimental. Quando comparadas com os roedores, as ovelhas oferecem várias características atrativas como modelo experimental para o estudo da regeneração nervosa periférica. Não existem estudos acerca dos resultados da locomoção após lesão e reparação do nervo periférico no modelo ovino. No presente estudo, realizámos e comparámos a cinemática bidimensional (2D) e, pela primeira vez, tridimensional (3D) do membro pélvico durante a ultrapassagem de obstáculos no modelo ovino. Este estudo teve como objetivo obter dados cinemáticos para servir de modelo para uma avaliação objetiva do movimento articular do tornozelo em estudos futuros de lesão e reparação do nervo fibular comum (FC) no modelo ovino. A estratégia usada pelas ovelhas para elevar o membro pélvico sobre um obstáculo com uma altura moderada, fixado em 10% do seu comprimento, caracteriza-se por uma flexão pronunciada do joelho, tornozelo e metatarso-falangeana ao se aproximar e ultrapassar o obstáculo. Apesar dos padrões cinemáticos do quadril, joelho, tornozelo e metatarso-falangeano terem sido idênticos, foram encontradas diferenças significativas entre os valores do movimento angular das articulações em 2D e 3D. Os nossos resultados mostram que as mudanças mais aparentes que ocorreram durante o ciclo da marcha foram nas articulações do tornozelo (em 2DSTANCEmax: 157±2.4 graus vs. em 3D STANCEmax: 151±1.2 graus; P<.05) e metatarso-falangeana (em 2D STANCEmin: 151±2.2 graus vs. em 3D STANCEmin: 162 ± 2.2 graus; P<.01 e em 2D TO: 163±4.9 graus vs. em 3D TO: 177±1.4 graus; P<.05), enquanto as articulações do quadril e do joelho foram muito menos afetadas. É provável que os dados e técnicas descritas aqui sejam úteis para uma avaliação objetiva das alterações na marcha após lesão e reparação do PC no modelo ovino.
RESUMEN
A novel species-specific anti-beaver-IgG-alkaline-phosphatase conjugate was synthesized for the development of a new serological test for echinococcosis in beavers. Two different ELISAs conventionally used for human Echinococcus multilocularis serology (Em18-ELISA and Em2-ELISA) yielded diagnostic sensitivities of 0% and 46%, respectively. In contrast, the subsequently developed immunoblotting assay gave an 85% diagnostic sensitivity (11 out of 13 beavers with alveolar echinococcosis were immunoblotting-positive, i.e. showed reactivity with a specific 21 Mr band), and maximal specificity. In conclusion, this immunoblotting assay should be the method of choice for use in serological studies on E. multilocularis in Eurasian beavers, and the test proved suitable to investigate both animals alive and post-mortem.
Asunto(s)
Anticuerpos Antihelmínticos/sangre , Equinococosis Hepática/veterinaria , Immunoblotting/veterinaria , Roedores/parasitología , Animales , Equinococosis , Equinococosis Hepática/diagnóstico , Echinococcus/inmunología , Sensibilidad y EspecificidadRESUMEN
Endomorphin-1 (EM-1) and endomorphin-2 (EM-2) are opioid peptides which are selective partial agonists of µ-opioid receptor. We studied the effects of EM-2 injected into the arcuate nucleus (ARC) of the hypothalamus on feeding behavior and gene expression of orexigenic [agouti-related peptide (AgRP), neuropeptide Y (NPY) and orexin-A] and anorexigenic [cocaine and amphetamine-regulated transcript (CART), corticotrophin releasing hormone (CRH) and proopiomelanocortin (POMC)] peptides in male Wistar rats fed a standard laboratory diet. Furthermore, we evaluated the effects of EM-2 on dopamine (DA), norepinephrine (NE) and serotonin (5-hydroxytryptamine, 5-HT) steady state concentrations, in the hypothalamus. 64 rats (16 for each group of treatment) were injected into the ARC, at 9.00 am, with either vehicle or EM-2 (0.50-0.75 µmol/kg) or EM-2 (0.50 µmol/kg) plus ß-funaltrexamine (0.20 µmol/kg). Food intake was recorded through 24h following injection, and hypothalamic DA, NE, 5-HT levels and neuropeptide gene expression were evaluated 24h after EM-2 administration. Compared to vehicle, EM-2 significantly increased food intake, throughout 24h post-injection. Furthermore, EM-2 treatment led to a significant increase of DA and NE concentrations and a decrease of CRH mRNA levels. On the other hand, ß-funaltrexamine administration reverted both feeding stimulatory and neuromodulatory effects induced by EM-2. We can conclude that the orexigenic effect of µ-opioid receptor activation by EM-2 could be related to both inhibition of CRH and stimulation of dopamine and norepinephrine levels, in the hypothalamus.