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INTRODUCTION: One of the main causes of a neurogenic bladder is spinal cord injury (SCI),(SCI), which induces little or no bladder reflex activity. Because of this alteration, there is an increased risk of developing urinary tract infections and kidney damage. Gonadotropin-releasing hormone (GnRH) treatment has been shown to improve micturition in a rat model of SCI. AIM: The present study was aimed at determining whether GnRH administration is capable to reduce bladder and kidney damage in rats with SCI. METHODS: Ovariectomized female Wistar rats were divided into three groups: sham, SCI with saline solution (SCI), and SCI treated with GnRH (SCI+GnRH) for 6 weeks. SCI was induced by compression at the T10 spinal level. At the end of the experiment, bladders and kidneys were processed for morphological and immunofluorescence analysis. For morphometric analysis, the thickness of the urothelium and the muscular layer of the bladder was measured, as well as the intensity of staining related to collagen in the kidney. RESULTS: At the end of the experiment, all animals in the sham group showed normal urination (100%), in contrast, the percentage of untreated injured rats (SCI) that did not require manual stimulation for micturition was 19%, while the treated group (SCI+GnRH) was 68%. A significative increase in bladder weight, urothelial and muscle thickness, and collagen-related coloration in the kidney was observed in SCI when compared to sham rats. CONCLUSION: GnRH administration decreased damage to the urinary bladder and kidneys after SCI in rats. These results suggest that this hormone could be a potential preventive treatment for SCI patients at risk of neurogenic bladder and kidney damage. TRIAL REGISTRATION: Not applicable.
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BACKGROUND: Mild hypoxic-ischemic encephalopathy (HIE) is a condition that predisposes to negative outcomes such as neuroanatomical injury, mood disorders, and motor or cognitive disabilities. The neuroinflammation plays an important role in the neurological damage; therefore, reducing it could provide neuroprotection. The leuprolide acetate (LA) has shown to have neuroregenerative and immunomodulator properties in other nervous system injuries. OBJECTIVE: The aim of this study was to evaluate the immunomodulatory effect of LA in the acute phase of mild HIE and its effects in motor activity and behavior in a subacute phase. METHOD: Forty-five Wistar rats on postnatal day 7 were divided into Sham, HIE treated with saline solution (HIE-SS), and HIE-LA. The HIE was performed cutting of the right carotid artery followed by 60 min of hypoxia. The expression of the inflammatory cytokines interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and the chemokine CXCL-1 were evaluated 72 h after HIE by RT-qPCR and the motor activity and behavior were evaluated by open field test at postnatal day 33. RESULTS: HIE-SS animals showed increased expression of IL-1ß, TNF-α, IFN-γ, and CXCL-1 genes in injured tissue. However, the HIE-LA group exhibited similar expression levels of IL-1ß and TNF-α to the Sham group, while IFN-γ and CXCL-1 mRNA expression were attenuated with LA treatment. LA treatment also prevented anxiety-like behavior in the open field test. CONCLUSION: Treatment with LA partially reverses HIE-induced neuroinflammation and prevents anxiety-like behavior in neonatal rats.
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Hipoxia-Isquemia Encefálica , Animales , Ratas , Hipoxia-Isquemia Encefálica/tratamiento farmacológico , Hipoxia-Isquemia Encefálica/metabolismo , Hipoxia-Isquemia Encefálica/patología , Animales Recién Nacidos , Leuprolida/farmacología , Leuprolida/uso terapéutico , Factor de Necrosis Tumoral alfa , Enfermedades Neuroinflamatorias , Ratas Wistar , Factores Inmunológicos , Ansiedad/tratamiento farmacológico , Ansiedad/etiologíaRESUMEN
PURPOSE: Conventional therapies and surgery remain the standard treatment for breast cancer. However, combating the eventual development of metastasis is still a challenge. Newcastle disease virus (NDV) is one of the various species of viruses under clinical evaluation as a vector for oncolytic, gene-, and immune-stimulating therapies. The purpose of this study was to evaluate the antitumor activity of a recombinant NDV (rNDV-P05) in a breast cancer murine model. METHODS: Tumors were induced by injecting the cellular suspension (4T1 cell line) subcutaneously. The virus strain P05 was applied three times at intervals of seven days, starting seven days after tumor induction, and was completed 21 days later. Determination of tumor weight, spleen index, and lung metastasis were done after sacrificing the mice. Serum levels of interferon (IFN)-α, IFN-γ, tumor necrosis factor (TNF)-α, and TNF-related apoptosis-inducing ligand (TRAIL) were quantified by enzyme-linked immunosorbent assay. CD8+ infiltrated cells were analyzed by immunofluorescence. RESULTS: rNDV-P05 showed a route-of-administration-dependent effect, demonstrating that the systemic administration of the virus significantly reduces the tumor mass and volume, spleen index, and abundance of metastatic clonogenic colonies in lung tissue, and increases the inhibition rate of the tumor. The intratumoral administration of rNDV-P05 was ineffective for all the parameters evaluated. Antitumor and antimetastatic capability of rNDV-P05 is mediated, at least partially, through its immune-stimulatory effect on the upregulation of TNF-α, TRAIL, IFN-α, and IFN-γ, and its ability to recruit CD8+ T cells into tumor tissue. CONCLUSION: Systemic treatment with rNDV-P05 decreases the tumoral parameters in the breast cancer murine model.
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GPR55 is an orphan receptor whose endogenous agonists include lysophosphatidylinositol (LPI) and Nacetylethanolamides (NAEs), such as palmitoylethanolamide (PEA) and anandamide. Furthermore, its physiology in the central nervous system involves motor coordination, procedural and spatial memory, pain, and anxiety, among others. Recent reports indicate that systemic injections of O1602 (a GPR55 and GPR18 agonist) blocked the reinforcing effects of morphine and nicotine in the conditioned place preference (CPP) paradigm, suggesting a possible participation of peripheral and/or central GPR55/GPR18 in brain reward/antireward systems. In this pilot study, the endogenous GPR55 agonists LPI and PEA, the highly selective GPR55 synthetic agonist ML184 or the selective GPR55 antagonist ML193 were injected to examine their pharmacological effects on the reinforcing actions of nicotine in the CPP paradigm. Our preliminary study shows that injections of LPI, PEA, ML184 and ML193 interfered with the change in place preference induced by nicotine via mechanisms that remain to be identified (which probably include central GPR55).
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Nicotina , Receptores Acoplados a Proteínas G , Derivados de la Morfina , Nicotina/farmacología , Proyectos Piloto , Receptores de CannabinoidesRESUMEN
AIMS: To determine if a continuous administration of leuprolide acetate (LA), a synthetic agonist for the gonadotrophin-releasing hormone receptor, facilitates the recovery of urinary function in spinal cord injured male rats. MAIN METHODS: Male Wistar rats were randomized into spinal cord injury (SCI; n = 7), SCI with continuous administration of LA for two weeks via implantation of a subcutaneous osmotic pump (SCI + LA; n = 7), Sham SCI (SH-SCI; n = 6) or no surgery (Intact; n = 6) groups. Micturition, hind-limb nociception and locomotor behaviors were analyzed before and after surgical procedures on days 7, 14, 21 and 28. After behavioral studies, electromyography of the external urethral sphincter (EUS-EMG) and cystometric (CMG) studies were performed in all groups. KEY FINDINGS: SCI significantly decreased frequency of voids and CMG parameters (p < 0.001), abolished the bursting activity of the EUS during CMG, significantly increased hind limb sensory threshold and decreased locomotor performance in comparison to the other groups (p < 0.001). Continuous LA treatment significantly increased the frequency of voids and improved CMG parameters (p < 0.001), exhibiting bursting EUS activity during CMGs, and enhanced locomotor performance in comparison to SCI rats (p < 0.001). SIGNIFICANCE: SCI severely affected behavioral and functional micturition processes, including sensory and locomotor functions. Systemic and uninterrupted treatment with LA improves the recovery of micturition behavior and the synergistic function of the EUS. Furthermore, sensory and locomotor responses were also improved in SCI rats. This procedure may have a therapeutic potential to facilitate urinary function recovery in patients with SCI.
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Traumatismos de la Médula Espinal , Micción , Animales , Masculino , Ratas , Leuprolida/farmacología , Ratas Wistar , Médula Espinal , Traumatismos de la Médula Espinal/tratamiento farmacológico , UretraRESUMEN
This paper presents a method for pixel-wise classification applied for the first time on hippocampus histological images. The goal is achieved by representing pixels in a 14-D vector, composed of grey-level information and moment invariants. Then, several popular machine learning models are used to categorize them, and multiple metrics are computed to evaluate the performance of the different models. The multilayer perceptron, random forest, support vector machine, and radial basis function networks were compared, achieving the multilayer perceptron model the highest result on accuracy metric, AUC, and F 1 score with highly satisfactory results for substituting a manual classification task, due to an expert opinion in the hippocampus histological images.
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Hipocampo/anatomía & histología , Hipocampo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Algoritmos , Animales , Biología Computacional , Humanos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Interpretación de Imagen Asistida por Computador/estadística & datos numéricos , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Aprendizaje Automático , Masculino , Microscopía , Modelos Anatómicos , Redes Neurales de la Computación , Ratas , Ratas Sprague-Dawley , Máquina de Vectores de SoporteRESUMEN
The expression of the gonadotrophin-releasing hormone receptor expression on pituitary gonadotrophs in humans is well characterized. In nervous system they have also been found in hippocampi and cerebral cortex. However, gonadotrophin-releasing hormone receptor expression in human spinal cord has not been reported. This study was to analyze the gonadotrophin-releasing hormone receptor expression in human spinal cord by immunohistochemistry, mRNAs by reverse transcriptase polymerase chain reaction, cDNA cloning and Western blot. The results show immunoreactive material to gonadotrophin-releasing hormone receptor in motoneurons of the spinal cord. Further, the study revealed that spinal cord expressed the gonadotrophin-releasing hormone receptor mRNA. The amplicon sequence corresponds to 100% of identity to GenBank. In Western blot, a band of 37 kDa were found in extracts of spinal cord and placenta as a control. In conclusion, human spinal cord expresses gonadotrophin-releasing hormone receptor analyzed through immunohistochemistry, the expression of its mRNA, cloning its cDNA and Western blot analysis. The presence of gonadotrophin-releasing hormone receptor in the spinal cord suggests the possibility of an extrapituitary functional role independent of reproductive system.
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Receptores LHRH/metabolismo , Médula Espinal/metabolismo , Adulto , Secuencia de Bases , Femenino , Humanos , Inmunohistoquímica , Masculino , Neuronas Motoras/metabolismo , Placenta/metabolismo , Embarazo , ARN Mensajero/metabolismo , Receptores LHRH/genética , Médula Espinal/citologíaRESUMEN
Lead exposure is known to affect the pituitary-thyroid axis. Likewise, ascorbic acid (AA) has a protective action against lead poisoning. We examine the protective role of AA in lead-induced damage to the thyroid gland. The Wistar rats were divided into three groups: control that received 0.2% AA in drinking water throughout the experiment (15 days), intoxicated with lead acetate (20 mg/kg) intraperitoneally every 48 h for 15 days, and the experimental group treated with lead acetate and 0.2% AA in drinking water throughout the experiment. Plasma thyroid-stimulating hormone, triiodothyronine, thyroxine, and lead were determined. The thyroid gland was weighed, then epithelial cell height and nuclear volume were measured on histological slides. The results show that AA reduced the thyroid atrophy caused by lead acetate, as well as the loss of weight of the gland. In addition, it prevented the decrease of the hormone triiodothyronine, although the thyroxine hormone remained lower than the control values ââand the thyroid-stimulating hormone remains high. Our results indicated that AA could play a protective role in lead poisoning in the thyroid gland.
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It has been reported that the Gonadotropin-releasing hormone (GnRH) and its agonist leuprolide acetate (LA) can act as promoters of nerve regeneration. The aim of this study is to evaluate the effect of LA in a complete transection model. Sciatic nerve injury (SNI) was performed using a complete nerve transection and immediately repaired by epineural sutures. Rats were divided into three groups: SHAM, SNI treated with LA (SNI + LA) or saline solution (SNI + SS) for 5 weeks. Sciatic nerve regeneration was evaluated by kinematic gait analyzes, electrophysiological, morphological and biochemical tests. SNI + LA group had a functional recovery in kinematic gait, an increase in ankle angle value and a faster walking speed, compound muscle action potential amplitude, nerve conduction velocity (NCV). Furthermore, the number of myelinated axons and microtubule-associated protein 2 (MAP-2) expression were also higher compared to SS group. In conclusion, LA treatment improves of gait, walking speed, NCV, axons morphometry and MAP-2 expression in rats with sciatic nerve complete transection. These results suggest that LA can be a potential treatment for peripheral nerve injuries.
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Hormona Liberadora de Gonadotropina/agonistas , Leuprolida/administración & dosificación , Regeneración Nerviosa/efectos de los fármacos , Traumatismos de los Nervios Periféricos/patología , Nervio Ciático/efectos de los fármacos , Nervio Ciático/lesiones , Animales , Axones/efectos de los fármacos , Axones/patología , Locomoción/efectos de los fármacos , Masculino , Traumatismos de los Nervios Periféricos/prevención & control , Ratas Wistar , Nervio Ciático/patologíaRESUMEN
BACKGROUND: Electromyographic studies have shown that external anal sphincter activity is modified in response to distension in animals with spinal cord injury. Gonadotropin-releasing hormone and its agonist leuprolide acetate have neurotrophic properties in animals with spinal cord injury. AIM: This study was to determine the effects of leuprolide acetate treatment on electromyographic activity of the external anal sphincter and anorectal manometry in ovariectomized rats with spinal cord injury. METHODS: Adult ovariectomized rats were divided in three groups: (a) sham of spinal cord injury, (b) spinal cord injury treated with saline solution, and (c) spinal cord injury treated with leuprolide acetate. The spinal cord injury was induced by clamping at level T9. Leuprolide acetate dosage of 10 µg/kg was proctored intramuscular for 5 weeks, commencing the day after the lesion. Electromyography of the external anal sphincter, anorectal manometry, and volume of the cecum were evaluated in all groups. RESULTS: The electromyographic study of the external anal sphincter activity showed a significant improvement in injured rats treated with leuprolide acetate. Manometric analysis and cecum volume data obtained in animals with leuprolide acetate were very similar to those found in the sham group. CONCLUSIONS: These results demonstrate that leuprolide acetate treatment improves the neurogenic colon in ovariectomized rats with spinal cord injury.
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Canal Anal/efectos de los fármacos , Hormona Liberadora de Gonadotropina/agonistas , Leuprolida/farmacología , Intestino Neurogénico/fisiopatología , Ovariectomía , Recto/efectos de los fármacos , Traumatismos de la Médula Espinal/fisiopatología , Canal Anal/fisiopatología , Animales , Ciego/efectos de los fármacos , Ciego/fisiopatología , Electromiografía , Femenino , Manometría , Intestino Neurogénico/etiología , Ratas , Ratas Wistar , Recto/fisiopatología , Traumatismos de la Médula Espinal/complicacionesRESUMEN
The aim of this study was to determine whether chronic administration of GnRH improves performance of learning tasks and expression of spinophilin in the hippocampus of gonadectomized old rats. Eighteen-month-old male Wistar rats were used and divided into three groups: control (intact rats); gonadectomized; and gonadectomizedâ¯+â¯GnRH. The latter group was injected intramuscularly with GnRH (100â¯nM) twice a day for five weeks. The learning tasks we used were the novel object recognition task (NOR), elevated T-maze (ETM) and active avoidance test (AAT). Results showed that in NOR and ETM learning tasks, gonadectomized rats treated with GnRH had a significantly better performance than gonadectomized rats without treatment. GnRH-treated gonadectomized rats displayed performance comparable to that of intact rats. Furthermore, the expression of spinophilin in the hippocampus of gonadectomized rats treated with GnRH increased with respect to untreated gonadectomized rats. In conclusion, the chronic administration of GnRH improves learning in old gonadectomized rats. It is possible that the mechanism could involve a greater number of dendritic contacts associated with a higher expression of spinophilin.
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Castración , Hormona Liberadora de Gonadotropina/administración & dosificación , Hormona Liberadora de Gonadotropina/fisiología , Hipocampo/metabolismo , Aprendizaje/fisiología , Factores de Edad , Animales , Hipocampo/efectos de los fármacos , Aprendizaje/efectos de los fármacos , Masculino , Proteínas de Microfilamentos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Ratas WistarRESUMEN
Antitumor conventional treatments including chemo/radiotherapy result in several side effects and non-specificity. Therapies including the use of oncolytic viruses, particularly the Newcastle disease virus (NDV), have emerged as an attractive alternative due to their capacity to kill cancer cells directly or through stimulation of the immune system. In the present study, a commercial vaccine composed of a recombinant attenuated NDV strain P05 (rNDV-P05) was assessed for antitumor and immunostimulatory activity. Firstly, hemagglutination activity was evaluated at different pH and temperature conditions. Then, cancer cell lines and peripheral blood mononuclear cells (PBMC) were co-cultured with or without rNDV-P05 and cytoplasmic nucleosomes were measured by enzyme-linked immunosorbent assay (ELISA) as an apoptosis indicator. Antitumor cytokines produced by PBMC in response to the virus were analyzed by ELISA and reverse transcription quantitative polymerase chain reaction. Characterization of rNDV-P05 indicates that the virus is slightly sensible to acid and basic pH, and stable at temperatures no greater than 42°C. The majority of cell lines developed apoptosis in co-culture with rNDV-P05 in a dose-time dependent manner. The highest level of HeLa, HCC1954 and HepG2 cell apoptosis was at 48 h/50 hemagglutination units (HU), and HL-60 was 24 h/50 HU. A549 cell line and PBMC did not show sensitivity to apoptosis by the virus. PBMC from healthy donors stimulated with the rNDV-P05 increased significantly the levels of interferon (IFN)-α, IFN-γ, tumor necrosis factor (TNF)-α and soluble TNF-related apoptosis-inducing ligand in culture supernatants, as well as their mRNA expression. These results demonstrate that the pro-apoptotic effect of rNDV-P05 and its magnitude is specific to particular tumor cell lines and is not induced on PBMC; and the virus stimulates the expression of several key antitumor cytokines. This study promotes the use of rNDV-P05 in an alternate application of different viral strains during virotherapy with NDV.
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It has been previously described the presence of GnRH receptor in spinal cord neurons of rat embryos and adult rats. However, the functional role of these receptors has not been studied. In this work, the effect of GnRH on neurite outgrowth and cytoskeletal protein expression in cultured spinal cord neurons of rat embryos was analyzed. Specifically, neurofilaments of 68 and 200 kDa by immunoblot assays and spinophilin mRNA expression by RT-PCR. Results show that GnRH stimulates neurite outgrowth in addition to an increase in neurofilaments and spinophilin expression. These findings suggest that GnRH may play a role as neuromodulator in neuronal plasticity and that could be considered as a potential factor for neuronal regeneration in spinal cord injuries.
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Axones/efectos de los fármacos , Hormona Liberadora de Gonadotropina/farmacología , Filamentos Intermedios/efectos de los fármacos , Neuritas/efectos de los fármacos , Proyección Neuronal/efectos de los fármacos , Médula Espinal/efectos de los fármacos , Animales , Axones/metabolismo , Células Cultivadas , Femenino , Proteínas de Neurofilamentos/metabolismo , Ratas Wistar , Receptores LHRH/metabolismo , Médula Espinal/embriología , Médula Espinal/metabolismoRESUMEN
OBJECTIVE: Recent findings have shown that gonadotropin-releasing hormone (GnRH) administration in an animal model of multiple sclerosis (experimental autoimmune encephalomyelitis, EAE) improves clinical signs of locomotion. The present study was designed to determine whether the administration of the synthetic analog of GnRH, leuprolide acetate (LA) - besides its effects on clinical signs of locomotion - also has an effect on the activation/expression levels of molecular markers of EAE, namely transcription nuclear factor (NF)-κB and the proinflammatory cytokines IL-1ß, IL-17A, IL-23 and TNF-α. METHODS: EAE spinal cords were collected from control and LA-administered rats. Lumbar sections were processed at four different time points during the course of the disease to analyze NF-κB activation by chemiluminescent Western blot, and during the EAE recovery phase to evaluate proinflammatory cytokine levels by quantitative real-time PCR. RESULTS: It was found that LA administration to EAE rats promoted a significant reduction of NF-κB activation during the course of the disease and also decreased the mRNA expression levels of the proinflammatory cytokines IL-1ß, IL-17A and TNF-α in the EAE recovery phase; both effects are consistent with the decrease in the severity of clinical signs of locomotion induced by the treatment. CONCLUSION: LA causes a reduction in the severity of locomotor activity, as well as in the activation of NF-κB and the number of proinflammatory markers in rats with EAE. These results suggest the use of this agonist as a potential therapeutic approach for multiple sclerosis.
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Antiinflamatorios/uso terapéutico , Encefalomielitis Autoinmune Experimental/complicaciones , Leuprolida/uso terapéutico , Mielitis/tratamiento farmacológico , Mielitis/etiología , FN-kappa B/metabolismo , Animales , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/inmunología , Femenino , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , FN-kappa B/genética , Ovariectomía , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas Lew , Factores de Tiempo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The organophosphate and carbamate pesticides methyl-parathion and carbaryl have a common action mechanism: they inhibit acetylcholinesterase enzyme by blocking the transmission of nerve impulses. However, they can alter the expression of exocytotic membrane proteins (SNARE), by modifying release of neurotransmitters and other substances. This study evaluated the adverse effects of the pesticides methyl-parathion and carbaryl on expression of SNARE proteins: Syntaxin-1, Syntaxin-4 and SNAP-23 in freshwater rotifer Brachionus calyciflorus. Protein expression of these three proteins was analyzed before and after exposure to these two pesticides by Western Blot. The expression of Syntaxin-1, Syntaxin-4 and SNAP-23 proteins in B. calyciflorussignificantly decreases with increasing concentration of either pesticides. This suggests that organophosphates and carbamates have adverse effects on expression of membrane proteins of exocytosis by altering the recognition, docking and fusion of presynaptic and vesicular membranes involved in exocytosis of neurotransmitters. Our results demonstrate that the neurotoxic effect of anticholinesterase pesticides influences the interaction of syntaxins and SNAP-25 and the proper assembly of the SNARE complex.
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Carbaril/farmacología , Insecticidas/farmacología , Metil Paratión/farmacología , Rotíferos/efectos de los fármacos , Animales , Inhibidores de la Colinesterasa/farmacología , Proteínas Qa-SNARE/metabolismo , Rotíferos/enzimología , Sintaxina 1/metabolismoRESUMEN
The organophosphate and carbamate pesticides methyl-parathion and carbaryl have a common action mechanism: they inhibit acetylcholinesterase enzyme by blocking the transmission of nerve impulses. However, they can alter the expression of exocytotic membrane proteins (SNARE), by modifying release of neurotransmitters and other substances. This study evaluated the adverse effects of the pesticides methyl-parathion and carbaryl on expression of SNARE proteins: Syntaxin-1, Syntaxin-4 and SNAP-23 in freshwater rotifer Brachionus calyciflorus. Protein expression of these three proteins was analyzed before and after exposure to these two pesticides by Western Blot. The expression of Syntaxin-1, Syntaxin-4 and SNAP-23 proteins in B. calyciflorussignificantly decreases with increasing concentration of either pesticides. This suggests that organophosphates and carbamates have adverse effects on expression of membrane proteins of exocytosis by altering the recognition, docking and fusion of presynaptic and vesicular membranes involved in exocytosis of neurotransmitters. Our results demonstrate that the neurotoxic effect of anticholinesterase pesticides influences the interaction of syntaxins and SNAP-25 and the proper assembly of the SNARE complex.(AU)
Os pesticidas organofosforados e carbamatos metil- paration e carbaril tem um mecanismo de ação comum: eles inibem a enzima acetilcolinesterase, bloqueando a transmissão dos impulsos nervosos. No entanto, eles podem alterar a expressão de proteínas de membrana de exocitose (SNARE), através da modificação da libertação de neurotransmissores e outras substâncias. Este estudo avaliou os efeitos adversos dos pesticidas metil- paration e carbaril sobre a expressão de proteínas SNARE: Sintaxina -1, Sintaxina-4 e SNAP-23 em rotíferos de água doce Brachionus calyciflorus. A expressão destas três proteínas foi analisada antes e depois da exposição a estes dois pesticidas por Western Blot. A expressão das proteínas Sintaxina-1, Sintaxina-4 e SNAP-23 em B. calyciflorus diminui significativamente com o aumento da concentração de ambos os pesticidas. Isto sugere que os organofosfatos e carbamatos têm efeitos adversos sobre a expressão de proteínas de membrana de exocitose, alterando o reconhecimento, de encaixe e fusão de membranas pré-sinápticas e vesiculares envolvidas na exocitose de neurotransmissores. Nossos resultados demonstram que o efeito neurotóxico de pesticidas anticolinesterásicos influencia a interação de sintaxinas e SNAP-25 e a montagem correta do complexo SNARE.(AU)
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Animales , Carbaril/farmacología , Insecticidas/farmacología , Metil Paratión/farmacología , Rotíferos , Inhibidores de la Colinesterasa/farmacología , Proteínas Qa-SNARE/metabolismo , Rotíferos/enzimología , Sintaxina 1/metabolismoRESUMEN
Several studies have shown that gonadotropin-releasing hormone (GnRH) have extra-pituitary roles, including neurotrophic effects. This study was to evaluate the effects of GnRH treatment on the spinal cord injury (SCI) of rats. Ovariectomized rats were divided into: sham SCI surgery (Sham), SCI treated with saline solution (SCI + SS), and SCI treated with GnRH (SCI + GnRH). The SCI was induced by compression. One day after the lesion, SCI + GnRH group was injected with GnRH (60 µg/kg/twice/day; i.m.) for 15 days and the other groups with saline solution. To kinematic gait analysis, length and velocity of the stride were measured. In spinal cord, axonal morphometry and spared white and gray matter were analyzed by histochemistry. Protein expression of spinophilin was evaluated by western blot. The results showed that, 5 weeks after the injury, the group of animals treated with GnRH, significantly increased the length and velocity of the stride compared to SCI + SS group and they were similar to Sham group. In spinal cord, GnRH treatment increased the number and caliber of nerve axons and in the case of white matter, spared tissue was significantly higher than those animals treated with saline solution. The expression of spinophilin in spinal cord of SCI + GnRH group was slightly increased with respect to those not treated. In conclusion, GnRH treatment improves recovery of gait and decreases histopathological damage in the injured spinal cord of rat. These findings suggest that GnRH acts as a neurotrophic factor and can be used as a potential therapeutic agent for treatment of SCI.
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Hormona Liberadora de Gonadotropina/uso terapéutico , Recuperación de la Función , Traumatismos de la Médula Espinal/tratamiento farmacológico , Traumatismos de la Médula Espinal/patología , Animales , Relación Dosis-Respuesta a Droga , Femenino , Hormona Liberadora de Gonadotropina/farmacología , Ratas , Ratas Sprague-Dawley , Recuperación de la Función/efectos de los fármacos , Traumatismos de la Médula Espinal/fisiopatología , Resultado del TratamientoRESUMEN
Mast cells and histamine participate in toxic effects of hairs from some caterpillars. This study reports that a crude extract of Morpheis ehrenbergii caterpillar hairs induces in vitro mast cells activation, triggers the release of histamine and causes a rapid urticarial reaction in the rat skin. Heating of the extract abolishes the inflammatory reaction. These results suggest that the use of antihistamines may improve the adverse skin reactions caused by the Mexican caterpillar M. ehrenbergii.
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Mariposas Diurnas/química , Mezclas Complejas/toxicidad , Mastocitos/inmunología , Urticaria/inducido químicamente , Animales , Mezclas Complejas/administración & dosificación , Mezclas Complejas/análisis , Mezclas Complejas/inmunología , Azul de Evans , Histamina/metabolismo , Inyecciones Intradérmicas , Larva/química , Mastocitos/metabolismo , Ratas , Rojo de Rutenio , Pruebas de ToxicidadRESUMEN
Gonadotrophin-releasing hormone (GnRH), a well known hypothalamic neuropeptide, has been reported to possess neurotrophic properties. Leuprolide acetate, a synthetic analogue of GnRH is considered to be a very safe and tolerable drug and it has been used for diverse clinical applications, including the treatment of prostate cancer, endometriosis, uterine fibroids, central precocious puberty and in vitro fertilization techniques. The present study was designed to determine whether Leuprolide acetate administration, exerts neurotrophic effects on clinical signs, body weight gain, neurofilaments (NFs) and myelin basic protein (MBP) expression, axonal morphometry and cell infiltration in spinal cord of experimental autoimmune encephalomyelitis (EAE) rats. In this work, we have found that Leuprolide acetate treatment decreases the severity of clinical signs of locomotion, induces a significantly greater body weight gain, increases the MBP and NFs expression, axonal area and cell infiltration in EAE animals. These results suggest the use of this agonist as a potential therapeutic approach for multiple sclerosis.
Asunto(s)
Encefalomielitis Autoinmune Experimental/prevención & control , Hormona Liberadora de Gonadotropina/agonistas , Leuprolida/farmacología , Esclerosis Múltiple/tratamiento farmacológico , Animales , Femenino , Leuprolida/uso terapéutico , Ratas , Ratas Endogámicas LewRESUMEN
It was reported that the hypothalamic decapeptide, gonadotropin-releasing hormone (GnRH) produces neurotrophic effects and that the spinal cord possesses GnRH receptors. The aim of the present study was to determine whether administration of GnRH improves locomotor activity, urinary function and neurofilament (NFs) protein expression after spinal cord injury (SCI) in ovariectomized rats. SCI was induced by balloon inflation model resulting in paraplegia. Locomotion was evaluated according to the Basso, Beattie, and Bresnahan Scale. Rats were subjected to bladder compression, twice daily until bladder reflex was established. NFs of 68, 160 and 200 kDa from spinal cords were analyzed by electrophoresis. GnRH (60 µg/kg) or physiologic NaCl solution was administered at 1 day after SCI and then daily for 15 days and the functional evaluation was realized for 5 weeks. Our results indicate that locomotor activity, restoration of urinary dysfunction and NFs expression of 160 and 200 kDa were improved in SCI animals given GnRH compared to those without treatment. These findings suggest that GnRH acts as a neurotrophic factor and may be used as a potential therapeutic agent for treatment of SCI.