RESUMEN
Carnosine (ß-alanyl-L-histidine) is synthesized in the olfactory system, has antioxidant activity as a scavenger of free radicals and has been reported to have neuroprotective action in diseases which have been attributed to oxidative damage. In neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases, impairment of olfactory function has been described. Vanadium derivatives are environmental pollutants, and its toxicity has been associated with oxidative stress. Vanadium toxicity on the olfactory bulb was reported previously. This study investigates the neuroprotective effect of carnosine on the olfactory bulb in a mice model of vanadium inhalation. Male mice were divided into four groups: vanadium pentoxide (V2 O5 ) [0.02 mol/L] inhalation for one hour twice a week; V2 O5 inhalation plus 1 mg/kg of carnosine administered daily; carnosine only, and the control group that inhaled saline. The olfactory function was evaluated using the odorant test. Animals were sacrificed four weeks after exposure. The olfactory bulbs were dissected and processed using the rapid Golgi method; cytological and ultrastructural analysis was performed and malondialdehyde (MDA) concentrations were measured. The results showed evidence of olfactory dysfunction caused by vanadium exposure and also an increase in MDA levels, loss of dendritic spines and necrotic neuronal death in the granule cells. But, in contrast, vanadium-exposed mice treated with carnosine showed an increase in dendritic spines and a decrease in neuronal death and in MDA levels when compared with the group exposed to vanadium without carnosine. These results suggest that dendritic spine loss and ultrastructural alterations in the granule cells induced by vanadium are mediated by oxidative stress and that carnosine may modulate the neurotoxic vanadium action, improving the olfactory function.
Asunto(s)
Carnosina/farmacología , Fármacos Neuroprotectores/farmacología , Bulbo Olfatorio/efectos de los fármacos , Columna Vertebral/patología , Animales , Modelos Animales de Enfermedad , Síndromes de Neurotoxicidad/tratamiento farmacológico , Bulbo Olfatorio/patología , Estrés Oxidativo/efectos de los fármacos , Columna Vertebral/efectos de los fármacos , Compuestos de Vanadio/farmacologíaRESUMEN
Resumen Las espinas dendríticas constituyen modificaciones de la membrana celular de las dendritas, ricas en actina, cuya morfología se modifica y puede sugerir la presencia de alteraciones en la comunicación neuronal. Las espinas dendríticas cuentan con un aparato espinoso que participa en la regulación del calcio (Ca) intracelular. Reportes recientes mencionan la relación entre el número de espinas y las alteraciones del sueño, estado fisiológico en el que ocurre la consolidación de la memoria. Diversos estudios asocian cambios en su forma y densidad con ciertas patologías. En esta revisión se identifican las características morfológicas de estas y su relación con el desarrollo del sistema nervioso, el sueño y algunas patologías.
Abstract The dendritic spines are dendritic membrane modifications rich in actin, whose morphology changes could suggest modifications in neural communication. These dendritic spines have a spiny-apparatus that regulates the intracellular calcium concentration. Recent reports mention the relationship between the number of spines and certain sleep disorders, the physiologic state in which memory consolidation takes place. Changes in their morphology and density are associated with several pathologies. In this revision we describe the morphological modifications of dendritic spines, their relationship with the development of the nervous system, sleep disorders and some other pathologies.
RESUMEN
Kidney diseases have notably increased in the last few years. This is partially explained by the increase in metabolic syndrome, diabetes, and systemic blood hypertension. However, there is a segment of the population that has neither of the previous risk factors, yet suffers kidney damage. Exposure to atmospheric pollutants has been suggested as a possible risk factor. Air-suspended particles carry on their surface a variety of fuel combustion-related residues such as metals, and vanadium is one of these. Vanadium might produce oxidative stress resulting in the damage of some organs such as the kidney. Additionally, in countries like Mexico, the ingestion of sweetened beverages is a major issue; whether these beverages alone are responsible for direct kidney damage or whether their ingestion promotes the progression of an existing renal damage generates controversy. In this study, we report the combined effect of vanadium inhalation and sweetened beverages ingestion in a mouse model. Forty CD-1 male mice were distributed in 4 groups: control, vanadium inhalation, 30% sucrose in drinking water, and vanadium inhalation plus sucrose 30% in drinking water. Our results support that vanadium inhalation and the ingestion of 30% sucrose induce functional and histological kidney damage and an increase in oxidative stress biomarkers, which were higher in the combined effect of vanadium plus 30% sucrose. The results also support that the ingestion of 30% sucrose alone without hyperglycemia also produces kidney damage.
Asunto(s)
Bebidas/efectos adversos , Enfermedades Renales/inducido químicamente , Estrés Oxidativo/efectos de los fármacos , Sacarosa/efectos adversos , Vanadio/toxicidad , Administración Oral , Animales , Bebidas/análisis , Glucemia , Interacciones Farmacológicas , Riñón/efectos de los fármacos , Riñón/patología , Masculino , Ratones , Distribución Aleatoria , Sacarosa/administración & dosificación , Sacarosa/química , Sacarosa/farmacocinética , Edulcorantes/administración & dosificación , Edulcorantes/efectos adversos , Edulcorantes/análisis , Edulcorantes/farmacocinética , Urinálisis , Vanadio/farmacocinéticaRESUMEN
This study was developed in order to describe the early morphological events observed during the invasion of two pathogenic strains of Acanthamoeba (genotype T4); A. castellanii and A. culbertsoni, at the olfactory meatus and cerebral, pulmonary, renal, hepatic and splenic tissues levels, an in vivo invasion study. Histological and immunohistochemical description of the events at 24, 48, 72, and 96 h postintranasal inoculations of BALB/c mice was performed. A. castellanii showed a higher invasion rate than A. culbertsoni, which was only able to reach lung and brain tissue in the in vivo model. The current study supports previous evidence of lack of inflammatory response during the early stages of infection. Acanthamoeba invasion of the CNS and other organs is a slow and contact-dependent process. The early morphological events during the invasion of amoebae include the penetration of trophozoites into different epithelia: olfactory, respiratory, alveolar space, and renal tubule, which resemble the process of amoebae invasion described in corneal tissue. The data suggest that after reaching the nasal epithelium, trophozoites continued invasion, separating and lifting the most superficial cells, then migrating and penetrating between the cell junctions without causing a cytolytic effect on adjacent cells. These results reaffirm the idea that contact-dependent mechanisms are relevant for amoebae of Acanthamoeba genus regardless of the invasion site.
Asunto(s)
Acanthamoeba/patogenicidad , Amebiasis/patología , Sistema Nervioso Central/parasitología , Túbulos Renales/parasitología , Mucosa Nasal/parasitología , Mucosa Respiratoria/parasitología , Trofozoítos/metabolismo , Animales , Córnea/parasitología , Modelos Animales de Enfermedad , Genotipo , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB CRESUMEN
There are evidences of environmental pollution and health effects. Metals are pollutants implicated in systemic toxicity. One of the least studied effects, but which is currently becoming more important, is the effect of metals on glycemic control. Metals have been implicated as causes of chronic inflammation and oxidative stress and are associated to obesity, hyperglycemia and even diabetes. Arsenic, iron, mercury, lead, cadmium and nickel have been studied as a risk factor for hyperglycemia and diabetes. There is another group of metals that causes hypoglycemia such as vanadium, chromium, zinc and magnesium by different mechanisms. Zinc, magnesium and chromium deficiency is associated with increased risk of diabetes. This review summarizes some metals involved in glycemic control and pretends to alert health professionals about considering environmental metals as an important factor that could explain the poor glycemic control in patients. Further studies are needed to understand this poorly assessed problem.
Asunto(s)
Contaminantes Ambientales/toxicidad , Hiperglucemia/inducido químicamente , Hipoglucemia/inducido químicamente , Metales/toxicidad , Animales , Glucemia/metabolismo , Humanos , Hiperglucemia/metabolismo , Hipoglucemia/metabolismo , Insulina/sangre , Resistencia a la InsulinaRESUMEN
Vanadium (V) is an air pollutant released into the atmosphere by burning fossil fuels. Also, it has been recently evaluated for their carcinogenic potential to establish permissible limits of exposure at workplaces. We previously reported an increase in the number and size of platelets and their precursor cells and megakaryocytes in bone marrow and spleen. The aim of this study was to identify the involvement of Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway and thrombopoietin (TPO) receptor, and myeloproliferative leukemia virus oncogene (Mpl), in megakaryocyte proliferation induced by this compound. Mice were exposed twice a week to vanadium pentoxide inhalation (0.02 M) and were killed at 4th, 6th, and 8th week of exposure. Phosphorylated JAK2 (JAK2 ph), STAT3 (STAT3 ph), STAT5, and Mpl were identified in mice spleen megakaryocytes by cytofluorometry and immunohistochemistry. An increase in JAK2 ph and STAT3 ph, but a decrease in Mpl at 8-week exposure was identified in our findings. Taking together, we propose that the morphological findings, JAK/STAT activation, and decreased Mpl receptor induced by V leads to a condition comparable to essential thrombocythemia, so the effect on megakaryocytes caused by different mechanisms is similar. We also suggest that the decrease in Mpl is a negative feedback mechanism after the JAK/STAT activation. Since megakaryocytes are platelet precursors, their alteration affects platelet morphology and function, which might have implications in hemostasis as demonstrated previously, so it is important to continue evaluating the effects of toxics and pollutants on megakaryocytes and platelets.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Quinasas Janus/metabolismo , Megacariocitos/efectos de los fármacos , Trombocitemia Esencial/genética , Vanadio/toxicidad , Animales , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Relación Dosis-Respuesta a Droga , Quinasas Janus/genética , Masculino , Megacariocitos/citología , Ratones , Fosforilación , Receptores de Trombopoyetina/genética , Receptores de Trombopoyetina/metabolismo , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Trombocitemia Esencial/inducido químicamente , Trombocitemia Esencial/diagnósticoRESUMEN
Particulate matter air pollution has considerably increased during the last decades; vanadium is a transition element adhered to this particulate matter, and the combustion of fossil fuels is the main source in the atmosphere. It has been reported that air pollution and specifically vanadium exposure increases the probability of suffering arrhythmias; however the biological mechanism of such a relationship remains unknown. It has been established that a diminished presence of N-Cadherin alters the Connexin-43 arrangement, and the consequent altered presence of these proteins predisposes to ventricular heart rate problems. We analyzed myocardial histology and the expression of N-Cadherin and Connexin-43 by immunohistochemistry in mouse that inhaled vanadium. Our results showed a significant and progressive reduction in both N-Cadherin and Connexin-43, as well as the presence of meganucleus; myofibrils disruption, and clumping in the exposed groups were also observed. Our findings add more information about a possible explanation for the arrythmogenic effect observed in dwellers of cities with high particulate matter atmospheric pollution.
Asunto(s)
Cadherinas/metabolismo , Conexina 43/metabolismo , Corazón/efectos de los fármacos , Miocardio/metabolismo , Material Particulado/toxicidad , Vanadio/toxicidad , Contaminación del Aire , Animales , Inmunohistoquímica , Masculino , RatonesRESUMEN
Chronic obstructive pulmonary disease (COPD) is an inflammatory disease that arises in response to noxious particles or gases. Associations of genetic polymorphisms in TNF have been reported in Asians and Caucasians, but not in Mestizo populations. A case-control study was conducted in two stages: in the first stage, patients with COPD (COPD group, n=165) and smokers without disease (SNC group, n=165) were included and the TNF promoter sequence was determined using direct sequencing. In the second stage, the identified polymorphisms were validated by real-time polymerase chain reaction (PCR) in COPD (n=260) and SNC (n=506). In the first stage, 11 different sets of "contig" alignments were determined, of which contig 10 was found to be associated with susceptibility (P=5.0E-04, OR [odds ratio] =3.64) and contig 1 with Global Initiative for COPD (GOLD) greater grade (P=1.0E-02, OR =3.82). The single nucleotide polymorphisms found in this region were individually identified; the GA genotypes of rs1800629 (P=0.038, OR =2.07), rs56036015 (P=0.0082, OR =3.18), and rs361525 (P=1.0E-02, OR =4.220) were higher in the COPD group vs the SNC group; after second-stage validation, rs1800629 (P=6.00E-03, OR =2.26) and rs56036015 (P=1.10E-03, OR =2.54) are maintained. There are genetic variants in the TNF promoter associated with increased risk of COPD secondary to smoking and with a higher GOLD grade in the Mexican Mestizo population.
Asunto(s)
Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Enfermedad Pulmonar Obstructiva Crónica/genética , Fumar/efectos adversos , Factor de Necrosis Tumoral alfa/genética , Anciano , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Femenino , Volumen Espiratorio Forzado , Interacción Gen-Ambiente , Predisposición Genética a la Enfermedad , Humanos , Pulmón/fisiopatología , Masculino , México/epidemiología , Persona de Mediana Edad , Oportunidad Relativa , Fenotipo , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Enfermedad Pulmonar Obstructiva Crónica/etnología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Riesgo , Índice de Severidad de la Enfermedad , Fumar/etnología , Capacidad VitalRESUMEN
Malaria continues to be a major global health problem, and over 40% of the world's population is at risk. Severe or complicated malaria is defined by clinical or laboratory evidence of vital organ dysfunction, including dysfunction of the central nervous system (CNS). The pathogenesis of complicated malaria has not been completely elucidated; however, the development of the multiorgan affection seems to play an important role in the disruption of the blood brain barrier (BBB) that protects the CNS against chemical insults. Historically, the BBB has received more attention in the pathogenesis of malaria than have the cerebrospinal fluid-brain barrier (CSFBB) and ependymal cells. This perspective may be misguided because, in the context of disease or toxicity, the CSFBB is more vulnerable to many foreign invaders than are the capillaries. Given the lack on studies of the damage to the CSFBB and ependymal epithelium in experimental murine malaria, the present study evaluated morphological changes in the ependymal cells of CD-1 male mice infected with lethal Plasmodium yoelii yoelii (Pyy) via histopathology and scanning electron microscopy (SEM). Samples were taken two, four and six days post-infection (PI). No lesions were observed upon the initial infection. By the fourth day PI, fourth ventricle ependymal samples exhibited disruptions and roughened epithelia. More severe injuries were observed at six days PI and included thickened cilia and deep separations between the ependymal intercellular spaces. In some of the analyzed areas, the absence of microvilli and cell layer detachment were observed, and some areas exhibited blebbing surfaces. The ependymal cell lesions observed in the CD1 male mice infected with lethal Pyy seemed to facilitate the paracellular permeability of the CSFBB and consequently promote the access of inflammatory mediators and toxic molecules through the barrier, which resulted in damage to the brain tissue. Understanding the mechanism of ependymal disruption during lethal murine malaria could help to elucidate the local and systemic factors that are involved in the pathogenesis of the disease and may provide essential clues for the prevention and treatment of complicated human malaria.
Asunto(s)
Epéndimo/patología , Malaria/patología , Plasmodium yoelii , Animales , Barrera Hematoencefálica/parasitología , Barrera Hematoencefálica/patología , Encéfalo/parasitología , Encéfalo/patología , Recuento de Células , Ventrículos Cerebrales/parasitología , Ventrículos Cerebrales/patología , Malaria/parasitología , Masculino , Mesencéfalo/parasitología , Mesencéfalo/patología , RatonesRESUMEN
Neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases, have olfaction impairment. These pathologies have also been linked to environmental pollutants. Vanadium is a pollutant, and its toxic mechanisms are related to the production of oxidative stress. In this study, we evaluated the effects of inhaled vanadium on olfaction, the olfactory bulb antioxidant, through histological and ultrastructural changes in granule cells. Mice in control group were made to inhale saline; the experimental group inhaled 0.02-M vanadium pentoxide (V2O5) for 1 hr twice a week for 4 weeks. Animals were sacrificed at 1, 2, 3, and 4 weeks after inhalation. Olfactory function was evaluated by the odorant test. The activity of glutathione peroxidase (GPx) and glutathione reductase (GR) was assayed in olfactory bulbs and processed for rapid Golgi method and ultrastructural analysis. Results show that olfactory function decreased at 4-week vanadium exposure; granule cells showed a decrease in dendritic spine density and increased lipofuscin, Golgi apparatus vacuolation, apoptosis, and necrosis. The activity of GPx and GR in the olfactory bulb was increased compared to that of the controls. Our results demonstrate that vanadium inhalation disturbs olfaction, histology, and the ultrastructure of the granule cells that might be associated with oxidative stress, a risk factor in neurodegenerative diseases.
Asunto(s)
Contaminantes Ambientales/toxicidad , Bulbo Olfatorio/metabolismo , Bulbo Olfatorio/patología , Compuestos de Vanadio/administración & dosificación , Compuestos de Vanadio/toxicidad , Administración por Inhalación , Animales , Antioxidantes/metabolismo , Apoptosis/efectos de los fármacos , Espinas Dendríticas/efectos de los fármacos , Espinas Dendríticas/patología , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Masculino , Ratones , Necrosis , Bulbo Olfatorio/efectos de los fármacos , Olfato/efectos de los fármacosRESUMEN
Amyloid beta (Aß) is a peptide of 39-43 amino acids found in large amounts and forming deposits in the brain tissue of patients with Alzheimer's disease (AD). For this reason, it has been implicated in the pathophysiology of damage observed in this type of dementia. However, the role of Aß in the pathophysiology of AD is not yet precisely understood. Aß has been experimentally shown to have a wide range of toxic mechanisms in vivo and in vitro, such as excitotoxicity, mitochondrial alterations, synaptic dysfunction, altered calcium homeostasis, oxidative stress, and so forth. In contrast, Aß has also shown some interesting neuroprotective and physiological properties under certain experimental conditions, suggesting that both physiological and pathological roles of Aß may depend on several factors. In this paper, we reviewed both toxic and protective mechanisms of Aß to further explore what their potential roles could be in the pathophysiology of AD. The complete understanding of such apparently opposed effects will also be an important guide for the therapeutic efforts coming in the future.
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Péptidos beta-Amiloides/farmacología , Péptidos beta-Amiloides/toxicidad , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/toxicidad , Animales , Antioxidantes/farmacología , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacosRESUMEN
Vanadium pentoxide (V(2)O(5)) inhalation effect on platelet function in mice was explored, as well as the in vitro effect on human platelets. Mouse blood samples were collected and processed for aggregometry and flow cytometry to assess the presence of P-selectin and monocyte-platelet conjugates. Simultaneously, human platelets were processed for aggregometry(.) The mouse results showed platelet aggregation inhibition in platelet-rich-plasma (PRP) at four-week exposure time, and normality returned at eight weeks of exposure, remaining unchanged after the exposure was discontinued after four weeks. This platelet aggregation inhibition effect was reinforced with the in vitro assay. In addition, P-selectin preserved their values during the exposure, until the exposure was discontinued during four weeks, when this activation marker increased. We conclude that vanadium affects platelet function, but further studies are required to evaluate its effect on other components of the hemostatic system.
Asunto(s)
Plaquetas/efectos de los fármacos , Plaquetas/fisiología , Compuestos de Vanadio/toxicidad , Administración por Inhalación , Contaminantes Atmosféricos/sangre , Contaminantes Atmosféricos/toxicidad , Animales , Células Cultivadas , Humanos , Masculino , Ratones , Ratones Endogámicos , Selectina-P/metabolismo , Activación Plaquetaria/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Plasma Rico en Plaquetas/efectos de los fármacos , Compuestos de Vanadio/administración & dosificación , Compuestos de Vanadio/sangreRESUMEN
The neuroactive metabolite at the kynunerine pathway, kynurenic acid (KYNA), is a well-known competitive antagonist at the co-agonist glycine site of the N-methyl-D-aspartate receptor (NMDAr), and also decreases the extracellular levels of glutamate by blocking α7-nicotinic acetylcholine receptor (α7-nAchr) located on glutamatergic terminals. KYNA has been often reported to be neuroprotective in different neurotoxic models. The systemic administration of L-kynurenine (L-KYN)--the precursor of KYNA--together with probenecid (PROB)--an inhibitor of organic acids transport--to rodents increases KYNA levels in the brain in a dose-dependent manner. The striatal infusion of the toxin 6-hydroxydopamine (6-OHDA) to rodents is one of the common models used to simulate Parkinson's disease (PD). Different studies have linked PD alterations with excessive glutamatergic transmission in the striatum since NMDAr antagonists exert beneficial effects in PD models. In this work we investigated the effect that a systemic administration of L-KYN+PROB exerted on the toxic model induced by 6-OHDA in rats. PROB (50 mg/kg, i.p.) + L-KYN (75 mg/kg, i.p.) were given to rats for seven consecutive days. On day two of treatment, the animals were infused with a single injection of 6-OHDA (20 µg/2 µl) into the right striatum. Fourteen days post-lesion, rotation behavior was assessed as a marker of motor impairment. The total levels of dopamine (DA) were also estimated in striatal tissue samples of 6-OHDA-treated animals as a neurochemical marker of damage. In addition, twenty eight days post-lesion, the striatal damage was assessed by hematoxylin/eosin staining and immunohistochemistry against glial fibrillary acidic protein (GFAP) in the same animals. Neurodegeneration was also assessed by Fluoro Jade staining. 6-OHDA infusion increased rotation behavior, striatal reactive gliosis and neurodegeneration, while DA levels were decreased. For all markers evaluated, we observed protective effects of L-KYN+PROB on the dopaminergic damage induced by 6-OHDA. Our results suggest that this strategy was useful to mitigate dopaminergic toxicity in the hemiparkinsonian model. The combined use of L-KYN and PROB is a valuable tool to modulate glutamatergic and cholinergic activities, presumably by means of increased levels of endogenous KYNA.
Asunto(s)
Cuerpo Estriado/efectos de los fármacos , Ácido Quinurénico/metabolismo , Quinurenina/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Síndromes de Neurotoxicidad/prevención & control , Oxidopamina/toxicidad , Probenecid/uso terapéutico , Animales , Conducta Animal/efectos de los fármacos , Cuerpo Estriado/metabolismo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Quinurenina/administración & dosificación , Masculino , Fármacos Neuroprotectores/administración & dosificación , Síndromes de Neurotoxicidad/metabolismo , Probenecid/administración & dosificación , Ratas , Ratas WistarRESUMEN
The present study examines the effects of divalent and trivalent Manganese (Mn(2+)/Mn(3+)) mixture inhalation on mice to obtain a novel animal model of Parkinson disease (PD) inducing bilateral and progressive dopaminergic cell death, correlate those alterations with motor disturbances, and determine whether L-DOPA treatment improves the behavior, to ensure that the alterations are of dopaminergic origin. CD-1 male mice inhaled a mixture of Manganese chloride and Manganese acetate, one hour twice a week for five months. Before Mn exposure, animals were trained to perform motor function tests and were evaluated each week after the exposure. By the end of Mn exposure, 10 mice were orally treated with 7.5 mg/kg L-DOPA. After 5 months of Mn mixture inhalation, striatal dopamine content decreased 71%, the SNc showed important reduction in the number of TH-immunopositive neurons, mice developed akinesia, postural instability, and action tremor; these motor alterations were reverted with L-DOPA treatment. Our data provide evidence that Mn(2+)/Mn(3+) mixture inhalation produces similar morphological, neurochemical, and behavioral alterations to those observed in PD providing a useful experimental model for the study of this neurodegenerative disease.
RESUMEN
INTRODUCTION: After unilateral dopamine depletion, some ipsilateral alterations occur and the contralateral structure has been utilized as control. OBJECTIVE: Our aim is to analyse the evolution of the ultrastructural alterations of the ipsilateral and contralateral striata of the 6-hydroxydopamine lesioned rats to demonstrate that the contralateral striatum should not be used as control structure. METHODS: After the surgery and the rotation behavior evaluation, animals were killed from 3 to 120 days after lesioning, and their striata were compared with those of aged rats. RESULTS: The ultrastructural analysis shows increased diameter of the synaptic ending in ipsilateral (since the third day) and contralateral striata (since day 30) and an increase in perforated synaptic contacts. CONCLUSION: Our data suggest that the contralateral striatum should not be taken as control structure at least after 20-30 days after lesioning, as the alterations found here may result in wrong interpretations when comparing with the ipsilateral-lesioned one.
Asunto(s)
Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Lateralidad Funcional/fisiología , Neurópilo/patología , Síndromes de Neurotoxicidad/metabolismo , Síndromes de Neurotoxicidad/patología , Síndromes de Neurotoxicidad/fisiopatología , Adrenérgicos , Animales , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/ultraestructura , Modelos Animales de Enfermedad , Lateralidad Funcional/efectos de los fármacos , Masculino , Microscopía Electrónica de Transmisión/métodos , Neurópilo/ultraestructura , Síndromes de Neurotoxicidad/etiología , Oxidopamina/toxicidad , Ratas , Ratas Wistar , Sinapsis/efectos de los fármacos , Sinapsis/ultraestructura , Factores de TiempoRESUMEN
An increased incidence in ischemic and thromboembolic events in the population of cities with rising air suspended particle pollution has suggested the interaction of some of the components of these particles in the coagulation system. A previous report from our laboratory identified thrombocytosis as a consequence of the subacute and chronic inhalation of vanadium. With this preceding information we decided to evaluate the effects of this element in the spleen and bone marrow in a mouse experimental model. CD-1 male mice inhaled V2O5 0.02 M for one hour twice a week for twelve weeks. The spleen and bone marrow were processed for light microscopy. The increase in quantity and size of megakaryocytes (MKs) in the exposed group in both organs was striking. Also, modifications in the cytoplasm, granule content and nuclear ultrastructure were evident. Our results indicate the influence of vanadium on megakaryopoyesis, an effect which could be the onset of the thrombocytosis previously reported by our group. The modifications in MKs described here suggest that inhaled vanadium could induce megakaryocytic proliferation, which may result in increased production of platelets and increased risk for thromboembolic events.
Asunto(s)
Células de la Médula Ósea/efectos de los fármacos , Megacariocitos/efectos de los fármacos , Material Particulado/toxicidad , Bazo/efectos de los fármacos , Trombopoyesis/efectos de los fármacos , Compuestos de Vanadio/toxicidad , Animales , Células de la Médula Ósea/patología , Proliferación Celular/efectos de los fármacos , Tamaño de la Célula/efectos de los fármacos , Exposición por Inhalación , Masculino , Megacariocitos/patología , Ratones , Modelos Animales , Material Particulado/administración & dosificación , Bazo/patología , Tromboembolia/sangre , Tromboembolia/inducido químicamente , Factores de Tiempo , Compuestos de Vanadio/administración & dosificaciónRESUMEN
Vanadium (V) is a transition metal emitted to the atmosphere during the combustion of fossil fuels. Its current status as an atmospheric pollutant increases the need for information about the effects that this element might have on the reproductive health of exposed populations. The present study investigated changes in testicular ultrastructure following inhalation exposure of male mice to V (as vanadium pentoxide). Tissue V level was constant during the 12-week time period. We observed necrosis of spermatogonium, spermatocytes and Sertoli cells, as well as pseudo-nuclear inclusion and disruption of cellular junctions. Our findings stressed the importance of the hemato-testicular barrier in supporting the function of Sertoli cells and suggest as a possible target of V, tight junction proteins. Further analysis is needed in order to identify the role that reactive oxidative species (ROS) might have on these cellular junctions, and if a specific protein is the target of its toxic effects. The relevance of this report concerns the impact that metal air pollution could have on male fertility in dense cities with vehicular traffic problems.
Asunto(s)
Contaminantes Atmosféricos/toxicidad , Exposición por Inhalación , Testículo/efectos de los fármacos , Testículo/ultraestructura , Compuestos de Vanadio/toxicidad , Contaminantes Atmosféricos/metabolismo , Animales , Núcleo Celular/efectos de los fármacos , Núcleo Celular/ultraestructura , Infertilidad Masculina/inducido químicamente , Masculino , Ratones , Microscopía Electrónica , Necrosis , Túbulos Seminíferos/efectos de los fármacos , Túbulos Seminíferos/ultraestructura , Células de Sertoli/efectos de los fármacos , Células de Sertoli/ultraestructura , Espermatocitos/efectos de los fármacos , Espermatocitos/ultraestructura , Espermatogonias/efectos de los fármacos , Espermatogonias/ultraestructura , Testículo/metabolismo , Uniones Estrechas/efectos de los fármacos , Uniones Estrechas/ultraestructura , Factores de Tiempo , Compuestos de Vanadio/metabolismoRESUMEN
Spatial memory may be severely impaired as a consequence of ageing and neurodegenerative diseases, conditions that include neuronal damage. Vanadium (V) is a metalloid widely distributed in the environment and exerts severe toxic effects on a wide variety of biological systems. Reports about V inhalation toxicity on the CNS are limited, thus the purpose of this study is to determine the effects of Vanadium pentoxide (V(2)O(5)) inhalation (0.02M) on the memory and its correlation with the cytology of the hippocampus CA1. Forty eight CD-1 male mice were trained in spatial memory tasks and inhaled 1h twice a week; after each inhalation animals were evaluated and sacrificed from 1 to 4 weeks, perfused and processed for Golgi method and for ultrastructure evaluation. The cytological analysis consisted in counting the number of dendritic spines of 20 pyramidal neurons of hippocampus CA1, as well as ultrastructural characteristics. Results show that V inhalation produces a time dependent loss of dendritic spines, necrotic-like cell death, and notorious alterations of the hippocampus CA1 neuropile, which correlate with spatial memory impairment. Our data suggest that V induces important cellular and functional alterations, fact that deserves special attention since the concentration's trend of this element in the atmosphere is increasing.
Asunto(s)
Hipocampo , Trastornos de la Memoria/inducido químicamente , Células Piramidales/efectos de los fármacos , Compuestos de Vanadio/administración & dosificación , Administración por Inhalación , Análisis de Varianza , Animales , Conducta Animal/efectos de los fármacos , Dendritas/efectos de los fármacos , Dendritas/ultraestructura , Hipocampo/efectos de los fármacos , Hipocampo/patología , Hipocampo/ultraestructura , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Microscopía Electrónica de Transmisión/métodos , Células Piramidales/ultraestructura , Tiempo de Reacción/efectos de los fármacos , Tinción con Nitrato de Plata/métodos , Factores de TiempoRESUMEN
Reports about vanadium (V) inhalation toxicity on the hematopoietic system, specifically about coagulation are limited. Therefore, we decided to evaluate the effects of V with a complete blood count and morphologic analysis of platelets on blood smears. CD-1 male mice inhaled V2O5 0.02 M 1 h twice weekly over 12 weeks. Blood samples were obtained by direct heart puncture; Wright stained smears were used for platelet quantification. An increase in platelet count from the third week of exposure was observed, as well as the presence of megaplatelets. Our results demonstrate, for the first time, that V induces thrombocytosis and it might correlate with some thromboembolic diseases. Further analysis is needed to evaluate the functionality of these platelets as well as the cause of its increase.
Asunto(s)
Contaminantes Atmosféricos/toxicidad , Trombocitosis/inducido químicamente , Compuestos de Vanadio/toxicidad , Administración por Inhalación , Animales , Masculino , Ratones , Compuestos de Vanadio/administración & dosificaciónRESUMEN
Vanadium is an important environmental and industrial pollutant whose concentrations have increased in the last decades. Due to its status as reproductive toxicant and a microtubule damaging agent, the present study investigated by immunohistochemistry the effect of the inhalation of vanadium pentoxide on gamma-tubulin within somatic and testicular germ cells. Male mice inhaled vanadium pentoxide (V2O5) (0.02 M) 1 h/twice a week for 12 weeks. Our results demonstrated that vanadium accumulates in the testes starting with the initial inhalation (24 h), and this pattern remained until the last week of treatment. In general, vanadium was capable of significantly decreasing the percentage of gamma-tubulin in all analyzed testicular cells (Sertoli, Leydig and germ cells) starting with the first week of treatment. For all cell types studied, regression analysis revealed a negative and significant relationship between the percentage of immunopositive cells to gamma-tubulin and exposure time, showing a time dependent response in all cases. Our findings suggest that alterations on this protein might imply changes in microtubule-involved function such as cell division, which in the testes might lead to damage in the spermatogenesis, leading probably to infertility.