RESUMEN
Abstract The effects of Rheum ribes on lead acetate levels and hepatic biochemical factors due to lead acetate toxicity were investigated. Forty male Wistar rats were designated into four groups: Control; lead acetate (receiving in drinking water at 0.6 g/L, daily); hydroalcoholic extract groups (200 and 400 mg/kg doses, gavage, once daily). Treatments were conducted for 10 days. On the 11th day, blood samples were collected to measure lead acetate levels and biochemical factors. Liver tissue samples were examined for histopathological changes. Lead serum levels were increased in lead acetate-treated rats (p<0.001). Lead acetate treatment was associated with a significant increase in liver tissue damage (p<0.001), while R. ribes extract prevented liver tissue damage (p<0.05). The levels of alanine aminotransferase and aspartate aminotransferase were significantly lower in the groups lead acetate + extract (two doses) than in the lead acetate group (p<0.001 and P<0.01, respectively), but alkaline phosphatase level, prothrombin time, partial thromboplastin time and international normalized ratio were not different between the lead acetate + extract groups and the lead acetate group. The results showed the inhibitory role of R. ribes on lead-induced hepato-toxicity. The results make Rhubarb a good candidate to protect against the deleterious effect of chronic lead intoxication after complementary studies
Asunto(s)
Animales , Masculino , Ratas , Rheum/efectos adversos , Extractos Vegetales/análisis , Polygonaceae/clasificación , Plomo/toxicidadRESUMEN
Kidney injury molecule-1 (KIM-1) is a membrane receptor upregulated in the proximal tubule cells following various types of kidney injuries. Notably, studies have suggested a correlation between KIM-1 expression and extracellular signal-regulated kinase (ERK) activation. In this study, we aimed to investigate the association between the kidney overexpression pattern of cytoplasmic phosphorylated-ERK (p-ERK) protein and increased urinary KIM-1 levels in rats exposed to gentamicin or lead acetate, both at the end of toxic exposure and after a 4-week recovery period. Although other proteins were evaluated, only kidney overexpression of cytoplasmic p-ERK protein correlated with increased urinary KIM-1 levels. For both toxic substances, the increased urinary KIM-1 levels corresponded with kidney inflammation. Our results suggest that KIM-1 and p-ERK share a common mechanism in kidney injury mediated by both toxic substances that induce proximal tubule damage.
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Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/orina , Moléculas de Adhesión Celular/orina , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Gentamicinas/toxicidad , Túbulos Renales Proximales/lesiones , Túbulos Renales Proximales/metabolismo , Compuestos Organometálicos/toxicidad , Transducción de Señal/efectos de los fármacos , Animales , Canales de Calcio/metabolismo , Proteínas de Transporte de Catión/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Citoplasma/metabolismo , Modelos Animales de Enfermedad , Histonas/metabolismo , Masculino , Fosforilación , Ratas , Ratas Wistar , Canales Catiónicos TRPV/metabolismoRESUMEN
OBJECTIVE: To analyze a medical prescription from the 18th century in the New Kingdom of Granada, nowadays Colombia, used in the treatment of soft tissue injuries, specifically wounds and skin ulcers. METHOD: A documentary search was conducted in the Cipriano Rodríguez Santamaria Historical Archive of the Octavio Arizmendi Posada Library, at Universidad de La Sabana (Chía, Colombia), and a review of the literature available in electronic databases. RESULTS AND CONCLUSION: The colonial medical prescription mentions the benefits of lead acetate in poultice for inflammatory processes in general and skin alterations. However, its use is not recommended due to its potential cytotoxic effect at tissue level in various organs.
OBJETIVO: Analizar una receta médica del siglo XVIII en el Nuevo Reino de Granada, hoy República de Colombia, utilizada para el tratamiento de las lesiones de tejidos blandos, específicamente heridas y úlceras en la piel. MÉTODO: Se realizó una búsqueda documental en el Archivo Histórico Cipriano Rodríguez Santamaría de la Biblioteca Octavio Arizmendi Posada, en la Universidad de La Sabana (Chía, Colombia), y se hizo una revisión de la literatura disponible en bases de datos electrónicas. RESULTADOS Y CONCLUSIÓN: En la receta médica colonial se mencionan los beneficios del uso de lo que se interpreta como acetato de plomo en cataplasma para procesos inflamatorios en general y alteraciones de la piel. Sin embargo, en la actualidad se conoce su potencial efecto citotóxico tisular en diversos órganos.
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Extractos Vegetales , Prescripciones , Humanos , Extractos Vegetales/uso terapéuticoRESUMEN
BACKGROUND: Lead induces endothelial dysfunction and hypertension in humans and animals. Seven-day exposure to a low dose in rats reduces vasocontractile responses and increases nitric oxide (NO) bioavailability. We hypothesized that this occurs by angiotensin II receptors (AT1/AT2) activation. MATERIALS AND RESULTS: Wistar rats were exposed to lead acetate (1 st dose 4 µg/100 g, subsequent dose 0.05 µg/100 g/day i.m., 7 days) or saline (control group). Lead acetate exposure reduced the phenylephrine vascular response. Pre-incubations with NO synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME) or phosphatidylinositol 3-kinase (PI3K) inhibitor (wortmannin) increased the contractile response in aortas from lead-treated rats. Pre-incubation with AT2 antagonist (PD123319) restored normal vascular contraction, and both PD123319 or AT1 antagonist (losartan) impeded the potentiated effects of L-NAME and wortmannin. Reinforcing those findings, increased NO bioavailability was blunted by AT1 and AT2 antagonists without summative effect when co-incubated. Finally, to test whether activation of AT1 could upregulate AT2 to increase NO bioavailability rats were simultaneously exposed to lead acetate and treated with losartan (15 mg/kg/day, orally given). Losartan prevented changes on vascular reactivity and endothelial modulation in lead-exposed group. Moreover, incubation with PD123319 had no more effects in aortic from losartan-treated rats. CONCLUSION: Our results suggest that low-dose lead acetate exposure induces an increase of NO involving mainly AT2 receptor activation and the PI3K/Protein Kinase B (PI3K/Akt) pathway. Additionally, we suggest that AT1 activation plays a role in AT2 upregulation, probably as a protective mechanism. Altogether, these effects might contribute to preserving endothelial function against the harmful effects by lead in the vascular system.
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Endotelio Vascular/efectos de los fármacos , Óxido Nítrico/metabolismo , Compuestos Organometálicos/toxicidad , Fosfatidilinositol 3-Quinasa/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptor de Angiotensina Tipo 1/metabolismo , Animales , Aorta Torácica/efectos de los fármacos , Aorta Torácica/metabolismo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Masculino , Ratas Wistar , Transducción de Señal/efectos de los fármacosRESUMEN
OBJECTIVE: The current study investigated the effects of clomiphene citrate on the hypothalamic-pituitary-testicular axis, steroidogenesis, sperm parameters, and testicular antioxidant enzyme activity of male Wistar rats submitted to lead acetate (Pb)-induced reproductive toxicity. METHODS: Twenty adult male Wistar rats were divided into four groups of equal size as follows: Control; Clomid (0.35 mg/kg); Pb (10 mg/kg); and Clomid + Pb. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, testicular 17-ß hydroxysteroid dehydrogenase (17-ß HSD) activity, androgen receptors, catalase activity, superoxide dismutase (SOD), malondialdehyde (MDA), sperm motility, viability, counts and morphology were estimated after oral administration of Clomid and/or lead acetate for 35 consecutive days. Data were analyzed using ANOVA at p<0.05. RESULTS: Lead acetate significantly decreased (p<0.05) serum LH and testosterone levels, testicular 17ß-HSD activity, androgen receptor expression, sperm motility, viability, counts, catalase activity, and SOD when compared with controls. Abnormal sperm morphology and MDA were significantly increased (p<0.05) in the Pb group compared with controls. Clomid co-administrated with lead acetate significantly increased (p<0.05) serum LH, testosterone levels, testicular 17ß-HSD, androgen receptor expression, sperm motility and viability when compared with the group given lead acetate. CONCLUSIONS: The present study suggests that clomiphene citrate may stimulate testicular testosterone synthesis, sperm motility and viability via luteinizing hormone in a context of lead acetate-induced reproductive toxicity.
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Clomifeno/farmacología , Compuestos Organometálicos/toxicidad , Moduladores Selectivos de los Receptores de Estrógeno/farmacología , Espermatozoides/efectos de los fármacos , Testículo/efectos de los fármacos , Animales , Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Masculino , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Wistar , Recuento de Espermatozoides , Motilidad Espermática/efectos de los fármacos , Espermatozoides/metabolismo , Testosterona/sangreRESUMEN
INTRODUCTION: Lead is a multiple organ toxicant and an oxidative-stress inducer. The effect of Costus afer on metal- induced male reprotoxicity has not been previously carried out, hence this study. The present study investigates the protective effect of Costus afer aqueous leave extract on lead- induced reproductive damages in male albino Wistar rats. METHODS: Adult male albino Wistar rats were weighed and separated into five groups of five rats each. Groups 1 & 2 served as normal and toxic controls receiving deionized and leaded (CH3COO)2Pb.3H2O and water respectively. Groups 3, 4 and 5 were given 750, 1500 and 2250mg/kg of Costus afer orally, respectively while receiving Pb2+ water ad libitum for 28 days. RESULTS: The reproductive and antioxidant parameters obtained from the result served as scientific evidence in the study. The result showed non-significant changes in the absolute and relative weights of epididymis and testes in the Pb Group versus the control. Significant increases were recorded in the sperm analysis, blood lead (7.9±1.02; 1.1±0.01) level (BLL), luteinizing hormone (LH) (8.5±1.4:5.5±0.4), and a decrease in follicle stimulating hormone (FSH) (4.5±2.6:6.5±1.65), with non-significant changes in testosterone (TET) (1.3±0.00:1.6±0.2) in the Pb group compared to the control. CONCLUSION: The treatment with Costus afer exhibited dose-dependent significant changes in testicular oxidative stress, hormonal, sperm analysis and histopathological changes induced by lead. Aqueous leaves extract of Costus afer may be protective against lead induced testicular damage.
Asunto(s)
Costus/química , Infertilidad/inducido químicamente , Infertilidad/prevención & control , Intoxicación por Plomo/complicaciones , Extractos Vegetales/farmacología , Sustancias Protectoras/farmacología , Animales , Hormona Folículo Estimulante/sangre , Infertilidad/sangre , Plomo/toxicidad , Intoxicación por Plomo/sangre , Intoxicación por Plomo/tratamiento farmacológico , Intoxicación por Plomo/patología , Hormona Luteinizante/sangre , Masculino , Estrés Oxidativo/efectos de los fármacos , Hojas de la Planta/química , Ratas , Ratas Wistar , Reproducción/efectos de los fármacos , Análisis de Semen , Testículo/efectos de los fármacos , Testículo/fisiología , Testosterona/sangreRESUMEN
Abstract Introduction The literature has reported the association between lead and auditory effects, based on clinical and experimental studies. However, there is no consensus regarding the effects of lead in the auditory system, or its correlation with the concentration of the metal in the blood. Objective To investigate the maturation state of the auditory system, specifically the auditory nerve and brainstem, in rats exposed to lead acetate and supplemented with ferrous sulfate. Methods 30 weanling male rats (Rattus norvegicus, Wistar) were distributed into six groups of five animals each and exposed to one of two concentrations of lead acetate (100 or 400 mg/L) and supplemented with ferrous sulfate (20 mg/kg). The maturation state of the auditory nerve and brainstem was analyzed using Brainstem Auditory Evoked Potential before and after lead exposure. The concentration of lead in blood and brainstem was analyzed using Inductively Coupled Plasma-Mass Spectrometry. Results We verified that the concentration of Pb in blood and in brainstem presented a high correlation (r = 0.951; p < 0.0001). Both concentrations of lead acetate affected the maturation state of the auditory system, being the maturation slower in the regions corresponding to portion of the auditory nerve (wave I) and cochlear nuclei (wave II). The ferrous sulfate supplementation reduced significantly the concentration of lead in blood and brainstem for the group exposed to the lowest concentration of lead (100 mg/L), but not for the group exposed to the higher concentration (400 mg/L). Conclusion This study indicate that the lead acetate can have deleterious effects on the maturation of the auditory nerve and brainstem (cochlear nucleus region), as detected by the Brainstem Auditory Evoked Potentials, and the ferrous sulphate can partially amend this effect.
Resumo Introdução A literatura relatou a associação entre o chumbo e os efeitos auditivos, com base em estudos clínicos e experimentais. No entanto, não há consenso em relação aos efeitos do chumbo no sistema auditivo, ou sua correlação com a concentração do metal no sangue. Objetivo Investigar o estado de maturação do sistema auditivo, especificamente do nervo auditivo e do tronco encefálico, em ratos expostos ao acetato de chumbo e suplementados com sulfato ferroso. Método 30 ratos machos desmamados (Rattus norvegicus, Wistar) foram distribuídos em seis grupos de cinco animais e expostos a uma de duas concentrações de acetato de chumbo (100 ou 400 mg/L) e suplementados com sulfato ferroso (20 mg/kg). O estado de maturação do nervo auditivo e do tronco encefálico foi analisado pelo Potencial Evocado Auditivo do Tronco Encefálico antes e após a exposição ao chumbo. A concentração de chumbo no sangue e tronco encefálico foi analisada utilizando-se Espectrometria de Massa com Plasma Indutivamente Acoplado. Resultados Verificamos que as concentrações de Pb no sangue e no tronco encefálico apresentaram alta correlação (r = 0,951, p < 0,0001). Ambas as concentrações de acetato de chumbo afetaram o estado de maturação do sistema auditivo, a maturação foi mais lenta nas regiões correspondentes à porção do nervo auditivo (onda I) e dos núcleos cocleares (onda II). A suplementação com sulfato ferroso reduziu significativamente a concentração de chumbo no sangue e no tronco encefálico no grupo exposto à menor concentração de chumbo (100 mg/L), mas não para o grupo exposto à maior concentração (400 mg/L). Conclusão Esse estudo indica que o acetato de chumbo pode ter efeitos deletérios na maturação do nervo auditivo e do tronco encefálico (região do núcleo coclear), como detectado pelos potenciais evocados auditivos do tronco encefálico, e que o sulfato ferroso pode diminuir parcialmente esse efeito.
Asunto(s)
Animales , Masculino , Ratas , Compuestos Organometálicos/efectos adversos , Tronco Encefálico/efectos de los fármacos , Compuestos Ferrosos/administración & dosificación , Nervio Coclear/efectos de los fármacos , Plomo/toxicidad , Potenciales Evocados Auditivos del Tronco Encefálico , Ratas Wistar , Modelos Animales , Plomo/sangreRESUMEN
INTRODUCTION: The literature has reported the association between lead and auditory effects, based on clinical and experimental studies. However, there is no consensus regarding the effects of lead in the auditory system, or its correlation with the concentration of the metal in the blood. OBJECTIVE: To investigate the maturation state of the auditory system, specifically the auditory nerve and brainstem, in rats exposed to lead acetate and supplemented with ferrous sulfate. METHODS: 30 weanling male rats (Rattus norvegicus, Wistar) were distributed into six groups of five animals each and exposed to one of two concentrations of lead acetate (100 or 400mg/L) and supplemented with ferrous sulfate (20mg/kg). The maturation state of the auditory nerve and brainstem was analyzed using Brainstem Auditory Evoked Potential before and after lead exposure. The concentration of lead in blood and brainstem was analyzed using Inductively Coupled Plasma-Mass Spectrometry. RESULTS: We verified that the concentration of Pb in blood and in brainstem presented a high correlation (r=0.951; p<0.0001). Both concentrations of lead acetate affected the maturation state of the auditory system, being the maturation slower in the regions corresponding to portion of the auditory nerve (wave I) and cochlear nuclei (wave II). The ferrous sulfate supplementation reduced significantly the concentration of lead in blood and brainstem for the group exposed to the lowest concentration of lead (100mg/L), but not for the group exposed to the higher concentration (400mg/L). CONCLUSION: This study indicate that the lead acetate can have deleterious effects on the maturation of the auditory nerve and brainstem (cochlear nucleus region), as detected by the Brainstem Auditory Evoked Potentials, and the ferrous sulphate can partially amend this effect.
Asunto(s)
Tronco Encefálico/efectos de los fármacos , Nervio Coclear/efectos de los fármacos , Compuestos Ferrosos/administración & dosificación , Plomo/toxicidad , Compuestos Organometálicos/efectos adversos , Animales , Potenciales Evocados Auditivos del Tronco Encefálico , Plomo/sangre , Masculino , Modelos Animales , Ratas , Ratas WistarRESUMEN
Lead acetate is a chemical compound. Sources of human exposure to this metal include many foods, drinking water and dust. The aim of this study was to determine the immunohistochemical and histopathological changes on the face skin after lead acetate application. Wistar Albino rats (180-200 g body weight) were divided into a controlled and lead acetate-exposed group. Rats received lead acetate at 500 ppm in their drinking water for 60 days. Both groups were fed with the same standard food, but lead acetate was added to the drinking water. During the experimental period, blood samples were drawn from the abdominal aorta of the anesthetised animals. At the end of exposure, body weight and blood lead levels were measured. Sections of rat facial skin were examined histopathological and immunohistochemical. In the group treated with lead acetate, minimal to slight multifocal hydropic degeneration of basal cell layer, depending on the thinning of the epidermis, the cellular degeneration in the dermis and a increase in the number of necrotic cells was observed in sebaceous glands of the hair follicle hemorrhage. The immunohistochemical results of the present work demonstrated an increase in Proliferating cell nuclear antigen (PCNA) immunoreactivity in skin specimens from lead acetate treated animals. Vimentin immunoreactivity was very dense in hair follicle of the subepidermal region. It was also strongly stained around the myoepithelial cells surrounding sebaceous and stromal cells.
El acetato de plomo es un compuesto químico. Las fuentes de exposición humana a este metal incluyen una gran variedad de alimentos, agua potable y el polvo. El objetivo fue determinar los cambios inmunohistoquímicos e histopatológicos en la piel de la cara después de la aplicación de acetato de plomo en ratas Wistar albinas (180 a 200 g de peso corporal) las que fueron divididas en un grupo control y otro expuesto al acetato de plomo. Las ratas expuestas recibieron acetato de plomo en dosis de 500 ppm en el agua que bebían durante 60 días. Ambos grupos fueron alimentados con el mismo pellet estándar. Durante el período experimental, se extrajeron muestras de sangre desde la parte abdominal de la aorta con los animales anestesiados. Al final de la exposición, se midió el peso corporal y los niveles de plomo en la sangre. Secciones de piel de la cara se examinaron y estudiaron con procediminetos histopatológicos e inmunohistoquímicos. En el grupo expuesto, se observó una degeneracion hidrópica multifocal desde mínima a ligera de la capa de células basales; dependiendo del adelgazamiento de la epidermis, se observó degeneración celular en la dermis y un aumento en el número de células necróticas en las glándulas sebáceas de folículos pilosos hemorrágicos. Los resultados inmunohistoquímicos demostraron un aumento de inmunoreactividad al antígeno nuclear de células en proliferación (PCNA) en las muestras de piel de los animales tratados con acetato de plomo. La inmunoreactividad a vimentina fue muy densa en los folículos pilosos de la región subepidermal. También se observó una fuerte tinción alrededor de las células mioepiteliales que rodean las células sebáceas y estromales.
Asunto(s)
Animales , Ratas , Compuestos Organometálicos/administración & dosificación , Piel/efectos de los fármacos , Piel/patología , Inmunohistoquímica , Ratas WistarRESUMEN
The aim of this work was to study the effects of sub-lethal exposure of lead acetate on the histopathology of the gills, liver, kidney and muscle and its accumulation in these organs of Clarias gariepinus. Results showed that lead accumulation in the tissues of C. gariepinus was dependent on the exposure period and lead concentration. Gills and liver were the predominant storage tissue and the order of accumulation in tissues was gill > liver > kidney > muscle. Some structural changes were observed in different organs, especially in the gills of the fishes exposed to lead acetate. Epithelial hypertrophy and epithelial lifting were apparent in the gills of exposed fishes. The degeneration of cytoplasm and secondary lamellae was also observed. Necrosis of hepatocytes was apparent. Glomerular expansion and gaps between the muscular bundles were found in the fishes exposed to lead acetate.
RESUMEN
Lead is one of the heavy metals most used in industry. Poisoning due to long-term lead exposure is known as saturnism, and is an occupational illness that has been known for many years. Lead is highly toxic and can compromise the structural and functional patterns of organs and systems. The aim of this study was to examine the lungs and kidneys of fetuses from female Wistar rats exposed to lead acetate. In this study, the lungs and kidneys of 20 fetuses from female rats that had previously been treated with lead acetate were dissected, fixed, embedded in paraffin and stained with hematoxylin and eosin. Macroscopic changes to the shape, color and consistency of organs from fetuses treated with this heavy metal were observed, in comparison with organs from control fetuses. Microscopic lesions characterized by vascular sclerosis, cell atrophy or hyperplasia, progressive interstitial fibrosis, inclusion bodies containing lead acetate and glomerular sclerosis were found in the kidneys. The lesions found in the lungs consisted of destructuring of the parenchyma, impregnation with lead acetate, formation of fibrosis, extravasation of vascular fluids, reduction of the alveolar spaces and formation of alveolar edema. These changes were correlated with the level of lead acetate absorption, as determined using atomic spectrophotometry.
El plomo es un metal pesado utilizado en la industria. El envenenamiento debido a la exposición prolongada por plomo es una enfermedad profesional conocida por muchos años. La toxicidad del plomo es muy expresiva y puede poner en peligro el modelo estructural y funcional de los órganos y sistemas. El objetivo de este estudio fue examinar los pulmones y riñones de fetos de ratas Wistar expuestos al acetato de plomo. En este estudio, 20 fetos de ratas Wistar previamente tratados con acetato de plomo durante la gestación, tuvieron sus órganos disecados, fijados, incluidos en parafina y teñidos con hematoxilina y eosina. Macroscópicamente, los órganos fetales tratados por este metal fueron comparados con los órganos de fetos controles en relación a forma, color y consistencia. Microscópicamente, se encontraron lesiones en el riñón que se caracterizaron por esclerosis vascular, atrofia o hiperplasia de células, fibrosis intersticial progresiva, presencia de cuerpos de inclusión que contenían acetato de plomo y esclerosis glomerular. En el pulmón se observó desorganización del parénquima impregnado con acetato de plomo, formación de fibrosis, líquido intersticial, reducción de los espacios alveolares y edema alveolar. Estos cambios se correlacionaron con el nivel de absorción de acetato de plomo, determinado por espectrometría atómica.
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Ratas , Plomo/toxicidad , Pulmón/anatomía & histología , Pulmón , Riñón/anatomía & histología , Riñón , Anomalías Inducidas por Medicamentos/veterinaria , Ratas Wistar/anatomía & histología , Ratas Wistar/sangre , Peligro CarcinogénicoRESUMEN
The purpose of this study was to investigate the ultrastructural effects of lead on the kidney cortex of rats. Wistar Albino rats (180-200g body weight) were divided into a controlled and lead acetate-exposed group. Rats received lead acetate at 500 ppm in their drinking water for 60 days. Both groups were fed with the same standard food, but lead acetate was added to the drinking water. During the experimental period, blood samples were taken from the abdominal aorta of the anesthetised animals. At the end of exposure, body weight and blood lead levels were measured. The kidney tissue samples were prepared and analyzed by light and transmission electron microscopy. Cortical renal tubules show various degenerative changes with focal tubular necrosis invaded by inflammatory cells. The ultrastructural alterations found in lead acetate-treated rats were a diminution in the amount of filtration slits, increased fusion of foot processes in epithelial cells of the glomeruli, increase of lysosomal structures and pinocytic vesicles as well as large mitochondria in proximal tubule cells.
El propósito de este estudio fue investigar los efectos ultraestructurales del plomo en la corteza renal. Ratas Wistar albinas (180-200g de peso corporal) fueron divididas en grupo control y grupo experimental. Las ratas recibieron 500 ppm de acetato de plomo en el agua potable durante 60 días. Ambos grupos fueron alimentados con el mismo alimento estándar, pero acetato de plomo se le añadió al agua potable al grupo experimental. Durante el período experimental, se tomaron bajo anestesia muestras sanguíneas desde la parte abdominal de la aorta. Al final de la exposición, fueron medidos el peso corporal y los niveles de plomo en la sangre. Fueron preparadas las muestras de tejido renal y se analizaron mediante microscopía de luz y electrónica de transmisión. Los túbulos renales corticales mostraron varios cambios degenerativos con necrosis tubular focal invadida por células inflamatorias. Las alteraciones ultraestructurales encontradas en las ratas tratadas con acetato de plomo correspondieron a una disminución en la cantidad de ranuras de filtración, aumento de la fusión de los procesos podales en las células epiteliales de los glomérulos, aumento de la estructura lisosomal y las vesículas pinocíticas, así como grandes mitocondrias en las células del túbulo proximal.
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Ratas , Corteza Renal/anatomía & histología , Corteza Renal , Corteza Renal/irrigación sanguínea , Corteza Renal/lesiones , Corteza Renal/ultraestructura , Plomo/administración & dosificación , Plomo/fisiología , Plomo/sangre , Plomo/toxicidad , Acetatos/efectos adversos , Acetatos/sangre , Acetatos/toxicidad , Ratas Wistar/anatomía & histología , Ratas Wistar/lesiones , Ratas Wistar/sangreRESUMEN
Chronic lead exposure induces hypertension in humans and animals, affecting endothelial function. However, studies concerning acute cardiovascular effects are lacking. We investigated the effects of acute administration of a high concentration of lead acetate (100 µÌ) on the pressor response to phenylephrine (PHE) in the tail vascular bed of male Wistar rats. Animals were anesthetized with sodium pentobarbital and heparinized. The tail artery was dissected and cannulated for drug infusion and mean perfusion pressure measurements. Endothelium and vascular smooth muscle relaxation were tested with acetylcholine (5 µg/100 µL) and sodium nitroprusside (0.1 µg/100 µL), respectively, in arteries precontracted with 0.1 µM PHE. Concentration-response curves to PHE (0.001-300 µg/100 µL) were constructed before and after perfusion for 1 h with 100 µÌ lead acetate. In the presence of endothelium (E+), lead acetate increased maximal response (Emax) (control: 364.4 ± 36, Pb2+: 480.0 ± 27 mmHg; P < 0.05) and the sensitivity (pD2; control: 1.98 ± 0.07, 2.38 ± 0.14 log mM) to PHE. In the absence of endothelium (E-) lead had no effect but increased baseline perfusion pressure (E+: 79.5 ± 2.4, E-: 118 ± 2.2 mmHg; P < 0.05). To investigate the underlying mechanisms, this protocol was repeated after treatment with 100 µM L-NAME, 10 µM indomethacin and 1 µM tempol in the presence of lead. Lead actions on Emax and pD2 were abolished in the presence of indomethacin, and partially abolished with L-NAME and tempol. Results suggest that acute lead administration affects the endothelium, releasing cyclooxygenase-derived vasoconstrictors and involving reactive oxygen species.