RESUMO
The central exacerbating factor in the pathophysiology of ischemic-reperfusion acute kidney injury (AKI) is oxidative stress. Lipid peroxidation and DNA damage in ischemia are accompanied by the formation of 3-nitrotyrosine, a biomarker for oxidative damage. DNA double-strand breaks (DSBs) may also be a result of postischemic AKI. γH2AX(S139) histone has been identified as a potentially useful biomarker of DNA DSBs. On the other hand, hypoxia-inducible factor (HIF) is the "master switch" for hypoxic adaptation in cells and tissues. The aim of this research was to evaluate the influence of hyperbaric oxygen (HBO) preconditioning on antioxidant capacity estimated by FRAP (ferric reducing antioxidant power) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay, as well as on oxidative stress parameter 3-nitrotyrosine, and to assess its effects on γH2AX(S139), HIF-1α, and nuclear factor-κB (NF-κB) expression, in an experimental model of postischemic AKI induced in spontaneously hypertensive rats. The animals were divided randomly into three experimental groups: sham-operated rats (SHAM, n = 6), rats with induced postischemic AKI (AKI, n = 6), and group exposed to HBO preconditioning before AKI induction (AKI + HBO, n = 6). A significant improvement in the estimated glomerular filtration rate, eGFR, in AKI + HBO group (p < 0.05 vs. AKI group) was accompanied with a significant increase in plasma antioxidant capacity estimated by FRAP (p < 0.05 vs. SHAM group) and a reduced immunohistochemical expression of 3-nitrotyrosine and γH2AX(S139). Also, HBO pretreatment significantly increased HIF-1α expression (p < 0.001 vs. AKI group), estimated by Western blot and immunohistochemical analysis in kidney tissue, and decreased immunohistochemical NF-κB renal expression (p < 0.01). Taking all of these results together, we may conclude that HBO preconditioning has beneficial effects on acute kidney injury induced in spontaneously hypertensive rats.
Assuntos
Injúria Renal Aguda , Oxigenoterapia Hiperbárica , Traumatismo por Reperfusão , Animais , Ratos , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Antioxidantes , Biomarcadores , Dano ao DNA , Rim , NF-kappa B , Estresse Oxidativo , Oxigênio , Ratos Endogâmicos SHRRESUMO
A growing body of evidence suggests that hyperbaric oxygenation (HBO) may affect the activity of adult neural stem cells (NSCs). Since the role of NSCs in recovery from brain injury is still unclear, the purpose of this study was to investigate the effects of sensorimotor cortex ablation (SCA) and HBO treatment (HBOT) on the processes of neurogenesis in the adult dentate gyrus (DG), a region of the hippocampus that is the site of adult neurogenesis. Ten-week-old Wistar rats were divided into groups: Control (C, intact animals), Sham control (S, animals that underwent the surgical procedure without opening the skull), SCA (animals in whom the right sensorimotor cortex was removed via suction ablation), and SCA + HBO (operated animals that passed HBOT). HBOT protocol: pressure applied at 2.5 absolute atmospheres for 60 min, once daily for 10 days. Using immunohistochemistry and double immunofluorescence labeling, we show that SCA causes significant loss of neurons in the DG. Newborn neurons in the subgranular zone (SGZ), inner-third, and partially mid-third of the granule cell layer are predominantly affected by SCA. HBOT decreases the SCA-caused loss of immature neurons, prevents reduction of dendritic arborization, and increases proliferation of progenitor cells. Our results suggest a protective effect of HBO by reducing the vulnerability of immature neurons in the adult DG to SCA injury.
Assuntos
Lesões Encefálicas , Oxigenoterapia Hiperbárica , Células-Tronco Neurais , Ratos , Animais , Ratos Wistar , Células-Tronco Neurais/fisiologia , Hipocampo , Neurônios/fisiologia , Neurogênese/fisiologia , Giro DenteadoRESUMO
Ischemia-reperfusion injury (IRI) is a frequent cause of AKI, resulting in vasoconstriction, cellular dysfunction, inflammation and the induction of oxidative stress. DNA damage, including physical DNA strand breaks, is also a potential consequence of renal IRI. The histone H2A variants, primary H2AX and H2AZ participate in DNA damage response pathways to promote genome stability. The aim of this study was to evaluate the immunohistochemical pattern of histone H2A variants' (H2AX, γH2AX(S139), H2AXY142ph and H2AZ) expression in an experimental model of ischemia-reperfusion-induced acute kidney injury in spontaneously hypertensive rats. Comparing the immunohistochemical nuclear expression of γH2AX(S139) and H2AXY142ph in AKI, we observed that there is an inverse ratio of these two histone H2AX variants. If we follow different regions from the subcapsular structures to the medulla, there is an increasing extent gradient in the nuclear expression of H2AXY142ph, accompanied by a decreasing nuclear expression of γH2AX. In addition, we observed that different structures dominated when γH2AX and H2AXY142ph expression levels were compared. γH2AX was expressed only in the proximal tubule, with the exception of when they were dilated. In the medulla, H2AXY142ph is predominantly expressed in the loop of Henle and the collecting ducts. Our results show moderate sporadic nuclear H2AZ expression mainly in the cells of the distal tubules and the collecting ducts that were surrounded by dilated tubules with PAS (periodic acid-Schiff stain)-positive casts. These findings may indicate the degree of DNA damage, followed by postischemic AKI, with potential clinical and prognostic implications regarding this condition.
Assuntos
Injúria Renal Aguda , Traumatismo por Reperfusão , Ratos , Animais , Histonas/metabolismo , Rim/metabolismo , Injúria Renal Aguda/genética , Injúria Renal Aguda/metabolismo , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , Reperfusão , Isquemia/metabolismo , Modelos TeóricosRESUMO
Renal ischemia and reperfusion (I/R) injury is the most common cause of acute kidney injury (AKI). Pathogenesis of postischemic AKI involves hemodynamic changes, oxidative stress, inflammation process, calcium ion overloading, apoptosis and necrosis. Up to date, therapeutic approaches to treat AKI are extremely limited. Thus, the aim of this study was to evaluate the effects of hyperbaric oxygen (HBO) preconditioning on citoprotective enzyme, heme oxygenase-1 (HO-1), pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins expression, in postischemic AKI induced in normotensive Wistar and spontaneously hypertensive rats (SHR). The animals were randomly divided into six experimental groups: SHAM-operated Wistar rats (W-SHAM), Wistar rats with induced postischemic AKI (W-AKI) and Wistar group with HBO preconditioning before AKI induction (W-AKI + HBO). On the other hand, SHR rats were also divided into same three groups: SHR-SHAM, SHR-AKI and SHR-AKI + HBO. We demonstrated that HBO preconditioning upregulated HO-1 and anti-apoptotic Bcl-2 protein expression, in both Wistar and SH rats. In addition, HBO preconditioning improved glomerular filtration rate, supporting by significant increase in creatinine, urea and phosphate clearances in both rat strains. Considering our results, we can also say that even in hypertensive conditions, we can expect protective effects of HBO preconditioning in experimental model of AKI.
Assuntos
Injúria Renal Aguda/prevenção & controle , Heme Oxigenase (Desciclizante)/metabolismo , Oxigenoterapia Hiperbárica/métodos , Hipertensão/complicações , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/patologia , Injúria Renal Aguda/urina , Animais , Creatinina/metabolismo , Creatinina/urina , Modelos Animais de Doenças , Humanos , Hipertensão/fisiopatologia , Hipertensão/terapia , Rim/irrigação sanguínea , Rim/patologia , Rim/fisiopatologia , Masculino , Oxigênio/administração & dosagem , Fosfatos/metabolismo , Fosfatos/urina , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Eliminação Renal/fisiologia , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/urina , Regulação para Cima , Ureia/metabolismo , Ureia/urinaRESUMO
Traumatic brain injury (TBI) is a main cause of death and disabilities in young adults. Although learning and memory impairments are a major clinical manifestation of TBI, the consequences of TBI on the hippocampus are still not well understood. In particular, how lesions to the sensorimotor cortex damage the hippocampus, to which it is not directly connected, is still elusive. Here, we study the effects of sensorimotor cortex ablation (SCA) on the hippocampal dentate gyrus, by applying a highly sensitive gray-level co-occurrence matrix (GLCM) analysis. Using GLCM analysis of granule neurons, we discovered, in our TBI paradigm, subtle changes in granule cell (GC) morphology, including textual uniformity, contrast, and variance, which is not detected by conventional microscopy. We conclude that sensorimotor cortex trauma leads to specific changes in the hippocampus that advance our understanding of the cellular underpinnings of cognitive impairments in TBI. Moreover, we identified GLCM analysis as a highly sensitive method to detect subtle changes in the GC layers that is expected to significantly improve further studies investigating the impact of TBI on hippocampal neuropathology.
Assuntos
Lesões Encefálicas , Giro Denteado/lesões , Giro Denteado/patologia , Hipocampo/patologia , Neurônios/patologia , Animais , Modelos Animais de Doenças , Masculino , Fotomicrografia , Ratos WistarRESUMO
Background: Acute kidney injury (AKI) as a consequence of ischemia is a common clinical event that can lead to unacceptably high morbidity and mortality. Hyperbaric oxygen (HBO2) preconditioning has been shown to prevent ischemia-reperfusion injury (IRI) in different tissues. Objectives: The aim of our study was to compare the effects of HBO2 preconditioning on renal hemodynamics, kidney function and oxidative stress in normotensive and spontaneously hypertensive rats that suffered kidney IRI. Methods: An experiment was performed on Wistar (normotensive) and spontaneously hypertensive rats (SHR). The animals were divided into the following experimental groups: sham-operated rats and rats with or without HBO2 preconditioning 24 hours before post-ischemic AKI induction. Treated rats were placed into experimental HBO2 chambers and exposed to pure oxygen twice a day for two consecutive days (2.026 bar of oxygen) for 60 minutes. AKI was performed the next morning. The right kidney was removed and the renal ischemia was performed by clamping the left renal artery for 45 minutes. Results: In this study, HBO2 preconditioning significantly improved disturbed renal hemodynamics, major markers of kidney function in plasma (creatinine, urea and phosphate) as well as antioxidant enzymes (superoxide dismutase and catalase) activities in erythrocytes after AKI induction. Also, HBO2 preconditioning decreased lipid peroxidation in plasma after ischemic AKI. Positive effects were observed in both strains of rats. Conclusions: Our results suggest that HBO2 treatment improves renal hemodynamic and kidney function and decreases oxidative stress of Wistar and SHR rats with an AKI episode. Furthermore, it also implies that pre-existing hypertension does not affect the beneficial effects of HBO2 preconditioning.
Assuntos
Injúria Renal Aguda/prevenção & controle , Oxigenoterapia Hiperbárica , Precondicionamento Isquêmico/métodos , Rim/irrigação sanguínea , Traumatismo por Reperfusão/prevenção & controle , Animais , Catalase/sangue , Creatinina/sangue , Masculino , Estresse Oxidativo , Fosfatos/sangue , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Superóxido Dismutase/sangue , Ureia/sangueRESUMO
Fractal and grey level co-occurrence matrix (GLCM) analysis represent two mathematical computer-assisted algorithms that are today thought to be able to accurately detect and quantify changes in tissue architecture during various physiological and pathological processes. However, despite their numerous applications in histology and pathology, their sensitivity, specificity and validity regarding evaluation of brain tissue remain unclear. In this article we present the results indicating that certain parameters of fractal and GLCM analysis have high discriminatory ability in distinguishing two morphologically similar regions of rat hippocampus: stratum lacunosum-moleculare and stratum radiatum. Fractal and GLCM algorithms were performed on a total of 240 thionine-stained hippocampus micrographs of 12 male Wistar albino rats. 120 digital micrographs represented stratum lacunosum-moleculare, and another 120 stratum radiatum. For each image, 7 parameters were calculated: fractal dimension, lacunarity, GLCM angular second moment, GLCM contrast, inverse difference moment, GLCM correlation, and GLCM variance. GLCM variance (VAR) resulted in the largest area under the Receiver operating characteristic (ROC) curve of 0.96, demonstrating an outstanding discriminatory power in analysis of stratum lacunosum-moleculare (average VAR equaled 478.1 ± 179.8) and stratum radiatum (average VAR of 145.9 ± 59.2, p < 0.0001). For the criterion VAR ≤ 227.5, sensitivity and specificity were 90% and 86.7%, respectively. GLCM correlation as a parameter also produced large area under the ROC curve of 0.95. Our results are in accordance with the findings of our previous study regarding brain white mass fractal and textural analysis. GLCM algorithm as an image analysis method has potentially high applicability in structural analysis of brain tissue cytoarcitecture.
Assuntos
Algoritmos , Fractais , Hipocampo/anatomia & histologia , Animais , Fenotiazinas/metabolismo , Curva ROC , RatosRESUMO
The exact mechanisms by which treatment with hyperbaric oxygen (HBOT) exerts its beneficial effects on recovery after brain injury are still unrevealed. Therefore, in this study we investigated the influence of repetitive HBOT on the reactive astrogliosis and expression of mediators of inflammation after cortical stab injury (CSI). CSI was performed on male Wistar rats, divided into control, sham, and lesioned groups with appropriate HBO. The HBOT protocol was as follows: 10 minutes of slow compression, 2.5 atmospheres absolute (ATA) for 60 minutes, and 10 minutes of slow decompression, once a day for 10 consecutive days. Data obtained using real-time polymerase chain reaction, Western blot, and immunohistochemical and immunofluorescence analyses revealed that repetitive HBOT applied after the CSI attenuates reactive astrogliosis and glial scarring, and reduces expression of GFAP (glial fibrillary acidic protein), vimentin, and ICAM-1 (intercellular adhesion molecule-1) both at gene and tissue levels. In addition, HBOT prevents expression of CD40 and its ligand CD40L on microglia, neutrophils, cortical neurons, and reactive astrocytes. Accordingly, repetitive HBOT, by prevention of glial scarring and limiting of expression of inflammatory mediators, supports formation of more permissive environment for repair and regeneration.
Assuntos
Lesões Encefálicas/metabolismo , Oxigenoterapia Hiperbárica , Animais , Modelos Animais de Doenças , Molécula 1 de Adesão Intercelular/metabolismo , Masculino , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Wistar , Vimentina/metabolismoRESUMO
This aim of this study was to assess the discriminatory value of fractal and grey level co-occurrence matrix (GLCM) analysis methods in standard microscopy analysis of two histologically similar brain white mass regions that have different nerve fiber orientation. A total of 160 digital micrographs of thionine-stained rat brain white mass were acquired using a Pro-MicroScan DEM-200 instrument. Eighty micrographs from the anterior corpus callosum and eighty from the anterior cingulum areas of the brain were analyzed. The micrographs were evaluated using the National Institutes of Health ImageJ software and its plugins. For each micrograph, seven parameters were calculated: angular second moment, inverse difference moment, GLCM contrast, GLCM correlation, GLCM variance, fractal dimension, and lacunarity. Using the Receiver operating characteristic analysis, the highest discriminatory value was determined for inverse difference moment (IDM) (area under the receiver operating characteristic (ROC) curve equaled 0.925, and for the criterion IDM≤0.610 the sensitivity and specificity were 82.5 and 87.5%, respectively). Most of the other parameters also showed good sensitivity and specificity. The results indicate that GLCM and fractal analysis methods, when applied together in brain histology analysis, are highly capable of discriminating white mass structures that have different axonal orientation.
Assuntos
Corpo Caloso/anatomia & histologia , Giro do Cíngulo/anatomia & histologia , Histocitoquímica/métodos , Processamento de Imagem Assistida por Computador/métodos , Microscopia/métodos , Animais , Curva ROC , Ratos , Sensibilidade e EspecificidadeRESUMO
Despite constant achievements in treatment, acute kidney injury (AKI) remains a significant public health problem and a cause of mortality in the human population. In developed countries, AKI is a significant and frequent hospital complication, especially among patients admitted to intensive care units, where mortality rates can reach up to 50%. In addition, AKI has been implicated as an independent risk factor for the development of chronic kidney disease. Hyperbaric oxygenation (HBO) has been used as a primary or adjunctive therapy for the past 50 years, both in experimental and clinical studies. HBO is a treatment in which the patient is occasionally exposed to 100% oxygen at a pressure greater than atmospheric pressure at sea level. However, despite decades of extensive research, the potentially beneficial effects of this therapeutic approach are still not fully understood, although many potential mechanisms have been proposed, such as antioxidative, anti-inflammatory, anti-apoptotic, etc. Furthermore, the low cost and insignificant adverse events make HBO a potentially important strategy in the prevention and treatment of different diseases. Considering all of this, this review highlights the potential role of HBO in maintaining cellular homeostasis disrupted due to AKI, caused in different experimental models.
Assuntos
Injúria Renal Aguda , Oxigenoterapia Hiperbárica , Oxigenoterapia Hiperbárica/métodos , Injúria Renal Aguda/terapia , Humanos , AnimaisRESUMO
BACKGROUND: Thyroid dysfunctions as well as sleep abnormalities are usually followed by neurological, psychiatric and/or behavioral disorders. On the other hand, changes in the brain adenosine triphosphatases (ATPases) and acetylcholinesterase (AChE) activities show significant importance in pathogenetic pathways in the evolution of numerous neuropsychiatric diseases. METHODS: This study aimed to evaluate the in vivo simultaneous effects of hypothyroidism and paradoxical sleep deprivation for 72 h on synaptosomalATPases and AChE activities of whole rat brains. In order to induce hypothyroidism, 6-n-propyl-2-thiouracil was administrated in drinking water during 21 days. The modified multiple platform method was used to induce paradoxical sleep deprivation. The AChE and ATPases activities were measured using spectrophotometric methods. RESULTS: Hypothyroidism significantly increased the activity of Na+/K+-ATPase compared to other groups, while at the same time significantly decreased AChE activity compared to the CT and SD groups. Paradoxical sleep deprivation significantly increased AChE activity compared to other groups. The simultaneous effect of hypothyroidism and sleep deprivation reduced the activity of all three enzymes (for Na+/K+-ATPase between HT/SD and HT group p < 0.0001, SD group p < 0.001,CT group p = 0.013; for ecto-ATPases between HT/SD and HT group p = 0.0034, SD group p = 0.0001, CT group p = 0.0007; for AChE between HT/SD and HT group p < 0.05, SD group p < 0.0001, CT group p < 0.0001). CONCLUSIONS: The effect of simultaneous existence of hypothyroidism and paradoxical sleep deprivation reduces the activity of the Na+/K+-ATPase, ecto-ATPases, and AChE, what is different from individual effect of hypothyroidism and paradoxical sleep deprivation itself. This knowledge could help in the choice of appropriate therapy in such condition.
Assuntos
Acetilcolinesterase , Hipotireoidismo , Ratos , Animais , Acetilcolinesterase/metabolismo , Privação do Sono/complicações , Privação do Sono/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Ratos Wistar , Sono REM , Hipotireoidismo/complicações , Hipotireoidismo/metabolismo , Encéfalo/metabolismoRESUMO
OBJECTIVE: To investigate whether hyperbaric oxygenation (HBO) can improve the recovery of motor functions in rats after suction ablation of the right sensorimotor cortex. METHODS: The experimental paradigm implies the following groups: Control animals (C), Control + HBO (CHBO), Sham controls (S), Sham control + HBO (SHBO), Lesion group (L), right sensorimotor cortex was removed by suction, Lesion + HBO (LHBO). Hyperbaric protocol: pressure applied 2.5 atmospheres absolute, for 60 minutes, once a day for 10 days. A beam walking test and grip strength meter were used to evaluate the recovery of motor functions. Expression profiles of growth-associated protein 43 (GAP43) and synaptophysin (SYP) were detected using immunohistochemistry. RESULTS: The LHBO group achieved statistically superior scores in the beam walking test compared to the L group. Additionally, the recovery of muscle strength of the affected hindpaw was significantly enhanced after HBO treatment. Hyperbaric oxygenation induced over-expression of GAP43 and SYP in the neurons surrounding the lesion site. CONCLUSIONS: Data presented suggest that hyperbaric oxygen therapy can intensify neuroplastic responses by promoting axonal sprouting and synapse remodelling, which contributes to the recovery of locomotor performances in rats. This provides the perspective for implementation of HBO in clinical strategies for treating traumatic brain injuries.
Assuntos
Lesões Encefálicas/metabolismo , Oxigenoterapia Hiperbárica , Atividade Motora , Plasticidade Neuronal , Animais , Lesões Encefálicas/fisiopatologia , Modelos Animais de Doenças , Proteína GAP-43/metabolismo , Imuno-Histoquímica , Masculino , Condicionamento Físico Animal , Ratos , Sinaptofisina/metabolismoRESUMO
AIM: To evaluate the effect of hyperbaric oxygen therapy (HBOT) on superoxide dismutase 2 (SOD2) expression pattern after the cortical stab injury (CSI). METHODS: CSI was performed on 88 male Wistar rats, divided into control, sham, lesioned, and HBO groups. HBOT protocol was the following: pressure applied was 2.5 absolute atmospheres, for 60 minutes, once a day for consecutive 3 or 10 days. The pattern of SOD2 expression and cellular localization was analyzed using real-time polymerase chain reaction, Western blot, and double-label fluorescence immunohistochemistry. Neurons undergoing degeneration were visualized with Fluoro-Jade®B. RESULTS: CSI induced significant transient increase in SOD2 protein levels at day 3 post injury, which was followed by a reduction toward control levels at post-injury day 10. At the same time points, mRNA levels for SOD2 in the injured cortex were down-regulated. Exposure to HBO for 3 days considerably down-regulated SOD2 protein levels in the injured cortex, while after 10 days of HBOT an up-regulation of SOD2 was observed. HBOT significantly increased mRNA levels for SOD2 at both time points compared to the corresponding L group, but they were still lower than in controls. Double immunofluorescence staining revealed that 3 days after CSI, up-regulation of SOD2 was mostly due to an increased expression in reactive astrocytes surrounding the lesion site. HBOT attenuated SOD2 expression both in neuronal and astroglial cells. Fluoro-Jade®B labeling showed that HBOT significantly decreased the number of degenerating neurons in the injured cortex. CONCLUSION: HBOT alters SOD2 protein and mRNA levels after brain injury in a time-dependent manner.
Assuntos
Lesões Encefálicas/enzimologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Oxigenoterapia Hiperbárica , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Animais , Western Blotting , Lesões Encefálicas/terapia , Regulação para Baixo , Técnica Indireta de Fluorescência para Anticorpo , Imuno-Histoquímica , Masculino , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Fatores de TempoRESUMO
Oxidative stress has been considered as a central aggravating factor in the development of postischemic acute kidney injury (AKI). The aim of this study was to perform the immunohistochemical analysis of 4-hydroxynonenal (4-HNE), neutrophil gelatinase-associated lipocalin (NGAL), and heme oxygenase-1 (HO-1) tissue expression after apocynin (APO) treatment and hyperbaric oxygenation (HBO) preconditioning, applied as single or combined protocol, in postischemic acute kidney injury induced in spontaneously hypertensive rats (SHR). Twenty-four hours before AKI induction, HBO preconditioning was carried out by exposing to pure oxygen (2.026 bar) twice a day, for 60 min in two consecutive days. Acute kidney injury was induced by removal of the right kidney while the left renal artery was occluded for 45 min by atraumatic clamp. Apocynin was applied in a dose of 40 mg/kg body weight, intravenously, 5 min before reperfusion. We showed increased 4-HNE renal expression in postischemic AKI compared to Sham-operated (SHAM) group. Apocynin treatment, with or without HBO preconditioning, improved creatinine and phosphate clearances, in postischemic AKI. This improvement in renal function was accompanied with decreased 4-HNE, while HO-1 kidney expression restored close to the control group level. NGAL renal expression was also decreased after apocynin treatment, and HBO preconditioning, with or without APO treatment. Considering our results, we can say that 4-HNE tissue expression can be used as a marker of oxidative stress in postischemic AKI. On the other hand, apocynin treatment and HBO preconditioning reduced oxidative damage, and this protective effect might be expected even in experimental hypertensive condition.
RESUMO
Renal ischemia/reperfusion injury is a common cause of acute kidney injury (AKI) and hypertension might contribute to the increased incidence of AKI. The purpose of this study was to investigate the effects of single and combined hyperbaric oxygen (HBO) preconditioning and NADPH oxidase inhibition on oxidative stress, kidney function and structure in spontaneously hypertensive rats (SHR) after renal ischemia reperfusion injury. HBO preconditioning was performed by exposing to pure oxygen (2.026 bar) twice a day for two consecutive days for 60 minutes, and 24h before AKI induction. For AKI induction, the right kidney was removed and ischemia was performed by clamping the left renal artery for 45 minutes. NADPH oxidase inhibition was induced by apocynin (40 mg/kg b.m., intravenously) 5 minutes before reperfusion. AKI significantly increased renal vascular resistance and reduced renal blood flow, which were significantly improved after apocynin treatment. Also, HBO preconditioning, with or without apocynin treatment showed improvement on renal hemodynamics. AKI significantly increased plasma creatinine, urea, phosphate levels and lipid peroxidation in plasma. Remarkable improvement, with decrease in creatinine, urea and phosphate levels was observed in all treated groups. HBO preconditioning, solitary or with apocynin treatment decreased lipid peroxidation in plasma caused by AKI induction. Also, combined with apocynin, it increased catalase activity and solitary, glutathione reductase enzyme activity in erythrocytes. While AKI induction significantly increased plasma KIM- 1 levels, HBO preconditioning, solitary or with apocynin decreased its levels. Considering renal morphology, significant morphological alterations present after AKI induction were significantly improved in all treated groups with reduced tubular dilatation, tubular necrosis in the cortico-medullary zone and PAS positive cast formation. Our results reveal that NADPH oxidase inhibition and hyperbaric oxygen preconditioning, with or without NADPH oxidase inhibition may have beneficial effects, but their protective role should be evaluated in further studies.
Assuntos
Acetofenonas/uso terapêutico , Injúria Renal Aguda/terapia , Inibidores Enzimáticos/uso terapêutico , Oxigenoterapia Hiperbárica/métodos , NADPH Oxidases/antagonistas & inibidores , Traumatismo por Reperfusão/terapia , Injúria Renal Aguda/complicações , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Animais , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Endogâmicos SHR , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologiaRESUMO
The effects of ethanol on epilepsy are very complex. Ethanol can have depressant as well as excitatory effect on different animal models of epilepsy. Systemic administration of homocysteine can trigger seizures. The aim of the present study was to examine the changes of total spectral power density after ethanol alone and together with homocysteine thiolactone in adult rats. Adult male Wistar rats were divided into following groups: 1. saline-injected, (control) C; 2. D, L-homocysteine thiolactone, H (8 mmol/kg); 3. ethanol, E (E(0.5), 0.5 g/kg; E(1), 1 g/kg; E(2), 2 g/kg) and 4. E (E(0.5), E(1), and E(2)) 30 min prior to H, EH (E(0.5)H, E(1)H and E(2)H). For EEG recordings three gold-plated screws were implanted into the skull. Our results demonstrate that ethanol, when applied alone, increased total EEG spectral power density of adult rats with a marked spectrum shift toward low frequency waves. In EH groups, increasing doses of ethanol exhibited a dose-dependent effect upon spectral power density. Ethanol increased EEG spectral power density in E(0.5)H and E(1)H group, comparing to the H group (p > 0.05), the maximal increase was recorded with the lowest ethanol dose applied. The highest dose of ethanol (E(2)H) significantly decreased total power spectra density, comparing to the H group. We can conclude that high doses of ethanol depressed marked increase in EEG power spectrum induced by D,L-homocysteine thiolactone.
Assuntos
Eletroencefalografia , Etanol/farmacologia , Homocisteína/análogos & derivados , Convulsões/induzido quimicamente , Convulsões/fisiopatologia , Animais , Relação Dose-Resposta a Droga , Etanol/uso terapêutico , Homocisteína/farmacologia , Masculino , Ratos , Ratos Wistar , Convulsões/tratamento farmacológico , Fatores de TempoRESUMO
PURPOSE: It is considered that exposure to static magnetic fields (SMF) may have both detrimental and therapeutic effect, but the mechanism of SMF influence on the living organisms is not well understood. Since the adenosine triphosphatases (ATPases) and acetylcholinesterase (AChE) are involved in both physiological and pathological processes, the modulation of Na+/K+-ATPase, ecto-ATPases and AChE activities, as well as oxidative stress responses were followed in synaptosomes isolated from rats after chronic exposure toward differently oriented SMF. MATERIAL AND METHODS: Wistar albino rats were randomly divided into three experimental groups (six animals per group): Up and Down group - exposed to upward and downward oriented SMF, respectively, and Control group. After 50 days, the rats were sacrificed, and synaptosomes were isolated from the whole rat brain and used for testing the enzyme activities and oxidative stress parameters. RESULTS: Chronic exposure to 1 mT SMF significantly increased ATPases, AChE activities, and malondialdehyde (MDA) level in both exposed groups, compared to control values. The significant decrease in synaptosomal catalase activity (1.48 ± 0.17 U/mg protein) induced by exposure to the downward oriented field, compared to those obtained for Control group (2.60 ± 0.29 U/mg protein), and Up group (2.72 ± 0.21 U/mg protein). CONCLUSIONS: It could be concluded that chronic exposure to differently oriented SMF increases ATPases and AChE activities in rat synaptosomes. Since brain ATPases and AChE have important roles in the pathogenesis of several neurological diseases, SMF influence on the activity of these enzymes may have potential therapeutic importance.
Assuntos
Acetilcolinesterase/metabolismo , Adenosina Trifosfatases/metabolismo , Campos Magnéticos/efeitos adversos , Sinaptossomos/enzimologia , Animais , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Sinaptossomos/metabolismo , Fatores de TempoRESUMO
Endometrial sonographic and color doppler features can be used to predict the occurrence of pregnancy in natural or stimulated cycles. Implantation will usually only take place if the endometrium has reach a certain stage of vascularisation and development. The aim of this study was to evaluate endometrial development -- endometrial thickness and reflectivity , subendometrial, endometrial and uterine perfusion, after hyperbaric oxygenation, using transvaginal color doppler. During a three years period 32 women with unexplained infertility were entered into a randomised study. The patients were treated in multiplaced HAUX chamber at pressure of 2.3 ATA during 70 minutes, 7 days consecutively beginning with day 5th of menstrual cycle. The evaluation of effects of hyperbaric oxygen therapy was carried out by transvaginal color doppler sonography which was continuously used starting from 8th day of menstrual cycle until the ovulation in the cycles when the therapy was applied , one month before and one month after the therapy. Folliculometry in the cycles when hyperbaric oxygen therapy at 2.3 ATA was applied, indicated an excellent response of endometrium. Thickness of endometrium at the time of ovulation was 11.0 +/- 2.6 mm. Desirable quality of endometrium was significantly better in the cycle when HBO therapy had been applied (p< 0.001). The doppler flowmetry of the uterine arteries indicated that the uterine blood vessel resistance was slightly higher than expected. Mapping of subendometrial blood vessels in the cycles covered by hyperbaric oxygen therapy showed the intensive capillary network of endometrium with low resistance Ri< 0.45. The oxygen used under higher pressure -- oxygen as a drug , may have an extraordinary significance for better outcome of pregnancy implantation by improving endometrial receptivity. If endometrial receptivity is conditioned by adequate vascularisation and oxygenation, then hyperbaric oxygen therapy is the treatment of choice.
Assuntos
Endométrio/irrigação sanguínea , Oxigenoterapia Hiperbárica , Infertilidade Feminina/terapia , Útero/irrigação sanguínea , Adulto , Implantação do Embrião , Endométrio/diagnóstico por imagem , Feminino , Humanos , Ciclo Menstrual/fisiologia , Ultrassonografia Doppler em Cores , Útero/diagnóstico por imagemRESUMO
Three distinct approaches are currently used in assessing acid-base disorders: the traditional - physiological or bicarbonate-centered approach, the base-excess approach, and the "modern" physicochemical approach proposed by Peter Stewart, which uses the strong ion difference (particularly the sodium chloride difference) and the concentration of nonvolatile weak acids (particularly albumin) and partial pressure of carbon dioxide (pCO(2)) as independent variables in the assessment of acid-base status. The traditional approach developed from the pioneering work of Henderson and Hasselbalch and the base-excess are still most widely used in clinical practice, even though there are a number of problems identified with this approach. The approach works well clinically and is recommended for use whenever serum total protein, albumin and phosphate concentrations are normal. Although Stewart's approach has been largely ignored by physiologists, it is increasingly used by anesthesiologists and intensive care specialists, and is recommended for use whenever serum's total protein, albumin or phosphate concentrations are markedly abnormal, as in critically ill patients. Although different in their concepts, the traditional and modern approaches can be seen as complementary, giving in principle, the same information about the acid-base status.
Assuntos
Desequilíbrio Ácido-Base/diagnóstico , Proteínas Sanguíneas/análise , Íons/análise , Desequilíbrio Ácido-Base/sangue , Humanos , Concentração de Íons de HidrogênioRESUMO
Body composition represents an unbreakable unity of the human body basic structure elements and involves a relative representation of the various constituent elements of the human total body weight. It is well known that body composition changes under the influence of continuous physical activity, and, therefore, it is one of the major components of fitness, and general health of the athletes. Therefore, this topic has become a major field of interest for many exercise and sport scientists as well as clinicians who specialize not only in different training methods but also in the prevention of and rehabilitation from major injuries. To date, having considered issues of accuracy, repeatability and utility, there is no universally applicable criterion or 'gold standard' methodology for body composition assessment in athletes. The main objective of this review was to give a short overview of methods for body composition analysis in athletes and to show and compare the latest data on their usefulness and reliability in order to find the best solution for practical everyday work.