RESUMO
Despite the widespread use of intravenous fluids in acute kidney injury (AKI), solid evidence is lacking. Intravenous fluids mainly improve AKI due to true hypovolaemia, which is difficult to discern at the bedside unless it is very pronounced. Empiric fluid resuscitation triggered only by elevated serum creatinine levels or oliguria is frequently misguided, especially in the presence of fluid intolerance syndromes such as increased extravascular lung water, capillary leak, intra-abdominal hypertension, and systemic venous congestion. While fluid responsiveness tests clearly identify patients who will not benefit from fluid administration (i.e. those without an increase in cardiac output), the presence of fluid responsiveness does not guarantee that fluid therapy is indicated or even safe. This review calls for more attention to the concept of fluid tolerance, incorporating it into a practical algorithm with systematic venous Doppler ultrasonography assessment to use at the bedside, thereby lowering the risk of detrimental kidney congestion in AKI.
Assuntos
Injúria Renal Aguda , Oligúria , Humanos , Oligúria/terapia , Injúria Renal Aguda/terapia , Hidratação , RimRESUMO
We investigated the role of triterpene barbinervic acid from Eugenia punicifolia dichloromethane extract in vasopressor responses. Renal arteries were cannulated and perfused with Krebs-Hepes solution. Changes in aorta isometric tension were recorded and transferred to a data acquisition system. Cumulative curves were constructed based on the maximum effect of agonists. Barbinervic acid reduced the renal tonus induced by NA in a NO-dependent manner (IC50 = 30 µM). Triterpene (70 µM) also induced rapid and transient relaxation in aorta that had been precontracted with K+ (53.2 ± 0.05%) or phenylephrine (36.7 ± 0.05%). In silico data revealed two possible active sites for interactions between barbinervic acid and NO synthase. Barbinervic acid showed a vasodilator effect and could potentially be used as a template for developing new molecules for the treatment of cardiovascular disease.
Assuntos
Eugenia , Triterpenos , Simulação por Computador , Extratos Vegetais/farmacologia , Folhas de Planta , Triterpenos/farmacologiaRESUMO
ABSTRACT PURPOSE: To analyze the influence of chlorpromazine on renal histology of rats submitted to ischemia and reperfusion injury. METHODS: Sixteen Wistar rats - split in two groups - have been used: control group, receiving 3 mg/kg isotonic saline solution through caudal vein, and, the chlorpromazine group, receiving 3 mg/kg-IV of such medication. The nephrectomy of the left kidney lower third was carried out; immediately, the test-drug was administrated. After 15 minutes of test-drug administration, the renal pedicle was clamped; in 60 minutes of ischemia it was released. After 24 hours of the renal reperfusion, the rats were, once more, anesthetized and submitted to total left nephrectomy, and, afterwards, to euthanasia. Histological findings regarding ischemia have been evaluated and compared between the groups. RESULTS: There was no statistical difference related to inferior renal pole histological analysis. Regarding 60-minute renal ischemia, chlorpromazine has statistically reduced the accrual of leucocytes within the vasa recta renis (p=0.036) and the congestion of peritubular capillaries (p=0.041). When conducting joint analysis of histological patterns, the control group showed a median score of 11 and chlorpromazine group of 5.5 (p=0.036). CONCLUSION: Chlorpromazine significantly reduced the occurrence of secondary damage to ischemia and reperfusion process in the overall histological analysis.
Assuntos
Animais , Masculino , Ratos , Traumatismo por Reperfusão/patologia , Clorpromazina/farmacologia , Precondicionamento Isquêmico/métodos , Rim/irrigação sanguínea , Nefropatias/patologia , Ratos Wistar , Modelos Animais de Doenças , Isquemia/patologia , Rim/patologiaRESUMO
PURPOSE:To analyze the influence of chlorpromazine on renal histology of rats submitted to ischemia and reperfusion injury.METHODS:Sixteen Wistar rats - split in two groups - have been used: control group, receiving 3 mg/kg isotonic saline solution through caudal vein, and, the chlorpromazine group, receiving 3 mg/kg-IV of such medication. The nephrectomy of the left kidney lower third was carried out; immediately, the test-drug was administrated. After 15 minutes of test-drug administration, the renal pedicle was clamped; in 60 minutes of ischemia it was released. After 24 hours of the renal reperfusion, the rats were, once more, anesthetized and submitted to total left nephrectomy, and, afterwards, to euthanasia. Histological findings regarding ischemia have been evaluated and compared between the groups.RESULTS:There was no statistical difference related to inferior renal pole histological analysis. Regarding 60-minute renal ischemia, chlorpromazine has statistically reduced the accrual of leucocytes within the vasa recta renis (p=0.036) and the congestion of peritubular capillaries (p=0.041). When conducting joint analysis of histological patterns, the control group showed a median score of 11 and chlorpromazine group of 5.5 (p=0.036).CONCLUSION:Chlorpromazine significantly reduced the occurrence of secondary damage to ischemia and reperfusion process in the overall histological analysis.(AU)
Assuntos
Animais , Ratos , Clorpromazina/efeitos adversos , Clorpromazina/análise , Traumatismo por Reperfusão/veterinária , Rim/irrigação sanguínea , Rim/lesões , Rim/anatomia & histologia , Nefrectomia/veterinária , Ratos WistarRESUMO
Animal models of renal disease have been used in the study of pathogenesis and the-rapeutic protocols. In this study, doppler ultrasound was used to evaluate dysfunction in the renal vasculature in acute kidney injury in an animal model. Eight male Wistar rats received gentamicin (80 mg/kg) for 10 days. The blood urea and creatinine levels were measured to assess renal function. All doppler ultrasound measurements were performed on both kidneys and a colour map of the renal circulation was generated. Renal function and Doppler ultrasound measurements were performed 10 days before GM treatment and on the 5th and 10th days of the assay. Gentamicin treatment led to increased serum creatinine and blood urea levels at 5 days and 10 days post initial inoculation. A significant reduction in renal artery blood flow was observed after 5 days. However, these levels remained unchanged until the 10th day, demonstrating a lack of correlation with serum creatinine and blood urea levels. Therefore, the assessment of flow blood velocity of renal arteries by doppler ultrasound is not useful for monitoring acute kidney injury in rats.
Modelos animais têm sido utilizados tanto no estudo da patogênese quanto no desenvolvimentode protocolos terapêuticos de doenças renais. No presente trabalho, aultrassonografia com doppler foi usada para avaliar disfunções na vascularização renalem um modelo animal de doença renal aguda. Oito ratos Wistar machos receberamgentamicina (80 mg/kg) durante 10 dias. Os níveis de ureia e creatinina do sangueforam medidos para avaliar a função renal. Todas as medições foram realizadasem ambos os rins, gerando um mapa da circulação renal. As medições da funçãorenal e da ultrassonografia com doppler foram feitas 10 dias antes do tratamentocom gentamicina e no 5° e 10° dia do ensaio. O tratamento levou ao aumento decreatinina sérica e ureia no sangue no 5° e 10° dia após o início da inoculação dagentamicina. Uma redução significativa no fluxo sanguíneo da artéria renal foi observadaapós 5 dias. No entanto, estes níveis permaneceram inalterados até o 10°dia, o que demonstra uma falta de correlação com os níveis de creatinina sérica eureia. Portanto, a avaliação da velocidade do fluxo sanguíneo das artérias renais, porultrassonografia com doppler não é útil para monitorar lesão renal aguda em ratos.
Assuntos
Animais , Ratos , Circulação Renal , Modelos Animais , Ratos , Rim/lesões , Ultrassom , Creatinina , UreiaRESUMO
Animal models of renal disease have been used in the study of pathogenesis and the-rapeutic protocols. In this study, doppler ultrasound was used to evaluate dysfunction in the renal vasculature in acute kidney injury in an animal model. Eight male Wistar rats received gentamicin (80 mg/kg) for 10 days. The blood urea and creatinine levels were measured to assess renal function. All doppler ultrasound measurements were performed on both kidneys and a colour map of the renal circulation was generated. Renal function and Doppler ultrasound measurements were performed 10 days before GM treatment and on the 5th and 10th days of the assay. Gentamicin treatment led to increased serum creatinine and blood urea levels at 5 days and 10 days post initial inoculation. A significant reduction in renal artery blood flow was observed after 5 days. However, these levels remained unchanged until the 10th day, demonstrating a lack of correlation with serum creatinine and blood urea levels. Therefore, the assessment of flow blood velocity of renal arteries by doppler ultrasound is not useful for monitoring acute kidney injury in rats.(AU)
Modelos animais têm sido utilizados tanto no estudo da patogênese quanto no desenvolvimentode protocolos terapêuticos de doenças renais. No presente trabalho, aultrassonografia com doppler foi usada para avaliar disfunções na vascularização renalem um modelo animal de doença renal aguda. Oito ratos Wistar machos receberamgentamicina (80 mg/kg) durante 10 dias. Os níveis de ureia e creatinina do sangueforam medidos para avaliar a função renal. Todas as medições foram realizadasem ambos os rins, gerando um mapa da circulação renal. As medições da funçãorenal e da ultrassonografia com doppler foram feitas 10 dias antes do tratamentocom gentamicina e no 5° e 10° dia do ensaio. O tratamento levou ao aumento decreatinina sérica e ureia no sangue no 5° e 10° dia após o início da inoculação dagentamicina. Uma redução significativa no fluxo sanguíneo da artéria renal foi observadaapós 5 dias. No entanto, estes níveis permaneceram inalterados até o 10°dia, o que demonstra uma falta de correlação com os níveis de creatinina sérica eureia. Portanto, a avaliação da velocidade do fluxo sanguíneo das artérias renais, porultrassonografia com doppler não é útil para monitorar lesão renal aguda em ratos.(AU)
Assuntos
Animais , Ratos , Rim/lesões , Ratos , Ultrassom , Circulação Renal , Modelos Animais , Ureia , CreatininaRESUMO
Background: Sepsis-induced acute kidney injury (AKI) is an early and frequent organ dysfunction, associated with increased mortality. Aim: To evaluate the impact of macrohemodynamic and microcirculatory changes on renal function and histology during an experimental model of intra-abdominal sepsis. Material and Methods: In 18 anaesthetized pigs, catheters were installed to measure hemodynamic parameters in the carotid, right renal and pulmonary arteries. After baseline assessment and stabilization, animals were randomly divided to receive and intra-abdominal infusion of autologous feces or saline. Animals were observed for 18 hours thereafter. Results: In all septic animals, serum lactate levels increased, but only eight developed AKI (66%). These animals had higher creatinine and interleukin-6 levels, lower inulin and para-aminohippurate clearance (decreased glomerular filtration and renal plasma flow), and a negative lactate uptake. Septic animals with AKI had lower values of mean end arterial pressure, renal blood flow and kidney perfusion pressure, with an associated increase in kidney oxygen extraction. No tubular necrosis was observed in kidney histology. Conclusions: The reduction in renal blood flow and renal perfusion pressure were the main mechanisms associated with AKI, but were not associated with necrosis. Probably other mechanisms, such as microcirculatory vasoconstriction and inflammation also contributes to AKI development.
Assuntos
Animais , Feminino , Injúria Renal Aguda , Sepse , Injúria Renal Aguda/sangue , Injúria Renal Aguda/patologia , Injúria Renal Aguda/fisiopatologia , Biomarcadores/sangue , Creatinina/sangue , Modelos Animais de Doenças , Taxa de Filtração Glomerular/fisiologia , Hemodinâmica/fisiologia , /sangue , Microcirculação/fisiologia , Circulação Renal/fisiologia , Sepse/sangue , Sepse/patologia , Sepse/fisiopatologia , Suínos , Fatores de TempoRESUMO
Ectopia renal é uma das mais comuns anormalidades de desenvolvimento renal. Contudo, somente poucos casos de ectopia renal cruzada com fusão têm sido relatados na literatura. Ectopia renal cruzada, geralmente, é uma entidade clinicamente silenciosa, mas algumas vezes complica com infecção urinária de repetição e nefrolitíase e pode ser associada com uma alta incidência de obstrução da junção ureteropélvica, refluxo vesicoureteral e displasia renal multicística. Os autores relatam dois novos casos de ectopia renal cruzada com fusão diagnosticados em um contexto de infecção urinária e nefrolitíase e fazem uma revisão dos mecanismos e características clínicas desta anormalidade. O nefrologista deve estar familiarizado com esta alteração do desenvolvimento renal, uma vez que muitas complicações podem ocorrer durante o seguimento destes pacientes.
Renal ectopia is one of the most common renal abnormalities of kidney development. However, only a few cases of crossed fused renal ectopia have been reported in the literature. Although crossed renal ectopia is usually clinically silent, they is sometime responsible for infection and urinary stones and may be associated with a high incidence of ureteropelvic junction obstruction, vesicoureteral reflux and renal multicystic dysplasia. We report two new cases of crossed renal ectopia with fusion diagnosed in a context of kidney stones and urinary tract infection and review the mechanism and clinical features of this abnormality. We believe that Nephrologist must be familiar with this abnormality of kidney development, as a number of complications may appear during follow-up.
Assuntos
Adulto , Humanos , Masculino , Cálculos Renais/etiologia , Rim/anormalidades , Infecções Urinárias/etiologia , Anormalidades Múltiplas/diagnósticoRESUMO
This study was undertaken in anesthetized dogs to evaluate the relative participation of prostaglandins (PGs) and nitric oxide (NO) in the maintenance of total renal blood flow (TRBF), and renal medullary blood flow (RMBF). It was hypothesized that the inhibition of NO should impair cortical and medullary circulation because of the synthesis of this compound in the endothelial cells of these two territories. In contrast, under normal conditions of perfusion pressure PG synthesis is confined to the renal medulla. Hence PG inhibition should predominantly impair the medullary circulation. The initial administration of 25 µM kg-1 min-1 NG-nitro-L-arginine methyl ester produced a significant 26 percent decrease in TRBF and a concomitant 34 percent fall in RMBF, while the subsequent inhibition of PGs with 5 mg/kg meclofenamate further reduced TRBF by 33 percent and RMBF by 89 percent. In contrast, the initial administration of meclofenamate failed to change TRBF, while decreasing RMBF by 49 percent. The subsequent blockade of NO decreased TRBF by 35 percent without further altering RMBF. These results indicate that initial PG synthesis inhibition predominantly alters the medullary circulation, whereas NO inhibition decreases both cortical and medullary flow. This latter change induced by NO renders cortical and RMBF susceptible to a further decrease by PG inhibition. However, the decrease in medullary circulation produced by NO inhibition is not further enhanced by subsequent PG inhibition.