RESUMO
Acute kidney injury (AKI) is the main cause of death from Bothrops snakebite. Although many studies have investigated the nephrotoxicity induced by other Bothrops species, no study has assessed the renal alterations induced by intramuscular (i.m.) injection of Bothrops leucurus venom. In this study, we evaluated the nephrotoxicity induced by B. leucurus venom by analyzing renal function and histology. Wistar rats were submitted to i. m. injection of B. leucurus venom or saline and divided into two groups: Control group (C), rats submitted to i. m. injections of saline, and B. leucurus group (Bl), rats submitted to i. m. injections of B. leucurus venom (1 mg/kg). After venom or saline injection, serum and urine were collected to measure creatinine, albumin, sodium, and potassium levels. The glomerular filtration rate (GFR), urinary flow urinary, creatinine/serum creatinine ratio, and albuminuria-urinary creatinine ratio were determined. All rats were euthanized 72 h following the injections, and the kidneys were removed for histology and immunohistochemical studies. B. leucurus experimental envenoming was accompanied by an increase of 236% in serum creatine kinase activity in the Bl group. The weights of the right and left kidneys were, respectively, 26 and 22% higher in rats of the Bl group than in control rats. Regarding renal function, the Bl group showed a decrease of 37% in GFR compared to control group. The rats of the Bl group also presented increased cortical (8.20 ± 1.35) and medullar (6.17 ± 2.00) tubulointerstitial lesion area when compared to control group (0.02 ± 0.00) (1.20 ± 0.73), respectively. The number of macrophages was also higher in the renal cortex (6.66 ± 0.06) and medulla (1.22 ± 0.10) of rats from the Bl group when compared to control rats (1.04 ± 0.55), (0.65 ± 0.10), respectively. Our results indicate that B. leucurus venom promoted significant histological and functional renal alterations following intramuscular inoculation, which simulates the majority of snakebites observed in the clinical practice.
RESUMO
Objective: This study aimed to evaluate the effects of ovariectomy on glycerol-induced renal changes in rats. Methods: Twenty-four female Wistar rats were submitted to ovariectomized (OVX) or sham surgery. One week after surgery, the animals received an intramuscular injection (8ml/kg) of 50% glycerol or saline (0.15 M) solution. These animals were divided into the following groups (n=6 per group): Sham, sham-operated female rats injected with saline; OVX, ovariectomized female rats injected with saline; Sham+Gly, sham-operated female rats injected with glycerol; OVX+Gly, ovariectomized female rats injected with glycerol. All rats were euthanized 3 days after the injections and the kidneys were removed for histological and immunohistochemical studies. Blood and urine samples were also collected for renal function studies. Results: The OVX+Gly group presented higher creatinine serum levels, as well as greater fractional excretion of sodium and urinary flow than the Sham+Gly group. Histological lesions and tubulointerstitial staining for macrophages, nuclear factor-kappa B, and nitrotyrosine were more pronounced in the renal cortex of the OVX+Gly group compared to the Sham+Gly group. Conclusion: We conclude that ovariectomy aggravated changes in renal function and structure in glycerol-induced acute kidney injury by the intensification of the proinflammatory tissue response.
Objetivo: Avaliar os efeitos da ovariectomia nas alterações renais induzidas pelo glicerol em ratas. Métodos: Vinte e quatro ratas Wistar foram submetidas à ovariectomia (OVX) ou cirurgia sham (intervenção falsa). Uma semana após a cirurgia, os animais receberam injeção intramuscular (8ml/kg) de glicerol a 50% ou solução salina (0,15 M). As ratas foram divididas nos seguintes grupos (n=6 por grupo): Sham, fêmeas sham-operadas e injetadas com solução salina; OVX, fêmeas ovariectomizadas e injetadas com solução salina; Sham+Gly, fêmeas sham-operadas e injetados com glicerol; OVX+Gly, fêmeas ovariectomizadas e injetadas com glicerol. Todas as ratas foram eutanasiadas 3 dias após as injeções e os rins foram removidos para estudos histológicos e imuno-histoquímicos. Amostras de sangue e urina também foram coletadas para estudos de função renal. Resultados: O grupo OVX+Gly apresentou maiores níveis séricos de creatinina, assim como maiores fração de excreção de sódio e fluxo urinário do que o grupo Sham+Gly. As lesões histológicas e imunomarcação tubulointersticial para macrófagos, fator nuclear-kappa B e nitrotirosina foram mais pronunciadas no córtex renal do grupo OVX+Gly em comparação ao grupo Sham+Gly. Conclusão: Concluímos que a ovariectomia agravou as alterações na função e estrutura renal, na lesão renal aguda induzida por glicerol, pela intensificação da resposta tecidual pró-inflamatória.
