Revisiting the acute kidney injury in Wistar rats experimentally envenomated wity Bothrops jararacussu venom

Intramuscular injection of Bothrops jararaca venom provoked acute kidney injury (AKI): Underpinned by impaired renal filtration, Na+ handling, and tissue damage

Globally, about 2.5 million people are victims of snakebites annually. In Brazil, the most clinically relevant snake is the Bothrops jararaca. The symptoms of envenomation are acute inflammation at the bite site and bleeding disorders. Despite kidney failure being the main cause of death after envenomation, kidney damage is not completely understood, and there are no clinically representative in vivo models. This work aimed to characterize the acute kidney injury (AKI) induced by intramuscular injection (IM) of Bothrops jararaca (Bjc) venom in male Wistar rats. The control group received 0.9% saline solution. Three doses of venom (3.5, 6.0, and 8.0 mg/kg) were administered IM into the posterior region of the right knee. After the injection, the rats were kept in metabolic cages. The following parameters were analyzed after 24 h: the extent of muscle damage and kidney damage (urinary creatinine, proteinuria, plasma creatinine, and renal tissue histology). All rats presented a hemorrhagic lesion at the injection site in a dose-dependent manner. Biochemical parameters indicated kidney damage: plasma creatinine accumulation, decreased glomerular filtration rate, albuminuria and proteinuria, and disturbance in Na+ homeostasis. Histological analyses showed glomerular injury, tissue discontinuity more evident in the cortex and tubular dilatation, and collagen deposition. The decline in renal function and tissue damage indicated the occurrence of AKI. Therefore, a Bjc venom-induced in vivo model of renal injury has been established for future studies.

Renal functional and structural alterations induced by intramuscular injection of Bothrops leucurus venom

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.