Method used to establish a large animal model of drug-induced acute kidney injury

Abstract

Acute kidney injury is a serious health hazard disease due to its complex etiology and lack of effective treatments, resulting in high medical costs and high mortality. At present, a large number of basic research studies on acute kidney injury have been carried out. However, acute kidney injury models established in rodents sometimes do not simulate the course of human disease well. Research in large animal models of acute kidney injury is relatively rare, and methods to build a mature model of acute kidney injury have failed. Because its kidney anatomy and morphology are very similar to those in humans, the mini pig is an ideal animal in which to model kidney disease. Nephrotoxic drug-induced acute kidney injury has a high incidence. In this study, we established models of acute kidney injury induced by two drugs (gentamicin and cisplatin). Finally, the model of cisplatin-induced acute kidney injury was developed successfully, but we found the model of gentamycin-induced acute kidney injury was not reproducible. Compared to other models, these models better represent acute kidney injury caused by antibiotics and chemotherapeutic drugs and provide a basis for the study of new treatments for acute kidney injury in a large animal model.

Keywords: Acute kidney injury; drug-induced model; mini pig.

Figure 1.

Renal function and kidney histology after gentamicin injection. (a–b) Changes in creatinine and urea nitrogen levels in the group treated with 80 mg/kg/day gentamicin. (c–d) Changes in creatinine and urea nitrogen levels in the group treated with 60 mg/kg/day gentamicin. (e–f) Representative photographs of kidney sections from animals given various dosages of gentamicin (periodic acid-Schiff staining; magnification, 200×). (g–h) The black arrows indicate casts, tubular cell degeneration, and necrosis (periodic acid-Schiff staining; magnification, 400×). (A color version of this figure is available in the online journal.)

Figure 2.

Effect of 60 mg/kg/day gentamicin on renal function in mini pigs in three repetitive experiments. (a–b) Changes in the creatinine and urea nitrogen levels of each pig.

Figure 3.

The effects of 2.5 mg/kg and 3.5 mg/kg i.p. cisplatin on renal function and histology in mini pigs. (a–b) Changes in creatinine and urea nitrogen levels after cisplatin injection. (c–f) Representative photographs of kidney sections from animals given 2.5 mg/kg and 3.5 mg/kg cisplatin (periodic acid-Schiff staining; magnification, 200× and 400×). (A color version of this figure is available in the online journal.)

Figure 4.

The effects of 4 mg/kg and 6 mg/kg i.p. cisplatin on renal function and histology in mini pigs. (a–b) Changes in creatinine and urea nitrogen levels after cisplatin injection. (c–f) Representative photographs of kidney sections from animals given 4 mg/kg and 6 mg/kg cisplatin (periodic acid-Schiff staining; magnification, 200× and 400×). (g–h) The abdominal wall of mini pigs after cisplatin or saline injection. (A color version of this figure is available in the online journal.)

Figure 5.

Effect of various doses of i.v. cisplatin on renal function and histology in mini pigs. (a–b) Changes in creatinine and urea nitrogen levels after saline or 3.7–4 mg/kg cisplatin injection. (c–h) Representative photographs of kidney sections from animals given 3.7 mg/kg and 3.8 mg/kg cisplatin (periodic acid-Schiff staining; magnification, 200× and 400×). The black arrows indicate casts, tubular cell degeneration, and necrosis. (i) Histology scores based on standard procedures were significantly different in the groups administered 3.8 mg/kg cisplatin. The quantitative analysis was carried out in 10 random fields per pig. (j) Representative images of TUNEL staining. Scale bar, 50 μm. (k) Quantification of TUNEL-positive cells in the kidney. (A color version of this figure is available in the online journal.)

Figure 6.

Change in histology in mini pigs administered 4 mg/kg i.v. cisplatin. (a–b) Periodic acid-Schiff staining of kidney sections (magnification, 400×). (c–d) Masson staining of kidney sections (magnification, 400×). The black arrows indicate interstitial changes. (e–f) Levels of fibrosis were analyzed by Western blotting. (A color version of this figure is available in the online journal.)

Figure 7.

DNA damage/p53 expression and apoptosis in cisplatin-induced AKI mini pigs. (a) Levels of DNA damage/p53-related proteins were analyzed by Western blotting. (b) Three replicates were used for Western blot quantification. Values are presented as the means ± SDs. *P < 0.05, **P < 0.01, ***P < 0.001 versus the sham group.