A Macaca mulatta model of fulminant hepatic failure

Abstract

Aim: To establish an appropriate primate model of fulminant hepatic failure (FHF).

Methods: We have, for the first time, established a large animal model of FHF in Macaca mulatta by intraperitoneal infusion of amatoxin and endotoxin. Clinical features, biochemical indexes, histopathology and iconography were examined to dynamically investigate the progress and outcome of the animal model.

Results: Our results showed that the enzymes and serum bilirubin were markedly increased and the enzyme-bilirubin segregation emerged 36 h after toxin administration. Coagulation activity was significantly decreased. Gradually deteriorated parenchymal abnormality was detected by magnetic resonance imaging (MRI) and ultrasonography at 48 h. The liver biopsy showed marked hepatocyte steatosis and massive parenchymal necrosis at 36 h and 49 h, respectively. The autopsy showed typical yellow atrophy of the liver. Hepatic encephalopathy of the models was also confirmed by hepatic coma, MRI and pathological changes of cerebral edema. The lethal effects of the extrahepatic organ dysfunction were ruled out by their biochemical indices, imaging and histopathology.

Conclusion: We have established an appropriate large primate model of FHF, which is closely similar to clinic cases, and can be used for investigation of the mechanism of FHF and for evaluation of potential medical therapies.

Keywords: Biochemistry; Fulminant hepatic failure; Imaging; Macaca mulatta; Pathology.

Figure 1

Blood biochemical parameters of the Macaca mulatta model of fulminant hepatic failure. The abscissa and ordinate represent measured time and value, respectively. ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; TBIL: Total bilirubin; DBIL: Direct bilirubin; IBIL: Indirect bilirubin; PT: Prothrombin time; APTT: Activated partial thromboplastin time; CK: Creatine kinase; LDH: Lactate dehydrogenase; CRE: Creatinine; UA: Uric acid; GLU: Glucose; FHF: Fulminant hepatic failure. ¹Represents values > 300 s, which exceeded the range of the equipment, so we did not obtain an exact measurement.

Figure 2

Magnetic resonance imaging of the liver and brain of Macaca mulatta model at different times. T2WI: T2-weighted imaging; T1WI: T1-weighted imaging.

Figure 3

Liver sonogram of the Macaca mulatta model at different times. Arrows show a slightly enhanced echo and lower perfusion of SonoVue at 48 h.

Figure 4

Histopathological changes of the liver. A: Tissue from needle biopsy at 12 h. Changes in organizational structure and cell morphology were not obvious [hematoxylin and eosin (H and E) stain, × 200]; B: Tissue from needle biopsy at 36 h. Vacuoles appeared in the hepatocellular cytoplasm (H and E stain, × 200); C, D: Tissue from necropsy after death at 70 h. Hepatocellular necrosis was distributed in the portal area (C) and central area (D) (H and E stain, × 200). Massive necrosis caused almost all of the hepatocytes to be lost, and only the support structure remained; E: Frozen tissue from needle biopsy at 36 h. The extensive reddish-orange color suggested serious fatty degeneration (oil red O stain, × 100); F: Frozen tissue from needle biopsy at 36 h. In the borderline between necrosis and steatosis, the reddish-orange color was obvious (oil red O stain, × 200); G, H: Comparison of pathological changes of fulminant hepatic failure in humans induced by viral hepatitis (G) and a Macaca mulatta model induced by α-amanitin and lipopolysaccharide (H) (H and E stain, × 200); I: Normal liver of Macaca mulatta for comparison; J: The surface view of the experimental liver on necropsy appeared red and yellow; K: The cut surface view of the experimental liver was uniformly yellow.

Figure 5

Other main organs on necropsy. A: The brain with cerebral edema; B: Mesenteric lymph nodes enlarged and beaded; Hyperemia of the kidney (C), spleen (D), heart (E), and pancreas (F) without obvious gross lesions.

Figure 6

Histopathological changes of other organs. A: Ectasia and hyperemia of capillaries in the renal glomerulus [hematoxylin and eosin (H and E) stain, × 200]; B: Widespread hyperemia of capillaries in the renal stroma and cellular swelling in the tubular epithelial cells (H and E stain, × 100); C: Weak staining in the superficial layer of the brain suggest cerebral edema (H and E stain, × 100); D: Wave-like changes in the myocardium (H and E stain, × 200); E: Hyperemia of capillaries in the stroma and hyaline changes in the arterioles of the lung (H and E stain, × 200); F: Hyaline changes in the central artery of the spleen (H and E stain, × 200); G: Widespread reduction in lymphocytes and hemorrhage in the mesenteric lymph nodes (H and E stain, × 50); H: Hemorrhage and histiocyte proliferation in the mesenteric lymph nodes. Hyaline change appeared in the vessel wall of lymphoid follicles (H and E stain, × 200).