OBJECTIVETo establish an accurate new rat model of hyperammonemia-induced liver injury for use in studies of the molecular mechanisms underlying acute liver failure (ALF).

METHODSTwenty-six Sprague-Dawley rats were administered D-galactosamine (400 mg/kg) and endotoxin (50 mug/kg) via intraperitoneal injection to induce ALF and sacrificed at 12 h post-injection (ALF-12 group, n = 10) or 24 h post-injection (ALF-24 group, n = 16). Ten rats administered physiological saline served as the control group. In addition, 20 rats were given serial oral administrations of 10% NH4Cl solution (10 ml/kg, every 8 hrs) to establish the hyperammonemia-induced liver injury model; an additional 20 rats were prepared in parallel to serve as the ALF control group (n = 10; D-galactosamine at 800 mg/kg every 6 d for 30 days) and the physiological saline control group (n = 10). Serum samples were collected from each mouse and used to detect markers of liver function, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alpha-fetal protein (AFP), and gamma-glutamyltransferase (GGT), as well as blood ammonia (BA) level and prothrombin time activity (PT-A). Affects on liver histology was assessed by hematoxylin and eosin staining of resected liver tissues, and on apoptosis by TUNEL assay and calculating the apoptotic index (AI).

RESULTSALF rats showed elevated levels of ALT (1202.51+/-282.00 U/L), AST (1560.14+/-298.98 U/L), and BA (165.9+/-23.6 mumol/L) as early as 6 hrs after model establishment; these levels peaked at 12 hrs after model establishment (ALT: 774.40+/-207.65 U/L; AST: 967.60+/-121.94 U/L; BA: 143.4+/-18.1 mumol/L; P less than 0.05). No significant variations were detected in the levels of AFP (except for the ALF-24 group) or GGT. Liver tissues of the ALF-12 and ALF-24 groups showed large or diffuse hemorrhagic necroses with sinusoidal congestion or spotty bleeding, as well as increased AI. Hyperammonemia-induced liver injury rats showed elevated levels of ALT and BA as early as 6 hrs after model establishment. Similar to the ALF rats, AFP and GGT were unaffected and AI increased. However, in contrast to the ALF rats, the liver tissues of the hyperammonemia-induced liver injury rats showed no signs of hepatocyte swelling, necrosis, or inflammatory cell invasion.

CONCLUSIONALF rats and hyperammonemia-induced liver injury rats have elevated BA and marked hepatocyte necrosis. Given that reducing the level of ammonemia can improve the animal's biochemistry indexes, it is likely that hyperammonemia plays a role in acute liver injury or ALF consequent to repeated injury. The pathogenic mechanisms of repeated injury may involve promotion of hepatocyte apoptosis in conjunction with inhibition of cellular regeneration.

Animals ; Disease Models, Animal ; Hyperammonemia ; complications ; Liver Failure, Acute ; etiology ; Male ; Rats ; Rats, Sprague-Dawley

Ornithine transcarbamylase deficiency(OTCD)is a most common ornithine cycle (urea cycle) disorder. It is a X-link inherited disorder caused by
Humans ; Hyperammonemia/etiology* ; Liver Transplantation ; Nervous System Diseases/prevention & control* ; Ornithine Carbamoyltransferase Deficiency Disease/therapy*

OBJECTIVETo analyze clinical efficacy and prognosis of liver transplantation in children with hyperammonemia caused by urea cycle disorders.

METHODA retrospective analysis was performed on the occurrence of disease, operation and the follow-up post liver transplantation in 4 patients with urea cycle disorders who underwent liver transplantation during June 2001 to May 2014.

RESULTFour girls were diagnosed with ornithine carbamoyl transferase deficiency by genetic test. They had the clinical onset at the age of 1.5 to 3.0 years. Liver transplantation had been performed at their age of 53.9 months, 40.6 months, 40.3 months and 22.8 months, respectively. The grafts of case 1 and case 2 were from left lateral lobe of liver of cadaveric donor, the graft of case 3 was from left lateral lobe of liver of a living donor, the graft of case 4 was a whole liver of a dead child. The liver function of 4 patients gradually returned to normal, blood ammonia levels were normal and restored the normal diet, 4 children were discharged on postoperative 25-30 days. Regular follow-up was done, the liver function, biochemical features and growth status have been followed up for 162.2 months, 124.2 months, 12.0 months and 4.8 months after liver transplantation, respectively. Now, all the four cases are healthy and growth is normal.

CONCLUSIONLiver transplantation is an important way to the patients with severe hyperammonemia caused by urea cycle disorders. In this study, the patients with ornithine carbamoyl transferase defect got satisfactory long-term outcome after liver transplantation.

Child ; Child, Preschool ; Female ; Humans ; Hyperammonemia ; etiology ; surgery ; Liver ; Liver Function Tests ; Liver Transplantation ; Living Donors ; Ornithine Carbamoyltransferase Deficiency Disease ; complications ; Prognosis ; Retrospective Studies ; Tissue Donors

Ornithine carbamoyltransferase (OTC) deficiency is a urea cycle disorder that causes the accumulation of ammonia, which can lead to encephalopathy. Adults presenting with hyperammonemia who are subsequently diagnosed with urea cycle disorders are rare. Herein, we report a case of a late-onset OTC deficient patient who was successfully treated with arginine, benzoate and hemodialysis. A 59-yr-old man was admitted to our hospital with progressive lethargy and confusion. Although hyperammonemia was suspected as the cause of the patient's mental changes, there was no evidence of chronic liver disease. A plasma amino acid and urine organic acid analysis revealed OTC deficiency. Despite the administration of a lactulose enema, the patient's serum ammonia level increased and he remained confused, leading us to initiate acute hemodialysis. After treatment with arginine, sodium benzoate and hemodialysis, the patient's serum ammonia level stabilized and his mental status returned to normal.
Age of Onset ; Ammonia/blood ; Arginine/therapeutic use ; Citrulline/blood ; Humans ; Hyperammonemia/*etiology ; Male ; Middle Aged ; Ornithine/blood ; Ornithine Carbamoyltransferase Deficiency Disease/complications/*diagnosis/drug therapy ; Pedigree ; Renal Dialysis ; Sodium Benzoate/therapeutic use

Amino Acid Transport Systems, Basic ; genetics ; Brain Diseases ; diagnosis ; etiology ; Child ; DNA Mutational Analysis ; Diet, Protein-Restricted ; Female ; Humans ; Hyperammonemia ; complications ; diagnosis ; diet therapy ; genetics ; Ornithine ; deficiency ; genetics ; Recurrence ; Severity of Illness Index ; Urea Cycle Disorders, Inborn ; complications ; diagnosis ; diet therapy ; genetics