Muscle wasting and branched‐chain amino acid, alpha‐ketoglutarate, and ATP depletion in a rat model of liver cirrhosis

• Published in: International journal of experimental pathology Vol. 99; no. 6; pp. 274 - 281
• Main Authors: Holeček, Milan, Vodeničarovová, Melita
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.12.2018; John Wiley and Sons Inc
• Subjects: Adenosine Triphosphate - deficiency; Alanine; Amino acids; Amino Acids, Branched-Chain - metabolism; Ammonia; ammonia detoxification; Animals; Biomarkers; Blood levels; Blood plasma; Body Weight - drug effects; Cachexia; Carbon tetrachloride; Carbon Tetrachloride - pharmacology; Chain branching; Chains; Chymotrypsin; Cirrhosis; Depletion; Detoxification; Disease Models, Animal; Eating - drug effects; Glutamine; Ketoglutaric acid; Ketoglutaric Acids - metabolism; Liver; Liver cirrhosis; Liver Cirrhosis - chemically induced; Liver Cirrhosis - complications; Liver Cirrhosis - metabolism; Liver Cirrhosis - pathology; Male; Metabolism; Mitochondria; Muscle Proteins - metabolism; Muscle, Skeletal - metabolism; Muscle, Skeletal - pathology; Muscles; Organ Size - drug effects; Original; Pathogenesis; Phenylalanine; Proteins; Proteolysis; Rats, Wistar; Rodents; Sarcopenia - etiology; Sarcopenia - metabolism; Sarcopenia - pathology; Skeletal muscle; Soleus muscle; Tyrosine; ammonia detoxification; glutamine; liver cirrhosis; cachexia
• ISSN: 0959-9673; 1365-2613; 1365-2613
• DOI: 10.1111/iep.12299

Summary The aim of the study was to examine whether a rat model of liver cirrhosis induced by carbon tetrachloride (CCl4) is a suitable model of muscle wasting and alterations in amino acid metabolism in cirrhotic humans. Rats were treated by intragastric gavage of CCl4 or vehicle for 45 days. Blood plasma and different muscle types—tibialis anterior (mostly white fibres), soleus (red muscle) and extensor digitorum longus (white muscle) ‐ were analysed at the end of the study. Characteristic biomarkers of impaired hepatic function were found in the plasma of cirrhotic animals. The weights and protein contents of all muscles of CCl4‐treated animals were lower when compared with controls. Increased concentrations of glutamine (GLN) and aromatic amino acids (phenylalanine and tyrosine) and decreased concentrations of branched‐chain amino acids (BCAA), glutamate (GLU), alanine and aspartate were found in plasma and muscles. In the soleus muscle, GLN increased more and GLU and BCAA decreased less than in the extensor digitorum and tibialis muscles. Increased chymotrypsin‐like activity (indicating enhanced proteolysis) and decreased α‐ketoglutarate and ATP levels were found in muscles of cirrhotic animals. ATP concentration also decreased in blood plasma. It is concluded that a rat model of CCl4‐induced cirrhosis is a valid model for the investigation of hepatic cachexia that exhibits alterations in line with a theory of role of ammonia in pathogenesis of BCAA depletion, citric cycle and mitochondria dysfunction, and muscle wasting in cirrhotic subjects. The findings indicate more effective ammonia detoxification to GLN in red than in white muscles.