title: Increased protein degradation and decreased protein synthesis in skeletal muscle during cancer cachexia.
abstract: The effects of progressive cachexia on protein metabolism in skeletal muscle has been investigated in mice bearing the MAC16 adenocarcinoma which produces cachexia with tumour burdens of < 1% of the host weight. Weight loss was accompanied by loss of whole body nitrogen in proportion to the overall loss of body mass. Using L-[4-3H]phenylalanine to label proteins in gastrocnemius muscle, a significant depression (60%) in protein synthesis occurred in animals with a weight loss between 15 and 30% accompanied by an increase in protein degradation, which increased with increasing weight loss between 15 and 30%. Muscle degradation in vitro could be achieved by serum from cachectic animals, which appeared to contain a proteolysis-inducing factor. These results suggest that the increased degradation of skeletal muscle seen in this model of cachexia may be due to a circulating proteolysis-inducing factor.
authors: Cancer Research Campaign Experimental Chemotherapy Group, Pharmaceutical Sciences Institute, Aston University, Birmingham, UK.
authors: K L
authors: KL
authors: Smith
authors: M J
authors: MJ
authors: Tisdale
mesh_terms: D000818:Animals; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D002100:Cachexia / Q000209:etiology / Q000378:metabolism*; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D009124:Muscle Proteins / Q000096:biosynthesis / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000150:complications / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism
chemical_list: D009124:Muscle Proteins; D009584:Nitrogen