Hibernating black bears (Ursus americanus) experience skeletal muscle protein balance during winter anorexia.

摘要: Black bears spend four to seven months every winter confined their den and anorexic. Despite potential for skeletal muscle atrophy protein loss, appear retain integrity throughout dormancy. Other authors have suggested that are capable of net anabolism during this time. The present study was performed test hypothesis by directly measuring metabolism the summer, as well early late hibernation periods. Muscle biopsies were taken from vastus lateralis six free-ranging in others again winter. Protein synthesis breakdown measured on using (14)C-phenylalanine a tracer. protein, nitrogen, nucleic acid content, nitrogen stable isotope enrichment, also measured. greater than summer bears, suggesting they accumulate periods seasonal food availability. both lower compared but equal denning, indicating balance hibernation. acid, enrichment measurements support conclusion.