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Seasonal biochemical plasticity of a flight muscle in a bat, Murina leucogaster

2000; Elsevier BV; Volume: 126; Issue: 2 Linguagem: Inglês

10.1016/s1095-6433(00)00203-8

1531-4332

Mi Hyun Kim, Kyoungsook Park, Byoung Joo Gwag, Noh‐Pal Jung, Yung Keun Oh, Hyung‐Cheul Shin, Inho Choi,

Mitochondrial Function and Pathology

Cellular and biochemical responses of the pectoral muscle to variation in seasonal activity were studied in the bat, Murina leucogaster ognevi. We collected bats in mid-hibernation (February), end-hibernation (April), and mid-summer (August) to track major activity periods in their annual cycle. Our findings indicated that myofiber cross-sectional area decreased to 68% between mid- and end-hibernation, but returned to the winter level in mid-summer. Total soluble protein and total RNA concentrations were not altered over these sampling periods. Oxidative potential gauged by citrate synthase activity increased 1.47-fold from mid- to end-hibernation and then remained at the similar level in mid-summer. Glycolytic potential gauged by lactate dehydrogenase activity changed little between mid- and end-hibernation but increased 1.42-fold in summer, compared with the winter level. Thus, the myofibers underwent disuse atrophy during hibernation, while enzymatic catalytic function recovered towards the level of mid-summer.