Seasonal biochemical plasticity of a flight muscle in a bat, Murina leucogaster.
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.
Department of Life Science, College of Liberal Arts and Sciences, Yonsei University, 234 Maeji-Ri, Heungup-Myon, Wonju, 222-710, Kangwon-Do, South Korea.
M H
MH
Kim
K
K
Park
B J
BJ
Gwag
N P
NP
Jung
Y K
YK
Oh
H C
HC
Shin
I H
IH
Choi
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D012621:Seasons
D009124:Muscle Proteins; D007770:L-Lactate Dehydrogenase; D008058:Dihydrolipoamide Dehydrogenase; D000251:Adenosine Triphosphatases