SKELETAL-MUSCLES OF MICE DEFICIENT IN MUSCLE CREATINE-KINASE LACK BURST ACTIVITY

Citation
J. Vandeursen et al., SKELETAL-MUSCLES OF MICE DEFICIENT IN MUSCLE CREATINE-KINASE LACK BURST ACTIVITY, Cell, 74(4), 1993, pp. 621-631
Citations number
64
Categorie Soggetti
Biology,"Cytology & Histology
Journal title
CellACNP
ISSN journal
00928674
Volume
74
Issue
4
Year of publication
1993
Pages
621 - 631
Database
ISI
SICI code
0092-8674(1993)74:4<621:SOMDIM>2.0.ZU;2-W
Abstract
To understand the physiological role of the creatine kinase-phosphocre atine (CK-PCr) system in muscle bioenergetics, a null mutation of the muscle CK (M-CK) gene was introduced into the germline of mice. Mutant mice show no alterations in absolute muscle force, but lack the abili ty to perform burst activity. Their fast-twitch fibers have an increas ed intermyofibrillar mitochondrial volume and an increased glycogenoly tic/glycolytic potential. PCr and ATP levels are normal in resting M-C K-deficient muscles, but rates of high energy phosphate exchange betwe en PCr and ATP are at least 20-fold reduced. Strikingly, PCr levels de cline normally during muscle exercise, suggesting that M-CK-mediated c onversion is not the only route for PCr utilization in active muscle.