Differences between glycogen biogenesis in fast- and slow-twitch rabbit muscle.
Skeletal muscle glycogen is an essential energy substrate for muscular activity. The biochemical properties of the enzymes involved in de novo synthesis of glycogen were analysed in two types of rabbit skeletal muscle fiber (fast- and slow-twitch). Glycogen concentration was higher in fast-twitch muscle than in slow-twitch muscle, but the latter contained many more small intermediate-acceptor molecules that could act as glycogen synthase substrates. The enzymes involved in de novo synthesis of glycogen in fast-twitch muscle were strongly stimulated by Glc-6-P, but those in slow-twitch muscle were not.
Cussó
R
R
Unitat de Bioquimica, Facultat de Medicina, Institut de Biomedicina August Pi i Sunyer (IDIBAPS), Universitat de Barcelona c/ Casanova 153, Spain. cusso@medicina.ub.es
Lerner
L R
LR
Cadefau
J
J
Gil
M
M
Prats
C
C
Gasparotto
M
M
Krisman
C R
CR
D000818:Animals; D019298:Glucose-6-Phosphate / Q000494:pharmacology; D006003:Glycogen / Q000096:biosynthesis* / Q000172:deficiency; D066298:In Vitro Techniques; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D011817:Rabbits
D019298:Glucose-6-Phosphate; D006003:Glycogen