Fructose 2,6-bisphosphate and glycolytic flux in skeletal muscle of swimming frog.
Glycolytic flux in skeletal muscle is controlled by 6-phosphofructokinase but how this is achieved is controversial. Brief exercise (swimming) in frogs caused a dramatic increase in the phosphofructokinase activator, fructose 2,6-bisphosphate, in working muscle. The kinetics of phosphofructokinase suggest that in resting muscle, the enzyme is inhibited by ATP plus citrate and that the increase in fructose 2,6-bisphosphate is part of the mechanism to activate phosphofructokinase when exercise begins. When exercise was sustained, fructose 2,6-bisphosphate in muscle was decreased as was the rate of lactate accumulation. Glycolytic flux and the content of fructose 2,6-bisphosphate appear to be closely correlated in working frog muscle in vivo.
Wegener
G
G
Institut für Zoologie, Johannes Gutenberg Universität, Mainz, FRG.
Krause
U
U
Thuy
M
M
D000818:Animals; D001001:Anura / Q000502:physiology*; D004789:Enzyme Activation; D005635:Fructosediphosphates / Q000032:analysis / Q000378:metabolism*; D006019:Glycolysis / Q000502:physiology*; D006598:Hexosediphosphates / Q000378:metabolism*; D007700:Kinetics; D007773:Lactates / Q000032:analysis / Q000378:metabolism; D019344:Lactic Acid; D009043:Motor Activity / Q000502:physiology*; D009132:Muscles / Q000032:analysis / Q000378:metabolism*; D010732:Phosphofructokinase-1 / Q000378:metabolism; D013550:Swimming
D005635:Fructosediphosphates; D006598:Hexosediphosphates; D007773:Lactates; D019344:Lactic Acid; C027652:fructose 2,6-diphosphate; D010732:Phosphofructokinase-1