Exercise in rats does not alter hypothalamic AMP-activated protein kinase activity.
Recent studies have demonstrated that AMP-activated protein kinase (AMPK) in the hypothalamus is involved in the regulation of food intake. Because exercise is known to influence appetite and cause substrate depletion, it may also influence AMPK in the hypothalamus. Male rats that either rested or ran for 30 or 60 min on a treadmill (22 m/min, 10% slope) were sacrificed immediately after exercise or after 60 min recovery either in the fasted state or after oral gavage with glucose (3g/kg body weight). Exercise decreased muscle and liver glycogen substantially. Hypothalamic total or alpha2-associated AMPK activity and phosphorylation state of the AMPK substrate acetyl-CoA carboxylase were not changed significantly immediately following treadmill running or during fed or fasted recovery. Plasma ghrelin increased (P<0.05) by 40% during exercise whereas the concentration of PYY was unchanged. In recovery, glucose feeding increased plasma glucose and insulin concentrations whereas ghrelin and PYY decreased to (ghrelin) or below (PPY) resting levels. It is concluded that 1h of strenuous exercise in rats does not elicit significant changes in hypothalamic AMPK activity despite an increase in plasma ghrelin. Thus, changes in energy metabolism during or after exercise are likely not coordinated by changes in hypothalamic AMPK activity.
Andersson
Ulrika
U
Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Campus, DuCane Road, London W12 0NN, UK.
Treebak
Jonas T
JT
Nielsen
Jakob N
JN
Smith
Kirsty L
KL
Abbott
Caroline R
CR
Small
Caroline J
CJ
Carling
David
D
Richter
Erik A
EA
D055372:AMP-Activated Protein Kinases; D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D005080:Exercise Test; D005947:Glucose / Q000378:metabolism*; D007031:Hypothalamus / Q000201:enzymology*; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism*; D009752:Nutritional Status / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D009097:Multienzyme Complexes; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D005947:Glucose