Muscle dysfunction during exercise of a single skeletal muscle in rats with congestive heart failure is not associated with reduced muscle blood supply.
OBJECTIVE
Inadequate muscle blood flow is a possible explanation for reduced fatigue resistance in patients with congestive heart failure (CHF).


METHODS
In rats with post-infarction CHF we electrically stimulated the soleus muscle (SOL) in situ with intact blood supply. Contractile properties, blood flow, high-energy phosphates and metabolites were measured during 30 min of intermittent stimulation, and in addition capillarization of SOL was recorded.


RESULTS
During stimulation, SOL contracted more slowly in rats with CHF compared with sham-operated rats. However, the blood flow in SOL was unaltered and capillary density was maintained in CHF rats. Further, the content of ATP, ADP, AMP, NAD, CrP, P(i) and lactate in SOL was not different between the groups.


CONCLUSIONS
The cause of contractile dysfunction in a single exercising skeletal muscle in rats with CHF cannot be explained simply by reduced blood supply. In addition, absence of changes in high-energy phosphates and metabolites indicate that the oxidative metabolism of SOL is intact in rats with CHF.
Schiøtz Thorud
H-M
HM
Institute for Experimental Medical Research, Ullevaal University Hospital, and Centre for Heart Failure Research, University of Oslo, Oslo, Norway.
Lunde
P K
PK
Nicolaysen
G
G
Nicolaysen
A
A
Helge
J W
JW
Nilsson
G E
GE
Sejersted
O M
OM
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D002097:C-Reactive Protein / Q000032:analysis; D002196:Capillaries / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology; D006333:Heart Failure / Q000503:physiopathology*; D006614:Hindlimb; D007773:Lactates / Q000032:analysis; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology*; D009243:NAD / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D010805:Physical Conditioning, Animal / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology
D007773:Lactates; D010710:Phosphates; D009243:NAD; D002097:C-Reactive Protein