Escherichia coli endotoxin reduces cytochrome aa3 redox status in pig skeletal muscle.
OBJECTIVE
To assess the effect of endotoxin on cytochrome aa3 (Caa3) redox status in a controlled blood flow preparation of pig isolated hindlimb, at a constant oxygen delivery (Do2limb) (constant flow period) and during progressive ischemia (decreasing flow period).


METHODS
Randomized, controlled experimental study.


METHODS
University hospital experimental laboratory.


METHODS
Ten piglets.


METHODS
Hindlimb blood flow was restricted to the femoral vessels. The arterial femoral blood flow coming from the carotid artery was controlled by a roller occlusive pump. The femoral venous blood flow was returned to the jugular vein. During the first 100 mins, the hindlimb blood flow was maintained at a normal level and then decreased stepwise. Animals were randomized to receive 150 microg/kg endotoxin lipopolysaccharide (LPS; n = 5) or saline (control; n = 5).


RESULTS
Hindlimb muscle Caa3 redox status was monitored by near-infrared spectroscopy. Hindlimb Do2limb and oxygen consumption (Vo2limb) were calculated. In the LPS group, a rapid reduction of Caa3 redox status was observed after LPS administration, whereas the hindlimb blood flow remained normal with no change in Do2limb and Vo2limb. A progressive simultaneous decrease in Do2limb and Vo2limb was observed during the decreasing flow period with no further reduction in Caa3 redox status. In the control group, no change was observed in Caa3, Do2limb, or Vo2limb during the constant flow period. During the decreasing flow period, Caa3 redox status was reduced as Do2limb and Vo2limb decreased.


CONCLUSIONS
Our results suggest that endotoxin may induce a reduction of Caa3 redox status independently of Do2 and Vo2.
Forget
A P
AP
Department of Anesthesiology, CHRU de Lille, France.
Mangalaboyi
J
J
Mordon
S
S
Guery
B
B
Vallet
B
B
Fourrier
F
F
Chopin
C
C
D000818:Animals; D004195:Disease Models, Animal; D003576:Electron Transport Complex IV / Q000276:immunology / Q000378:metabolism*; D004926:Escherichia coli; D005260:Female; D006439:Hemodynamics; D006614:Hindlimb; D007249:Inflammation; D016014:Linear Models; D008070:Lipopolysaccharides / Q000009:adverse effects*; D008991:Monitoring, Physiologic; D009102:Multiple Organ Failure / Q000209:etiology* / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000201:enzymology* / Q000276:immunology; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011897:Random Allocation; D012772:Shock, Septic / Q000150:complications* / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D019265:Spectroscopy, Near-Infrared; D013552:Swine
D008070:Lipopolysaccharides; D003576:Electron Transport Complex IV