Forskning ved Københavns Universitet - Københavns Universitet

Forside

Endotoxemia stimulates skeletal muscle Na+-K+-ATPase and raises blood lactate under aerobic conditions in humans

Publikation: Forskning - peer reviewTidsskriftartikel

Henning Bundgaard, Keld Per Kjeldsen, Karen Suarez Krabbe, Gerrit van Hall, Lene Simonsen, Jesper Qvist, Christian Muff Hansen, Kirsten Møller, Lise Fonsmark, Per Lav Madsen, Bente Klarlund Pedersen

We assessed the hypothesis that the epinephrine surge present during sepsis accelerates aerobic glycolysis and lactate production by increasing activity of skeletal muscle Na(+)-K(+)-ATPase. Healthy volunteers received an intravenous bolus of endotoxin or placebo in a randomized order on two different days. Endotoxemia induced a response resembling sepsis. Endotoxemia increased plasma epinephrine to a maximum at t = 2 h of 0.7 +/- 0.1 vs. 0.3 +/- 0.1 nmol/l (P < 0.05, n = 6-7). Endotoxemia reduced plasma K(+) reaching a nadir at t = 5 h of 3.3 +/- 0.1 vs. 3.8 +/- 0.1 mmol/l (P < 0.01, n = 6-7), followed by an increase to placebo level at t = 7-8 h. During the declining plasma K(+), a relative accumulation of K(+) was seen reaching a maximum at t = 6 h of 8.7 +/- 3.8 mmol/leg (P < 0.05). Plasma lactate increased to a maximum at t = 1 h of 2.5 +/- 0.5 vs. 0.9 +/- 0.1 mmol/l (P < 0.05, n = 8) in association with increased release of lactate from the legs. These changes were not associated with hypoperfusion or hypoxia. During the first 24 h after endotoxin infusion, renal K(+) excretion was 27 +/- 7 mmol, i.e., 58% higher than after placebo. Combination of the well-known stimulatory effect of catecholamines on skeletal muscle Na(+)-K(+)-ATPase activity, with the present confirmation of an expected Na(+)-K(+)- ATPase-induced decline in plasma K(+), suggests that the increased lactate release was due to increased Na(+)-K(+)-ATPase activity, supporting our hypothesis. Thus increased lactate levels in acutely and severely ill patients should not be managed only from the point of view that it reflects hypoxia.
OriginalsprogEngelsk
TidsskriftAmerican Journal of Physiology: Heart and Circulatory Physiology
Vol/bind284
Tidsskriftsnummer3
Sider (fra-til)H1028-H1034
Antal sider7
ISSN0363-6135
StatusUdgivet - 31 dec. 2003

ID: 162989860