Continuous measurement of lactate concentration in skeletal muscle and liver interstitium using a microdialysis...

Interstitial lactate concentration in rat skeletal muscle was continuously measured using a microdialysis method following an acute hemorrhage. For comparison, similar measurements were also performed for liver. Normal lactate levels of skeletal muscle and liver interstitium were 0.58 +/- 0.10 mM and 1.23 +/- 0.04 mM, respectively. After withdrawal of 30% of the estimated total blood volume within 3 min, a constant high blood lactate level was achieved. The lactate concentrations in muscle and liver interstitium also increased to 270 and 210% of the basal levels, respectively, but they did not exceed the blood level. These findings led us to hypothesize that skeletal muscle as well as liver functions as a lactate consumer rather than a producer after acute hemorrhage.