Absolute concentrations of glycerol and lactate in human skeletal muscle, adipose tissue and blood. Hagstrsm-Toft, Eva, Staffan Enoksson, Erik Moberg, Jan Bolinder, and Peter Arner . Department of Medicine and the Research Center and Department of Vascular Surgery, Huddinge University Hospital, Karolinska Institute, S-141 86 Huddinge, Sweden
APStracts 4:0115E, 1997.
The absolute concentrations of glycerol and lactate were studied with microdialysis of adipose tissue and skeletal muscle in normal-weight subjects. The basal interstitial glycerol concentration was 232+/-33, 96+/-8 and 59+/-6 [mu]mol/l in fat, muscle and arterialized plasma, respectively (p=0.0002). This relation was maintained during both euglycemic hyperinsulinemia, when glycerol decreased in all three compartments and hypoglycemia, when glycerol first decreased, then increased in fat, muscle and blood (p=0.0001 for both). Basal interstitial lactate concentrations were similar in adipose tissue (1.1+/-0.2 mmol/l) and skeletal muscle (1.9+/-0.4 mmol/l) and higher than in arterialized blood (0.6+/-0.1 mmol/l, p=0.002). During hyperinsulinemia and hypoglycemia, lactate increased (p=0.0001) and the tissue/blood relation was maintained (p=0.04). In conclusion, adipose tissue and skeletal muscle mobilize glycerol and lactate at rest. Glycerol and lactate production are influenced by hyperinsulinemia and hypoglycemia in both tissues. Adipose tissue appears to be the major site of glycerol production, whereas skeletal muscle and fat may be equally important for lactate production.

Received 24 December 1996; accepted in final form 8 May 1997.
APS Manuscript Number E625-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 11 June 1997