Catecholamine regulation of local lactate production in vivo in skeletal muscle and adipose tissue: role of -adrenoreceptor subtypes

J Clin Endocrinol Metab. 2008 Jan;93(1):240-6. doi: 10.1210/jc.2007-1313. Epub 2007 Nov 6.

Abstract

Context: The regulation of lactate production in skeletal muscle (SM) and adipose tissue (AT) is not fully elucidated.

Objective: Our objective was to investigate the catecholamine-mediated regulation of lactate production and blood flow in SM and AT in healthy, normal-weight subjects by using microdialysis.

Methods: First, lactate levels in SM and AT were measured during an iv norepinephrine infusion (n = 11). Local blood flow was determined with the 133Xe-clearance technique. Second, muscle lactate was measured during hypoglycemia and endogenous epinephrine stimulation (n = 12). Third, SM was perfused with selective beta(1-3)-adrenoreceptor agonists in situ (n = 8). Local blood flow was measured with the ethanol perfusion technique.

Results: In response to iv norepinephrine, the fractional release of lactate (difference between tissue and arterial lactate) increased by 40% in SM (P = 0.001), whereas remaining unchanged in AT. Blood flow decreased by 40% in SM (P < 0.005) and increased by 50% in AT (P < 0.05). In response to hypoglycemia, epinephrine increased 10-fold, and the fractional release of lactate in SM doubled (P < 0.0001). The blood flow remained unchanged. The beta2-agonist, terbutaline, caused a marked concentration-dependent increase of muscle lactate and blood flow (P < 0.0001). The beta(1)-agonist, dobutamine, induced a discrete increase of muscle lactate (P < 0.0001), and the blood flow remained unchanged. The beta3-agonist, CPG 12177, did not affect muscle lactate or blood flow.

Conclusions: Catecholamines stimulate lactate production in SM, but not in AT. In SM, the beta2-adrenoreceptor is the most important beta-adrenergic receptor subtype in the regulation of lactate production.

MeSH terms

  • Adipose Tissue / blood supply
  • Adipose Tissue / metabolism*
  • Adrenergic beta-Agonists / pharmacology
  • Adult
  • Blood Glucose / metabolism
  • Dobutamine / pharmacology
  • Epinephrine / administration & dosage
  • Epinephrine / metabolism*
  • Female
  • Glucose Clamp Technique
  • Humans
  • Hyperinsulinism / metabolism
  • Lactates / blood
  • Lactates / metabolism*
  • Male
  • Microdialysis
  • Muscle, Skeletal / blood supply
  • Muscle, Skeletal / metabolism*
  • Receptors, Adrenergic, beta / metabolism
  • Terbutaline / pharmacology

Substances

  • Adrenergic beta-Agonists
  • Blood Glucose
  • Lactates
  • Receptors, Adrenergic, beta
  • Dobutamine
  • Terbutaline
  • Epinephrine