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

• Published in: The journal of clinical endocrinology and metabolism 2008-01, Vol.93 (1), p.240-246
• Main Authors: Qvisth, Veronica, Hagström-Toft, Eva, Enoksson, Staffan, Bolinder, Jan
• Format: Article
• Language: English
• Subjects: 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; Medicin och hälsovetenskap; Microdialysis; Muscle, Skeletal - blood supply; Muscle, Skeletal - metabolism; Receptors, Adrenergic, beta - metabolism; Terbutaline - pharmacology
• ISSN: 0021-972X
• DOI: 10.1210/jc.2007-1313

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