Skin glucose metabolism and microvascular blood flow during local insulin delivery and after an oral glucose load.
Insulin causes capillary recruitment in muscle and adipose tissue, but the metabolic and microvascular effects of insulin in the skin have not been studied in detail. The aim of this study was to measure glucose metabolism and microvascular blood flow in the skin during local insulin delivery and after an oral glucose load.



Microdialysis catheters were inserted intracutanously in human subjects. In eight subjects two microdialysis catheters were inserted, one perfused with insulin and one with control solution. First the local effects of insulin was studied, followed by a systemic provocation by an oral glucose load. Additionally, as control experiment, six subjects did not recieve local delivery of insulin or the oral glucose load. During microdialysis the local blood flow was measured by urea clearance and by laser speckle contrast imaging (LSCI).



Within 15 minutes of local insulin delivery, microvascular blood flow in the skin increased (urea clearance: P=.047, LSCI: P=.002) paralleled by increases in pyruvate (P=.01) and lactate (P=.04), indicating an increase in glucose uptake. An oral glucose load increased urea clearance from the catheters, indicating an increase in skin perfusion, although no perfusion changes were detected with LSCI. The concentration of glucose, pyruvate and lactate increased in the skin after the oral glucose load.



Insulin has metabolic and vasodilatory effects in the skin both when given locally and after systemic delivery through an oral glucose load.
Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden. fredrik.iredahl@liu.se.
Fredrik
F
Iredahl
Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Alexandra
A
Högstedt
Department of Dermatology and Venerology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Joakim
J
Henricson
Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.|Department of Hand Surgery, Plastic Surgery, and Burns, Linköping University, Linköping, Sweden.
Folke
F
Sjöberg
Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.|Department of Radiation Physics, Linköping University, Linköping, Sweden.
Erik
E
Tesselaar
Department of Hand Surgery, Plastic Surgery, and Burns, Linköping University, Linköping, Sweden.
Simon
S
Farnebo
D000328:Adult; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D017551:Microdialysis; D019289:Pyruvic Acid / Q000097:blood; D012039:Regional Blood Flow / Q000187:drug effects*; D012867:Skin / Q000098:blood supply* / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects; D055815:Young Adult
D007328:Insulin; D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose
insulin; metabolism; microcirculation; microdialysis; skin