Local sensory nerve control of skin blood flow during local warming in type 2 diabetes mellitus

• Published in: Journal of applied physiology (1985) 2010-02, Vol.108 (2), p.293-297
• Main Authors: Strom, Nicholas A, Sawyer, Jessica R, Roberts, Shelly K, Kingsley-Berg, Shirley M, Charkoudian, Nisha
• Format: Article
• Language: English
• Subjects: Adult; Aged; Anesthetics, Local - pharmacology; Biological and medical sciences; Blood Glucose - metabolism; Comparative analysis; Diabetes; Diabetes Mellitus, Type 2 - physiopathology; Electrocardiography - drug effects; Female; Fundamental and applied biological sciences. Psychology; Hot Temperature; Humans; Laser-Doppler Flowmetry; Lidocaine - pharmacology; Male; Microdialysis; Middle Aged; Neurons; Regional Blood Flow - drug effects; Regional Blood Flow - physiology; Sensory Receptor Cells - drug effects; Sensory Receptor Cells - physiology; Skin - blood supply; Skin - drug effects; Skin - innervation; Vasodilation - physiology
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.01077.2009

Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota Submitted 22 September 2009 ; accepted in final form 30 November 2009 Cutaneous sensory nerve-mediated vasodilation is an important component of normal microvascular responsiveness to thermal and nonthermal stimuli. Since both neural and microvascular function can be impaired in type 2 diabetes mellitus (T2DM), we tested the hypothesis that local sensory nerve-mediated vasodilation during nonpainful local warming of the skin is less in T2DM compared with healthy controls (C) matched for age and body size. The rapid vasodilation during the first 5 min of this local warming ("initial peak") was previously shown to rely primarily on local sensory nerves. We measured skin blood flow in T2DM and C subjects ( n = 7 in each group) at baseline and during 35 min of local warming of the skin to 42°C at two sites on the ventral forearm. One site was pretreated with 4% lidocaine (LIDO) to block local sensory innervation. During local warming, cutaneous vascular conductance (CVC) during the initial peak was not different between groups, either at the untreated site [T2DM 75 ± 2 vs. C 81 ± 6% of maximum CVC (%maxCVC); P > 0.05] or at the LIDO site (T2DM 63 ± 7 vs. C 64 ± 6%maxCVC; P > 0.05). The difference between untreated and LIDO sites (sensory nerve contribution) was also similar between groups (T2DM 13 ± 5 vs. C 18 ± 5%maxCVC; P > 0.05) and was smaller with LIDO than was previously shown with other local anesthetics. Our results suggest that relatively healthy individuals with T2DM do not exhibit impairments in local sensory nerve vasodilation during thermal stimulation compared with controls of similar age and body size. cutaneous circulation; vasodilation; temperature; metabolic syndrome Address for reprint requests and other correspondence: N. Charkoudian, Dept. of Physiology and Biomedical Engineering, JO 4184W, Mayo Clinic College of Medicine, Rochester, MN 55905 (e-mail: charkoudian.nisha{at}mayo.edu ).