Skin blood flow and nitric oxide during body heating in type 2 diabetes mellitus.
Individuals with type 2 diabetes mellitus (T2DM) often exhibit microvascular dysfunction that may contribute to impaired thermoregulation, but potential mechanisms remain unclear. Our goals were to quantify skin blood flow responses and nitric oxide-mediated vasodilation during body heating in individuals with T2DM compared with nondiabetic control subjects of similar age. We measured skin blood flow (laser-Doppler flowmetry) in conjunction with intradermal microdialysis of N(G)-nitro-l-arginine methyl ester (l-NAME; nitric oxide synthase inhibitor) or vehicle during 45-60 min of whole body heating (WBH) in 10 individuals with T2DM and 14 control subjects. In six individuals from each group, we also measured forearm blood flow (FBF) by venous occlusion plethysmography on the contralateral forearm. FBF responses showed diminished absolute cutaneous vasodilation during WBH in the T2DM group (P(ANOVA) < 0.01; peak FBF in control 13.1 +/- 1.7 vs. T2DM 9.0 +/- 1.6 ml.100 ml(-1).min(-1)). However, the relative contribution of nitric oxide to the cutaneous vasodilator response (expressed as % of maximal cutaneous vascular conductance) was not different between groups (P > 0.05). We conclude that cutaneous vasodilator responses to WBH are decreased in individuals with T2DM, but the contribution of nitric oxide to this smaller vasodilation is similar between T2DM and control individuals. This decrease in cutaneous vasodilation is likely an important contributor to impaired thermoregulation in T2DM.
Sokolnicki
Lynn A
LA
Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55901, USA.
Strom
Nicholas A
NA
Roberts
Shelly K
SK
Kingsley-Berg
Shirley A
SA
Basu
Ananda
A
Charkoudian
Nisha
N
D001783:Blood Flow Velocity; D001831:Body Temperature; D001833:Body Temperature Regulation; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology*; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005260:Female; D005542:Forearm / Q000098:blood supply; D018882:Heat Stress Disorders / Q000378:metabolism / Q000503:physiopathology*; D006358:Hot Temperature; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D017551:Microdialysis; D008875:Middle Aged; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010991:Plethysmography; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D014664:Vasodilation / Q000187:drug effects
D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester