Preservation of pressure-induced cutaneous vasodilation by limiting oxidative stress in short-term diabetic mice.
OBJECTIVE
Pressure-induced vasodilation (PIV) allows skin blood flow to increase in response to locally applied pressure and may be protective against pressure ulcers. We previously showed that PIV was absent in 1-week diabetic mice exhibiting no neuropathy. Our aim was to determine whether the diabetes-induced PIV alteration could be prevented.


RESULTS
Diabetic mice received no treatment or a daily treatment with either sorbinil, alagebrium or alpha-lipoic acid (LPA) for 1 week. Laser Doppler flowmetry was used to evaluate PIV as well as endothelium-dependent vasodilation following iontophoretic delivery of acetylcholine (ACh). The effect of each treatment on oxidative stress was examined by plasma 8-isoprostane assay. LPA was the sole treatment to prevent both PIV and ACh vasodilation alterations, with a significant reduction of oxidative stress in diabetic mice. Both PIV and ACh-vasodilation were abolished in LPA-treated diabetic mice following injection of Nomega-nitro-L-arginine (p<0.05). In contrast, alagebrium and sorbinil prevented neither diabetes-induced PIV abolition nor endothelial alteration.


CONCLUSIONS
LPA treatment significantly reduced the oxidative stress and was able to preserve endothelial nitric oxide availability in the cutaneous microcirculation and then to preserve the PIV response in diabetic mice. LPA treatment could play a key role in limiting the risk of pressure-induced cutaneous ulcer during diabetes.
Demiot
Claire
C
Laboratory of physiology, UMR CNRS 6188, Medical school, 49045 Angers cedex, France.
Fromy
Bérengère
B
Saumet
Jean Louis
JL
Sigaudo-Roussel
Dominique
D
D000109:Acetylcholine / Q000494:pharmacology; D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors; D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D003920:Diabetes Mellitus / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D048289:Imidazolidines / Q000494:pharmacology; D017078:Laser-Doppler Flowmetry; D008297:Male; D051379:Mice; D008833:Microcirculation; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D018384:Oxidative Stress; D011312:Pressure; D003668:Pressure Ulcer / Q000097:blood / Q000378:metabolism / Q000517:prevention & control*; D012039:Regional Blood Flow / Q000187:drug effects; D012867:Skin / Q000098:blood supply*; D008063:Thioctic Acid / Q000627:therapeutic use*; D014664:Vasodilation; D014665:Vasodilator Agents / Q000494:pharmacology
D000975:Antioxidants; D015415:Biomarkers; D048289:Imidazolidines; D014665:Vasodilator Agents; D019335:Nitroarginine; C075750:8-epi-prostaglandin F2alpha; D008063:Thioctic Acid; D015237:Dinoprost; D000449:Aldehyde Reductase; D019001:Nitric Oxide Synthase; C026411:sorbinil; D000109:Acetylcholine