Evaluation of a combined laser Doppler flowmetry and iontophoresis technique for the assessment of equine cutaneous microvascular function.
A combined laser Doppler flowmetry and iontophoresis (LDFI) technique, used routinely to assess human microvascular function, was evaluated as a noninvasive technique for assessment of equine microvascular function, to facilitate the study of diseases such as laminitis. Baseline and vasoactive agonist-induced (acetylcholine and nitroprusside) microvascular flux was quantified at 2 sites (on the dorsal pastern adjacent to the coronary band and over the gluteals) in 6 clinically normal horses on 5 or 6 separate occasions under standardised conditions. Both agonists significantly increased microvascular flux. Skin pigmentation significantly attenuated the baseline flux, but not the magnitude of the agonist-mediated vasodilatory response. While LDFI was simple to perform, its value as a clinical and research tool for assessing the equine cutaneous microcirculation is limited by its poor reliability, as indicated by the marked intra- and intersubject variability in baseline and agonist-mediated microvascular flux.
McGorum
B C
BC
Easter Bush Veterinary Centre, University of Edinburgh, Roslin, Midlothian, UK.
Milne
A J
AJ
Tremaine
W H
WH
Sturgeon
B P R
BP
McLaren
M
M
Khan
F
F
D000109:Acetylcholine; D000279:Administration, Cutaneous; D000818:Animals; D004730:Endothelium, Vascular / Q000502:physiology; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis; D006736:Horses / Q000502:physiology*; D007478:Iontophoresis / Q000379:methods / Q000662:veterinary*; D017078:Laser-Doppler Flowmetry / Q000379:methods / Q000662:veterinary*; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D009599:Nitroprusside; D012039:Regional Blood Flow / Q000502:physiology; D012867:Skin / Q000098:blood supply*; D013268:Stimulation, Chemical; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine