title: The effect of aspirin and various iontophoresis solution vehicles on skin microvascular reactivity.
abstract: The two main objectives of this study were: (1) to examine the effect of aspirin on the endothelial function in healthy subjects and (2) to examine the effect of deionized water and 5% NaCl as iontophoresis solution vehicles. The skin microcirculation was evaluated at the forearm level of healthy subjects. A laser Doppler scanner was employed to measure vasodilation in response to the iontophoresis of 1% acetylcholine (endothelium-dependent) and 1% sodium nitroprusside (endothelium-independent). In the first experiment, nine healthy subjects were given 500 mg aspirin daily for 3 days. The microvascular reactivity was measured at the beginning and the end of the study. In the second experiment, the response to iontophoresis of acetylcholine and sodium nitroprusside as 1% solutions of deionized water was compared to the responses that were achieved after the iontophoresis of deionized water or 5% NaCl solution. After 3 days of aspirin intake, there were no changes in the vasodilatory response to acetylcholine (endothelium-dependent vasodilation) [81 +/- 11 vs 77 +/- 10 (% of increase over baseline at the beginning vs the end of the study, mean +/- SE), P = NS] or sodium nitroprusside (endothelium-independent vasodilation) (69 +/- 8 vs 64 +/- 12, P = NS). There was also a negligible response after the iontophoresis of 5% NaCl (3 +/- 4) and deionized water (6 +/- 4) in anodal mode (the mode employed for the iontophoresis of acetylcholine). In cathodal mode, employed for the iontophoresis of sodium nitroprusside, the response to 5% NaCl was still negligible but a considerable response was found after the iontophoresis of deionized water. In normal healthy subjects, aspirin administration has no effect on forearm skin microvascular reactivity, including both endothelium-dependent and endothelium-independent vasodilation. In addition, a NaCl solution would be preferable to deionized water as the iontophoresis solution vehicle.
authors.affiliation: Clinical Research Center, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Karim
authors.initials: K
authors.lastname: Abou-Elenin
authors.forename: Antonios
authors.initials: A
authors.lastname: Xydakis
authors.forename: Osama
authors.initials: O
authors.lastname: Hamdy
authors.forename: Panayiotis A
authors.initials: PA
authors.lastname: Economides
authors.forename: Edward S
authors.initials: ES
authors.lastname: Horton
authors.forename: Aristidis
authors.initials: A
authors.lastname: Veves
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006801:Humans; D007478:Iontophoresis; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000378:metabolism*; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology; D012867:Skin / Q000098:blood supply* / Q000187:drug effects; D012965:Sodium Chloride / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D013997:Time Factors; D014665:Vasodilator Agents / Q000494:pharmacology; D014867:Water / Q000737:chemistry
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D014665:Vasodilator Agents; D014867:Water; D009599:Nitroprusside; D012965:Sodium Chloride; D000109:Acetylcholine; D001241:Aspirin