Skin vasodilator effect of exogenous urotensin-II in hypertensives not exposed to antihypertensive medication.
To investigate the effect of urotensin-II (U-II) on skin vascular tone in normotensive subjects and in patients with essential arterial hypertension (EHT), forearm skin blood flux and skin blood flowmotion (SBF) response to U-II cathodal iontophoresis was investigated using laser Doppler flowmetry (LDF) and spectral Fourier analysis in 10 young normotensive subjects, before and after intra-dermal injection of the nitric oxide synthetase inhibitor N(G)-monometil-l-arginine (L-NMMA). Forearm skin blood flux response to U-II cathodal iontophoresis was also investigated using LDF in 15 newly diagnosed EHT patients, in 15 long-standing EHT patients and in 15 age- and sex-matched normotensive subjects. Intra-dermal injection of L-NMMA significantly blunted the increase in skin blood flux (from 342.5+/-153.0% to 193.5+/-78.9%, p<0.05) and completely inhibited the increase in spectral amplitude of 0.009-1.6 Hz total-spectrum SBF, as well as of the 0.009-0.02 Hz component, related to endothelial activity, which occurred following U-II iontophoresis in normotensive subjects. A significant increase in skin blood flux compared with baseline was also induced by U-II iontophoresis in newly diagnosed (354+/-195% change from baseline) and long-standing patient (324+/-180% change from baseline), without significant difference with normotensive subjects (400+/-251% change from baseline). These findings demonstrate that: (i) U-II exerts a skin vasodilator effect in normotensive subjects, which is partly endothelial-dependent; (ii) U-II skin vasodilator effect is preserved in newly diagnosed and in long-standing EHT patients.
Department of Internal Medicine, University of Pisa, Italy. mrossi@int.med.unipi.it
Marco
M
Rossi
Armando
A
Magagna
Cinzia
C
Di Maria
Ferdinando
F
Franzoni
Stefano
S
Taddei
Gino
G
Santoro
D000279:Administration, Cutaneous; D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D007271:Injections, Intradermal; D007478:Iontophoresis / Q000379:methods*; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012867:Skin / Q000098:blood supply* / Q000473:pathology; D014579:Urotensins / Q000008:administration & dosage*; D014665:Vasodilator Agents / Q000008:administration & dosage*; D019323:omega-N-Methylarginine / Q000008:administration & dosage
D014579:Urotensins; D014665:Vasodilator Agents; D019323:omega-N-Methylarginine; C029677:urotensin II