Effect of isoflurane on skin-pressure-induced vasodilation.
Since general anesthesia has been shown to attenuate endothelium-dependent vasodilation, it was of interest to verify whether general anesthesia would modify skin vasodilation in response to local pressure application, which is endothelium dependent. To study the effect of general anesthesia on pressure-induced vasodilation development, we examined the effects of low- and high-dose isoflurane. Skin blood flow was measured by laser Doppler flowmetry during 11.1 Pa s(-1) increases in locally applied pressure in anesthetized rats treated with low or high doses of isoflurane. Following the administration of low doses of isoflurane, skin blood flow increased from baseline, with increasing local pressure application (+37 +/- 10% at 2.0 kPa). The increase in skin blood flow was absent in rats treated with high doses (-20 +/- 5% at 2.0 kPa), even when the anesthesia-induced hypotension was corrected by gelofusine infusion (-20 +/- 10% at 2.0 kPa). Whereas sodium-nitroprusside-induced vasodilation developed following low and high doses of isoflurane, acetylcholine-induced vasodilation was impaired with high doses compared to low doses. These data show that pressure-induced vasodilation is abolished with high doses of anesthetics. It is not the anesthesia-induced hypotension, but the depth of anesthesia, which can lead to the disappearance of pressure-induced vasodilation by an alteration in endothelial function.
Fizanne
Lionel
L
UPRES EA 2170, Department of Medicine, Angers, France.
Fromy
Bérengère
B
Preckel
Marie-Pierre
MP
Sigaudo-Roussel
Dominique
D
Saumet
Jean Louis
JL
D000109:Acetylcholine / Q000494:pharmacology; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D004730:Endothelium, Vascular / Q000502:physiology; D005780:Gelatin / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D007022:Hypotension / Q000139:chemically induced / Q000517:prevention & control; D007530:Isoflurane / Q000494:pharmacology*; D008297:Male; D040542:Mechanotransduction, Cellular / Q000187:drug effects; D008833:Microcirculation / Q000187:drug effects; D009599:Nitroprusside / Q000494:pharmacology; D010952:Plasma Substitutes / Q000494:pharmacology; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000098:blood supply; D013386:Succinates / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology
D018685:Anesthetics, Inhalation; D010952:Plasma Substitutes; D013386:Succinates; D014665:Vasodilator Agents; D009599:Nitroprusside; C060085:succinylated gelatin; D005780:Gelatin; D007530:Isoflurane; D000109:Acetylcholine