Vascular effects of isoprostanes after endothelial damage.
The isoprostanes, 8-iso-PGF2alpha and 8-iso-PGE2, are powerful vasoconstrictors in vitro and in vivo. Increased formation of 8-iso-PGF2alpha was detected in atherosclerotic patients. In this disease endothelial injuries appear, followed by a reduced release of nitric oxide (NO). Our results show that the vasoconstrictor effects of 8-iso-PGF2alpha as well as of 8-iso-PGE2 were amplified after endothelial damage of the vasculature of the isolated perfused rabbit ear. Also vasoconstrictions induced by both isoprostanes were amplified by perfusions with the NO-synthase blocker N(G)-nitro-L-arginine methylester (L-NAME) at a final concentration of 100 micromol/l. Therefore, we can assume that the amplification of the vasoconstrictor effects of the isoprostanes used after damage of endothelium might be mainly due to the reduced formation of NO.
Sametz
W
W
Department of Biomedical Research, University of Graz, Austria. wolfgang.sametz@kfunigraz.ac.at
Prasthofer
S
S
Wintersteiger
R
R
Juan
H
H
D000818:Animals; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000494:pharmacology; D015232:Dinoprostone / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004431:Ear, External / Q000098:blood supply; D004730:Endothelium, Vascular / Q000293:injuries*; D028441:F2-Isoprostanes; D005260:Female; D066298:In Vitro Techniques; D007536:Isomerism; D028421:Isoprostanes; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D011817:Rabbits; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D028441:F2-Isoprostanes; D028421:Isoprostanes; D014662:Vasoconstrictor Agents; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost; D015232:Dinoprostone; D019331:NG-Nitroarginine Methyl Ester; C011987:8-isoprostaglandin E2