Effects of preanesthetic and anesthetic drugs on endothelium-dependent responses in the rat aorta.
1. Acetylcholine often fails to induce endothelium-dependent relaxation in human vessels in vitro. Due to the fact that most of these vessels come from surgery, we examined the influence of drugs used in anesthesia on endothelium-dependent responses in rat aorta. 2. Groups of male Wistar rats of the following treatments were utilized: P group, diazepam+promethazine+atropine; I group, pentothal+succinylcholine; IG group, halothane+nitrous oxide; M group, morphine+pancuronium; C group, untreated rats. Dose-response curves to noradrenaline and acetylcholine were determined in rat aorta in vitro, in the presence and absence of endothelium. 3. Acetylcholine induced more relaxation (P < 0.05) in the rat aorta of IG group compared with that of the C group. 4. In the rat aorta from P and IG groups, the contractions produced by several concentrations of noradrenaline were significantly smaller (P < 0.05) when the endothelium was removed. Similar effects occurred in aorta strips of animals previously treated with either atropine, promethazine, cimetidine or halothane. 5. Our results suggest that drugs currently used in anesthesia interfere with some endothelium-dependent effects on isolated rat aorta but according to these results they do not seem to be responsible for the lack of acetylcholine relaxation sometimes described in human vessels in vitro.
Molina
R
R
Dpto. Medicina, Fac. Medicina, Universidad de Oviedo, Spain.
Sánchez
M
M
Hidalgo
A
A
García de Boto
M J
MJ
D000109:Acetylcholine / Q000494:pharmacology; D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D011229:Preanesthetic Medication; D051381:Rats; D017208:Rats, Wistar
D000777:Anesthetics; D000109:Acetylcholine