Response to noradrenaline and histamine in normal and sensitized guinea pig aorta and its relation to endothelium.
Pharmacological reactivity of sensitized blood vessels has been less studied than that of airways. Aorta rings were obtained from normal and actively sensitized guinea pigs and prepared for isometric recording of tension changes. Noradrenaline (10 nM-10 microM), histamine (0.1 microM-0.1 mM) and KCl (10-100 mM) produced concentration-related contractions of normal tissues. Removal of endothelium resulted in a marked left upward shift of the concentration-response curve to noradrenaline but it did not alter histamine- or KCl-induced responses. Pretreatment with ibuprofen (10 microM) or L-NG-nitroarginine (L-NOARG, 3.3 microM) enhanced noradrenaline-induced responses without affecting those to histamine or KCl. Removal of endothelium or pretreatment with ibuprofen or L-NOARG did not alter agonist-induced responses in sensitized tissues. Neuronal uptake and release of [3H]-noradrenaline did not differ in normal and sensitized tissues. Loss of the modulatory role of endothelium and other mechanisms may be involved in the hyperreactivity of sensitized guinea pig aorta.
Pascual
R
R
Departamento de Fisiología y Farmacología, Universidad de Alcalá de Henares, Madrid, Spain.
Villanueva
M M
MM
Perpiña
M
M
Ortiz
J L
JL
Barrachina
M D
MD
Cortijo
J
J
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects
D011189:Potassium Chloride; D006632:Histamine; D009638:Norepinephrine