title: Feedback control of arterial smooth muscle tone: the role of prostacyclin.
abstract: Indomethacin potentiated noradrenaline (NA)-induced contractions of rabbit isolated mesenteric arteries. Mechanical removal of the endothelium did not influence its potentiating effect. Prostacyclin (PGI2) synthesis was stimulated by NA (0.1-1.0 mumol l-1) and inhibited by indomethacin in a concentration-dependent manner. There was a positive correlation between the indomethacin-induced inhibition of PGI2 formation and the indomethacin-evoked potentiation of contractile responses to NA. These results suggest that endogenous PGI2 plays a part in the feedback control of vascular smooth muscle tone.
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D016861:Cyclooxygenase Inhibitors; D011464:Epoprostenol / Q000096:biosynthesis / Q000502:physiology*; D005246:Feedback; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008638:Mesenteric Arteries / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects; D009129:Muscle Tonus; D009130:Muscle, Smooth / Q000502:physiology*; D011817:Rabbits; D011863:Radioimmunoassay
chemical_list: D016861:Cyclooxygenase Inhibitors; D015121:6-Ketoprostaglandin F1 alpha; D011464:Epoprostenol; D007213:Indomethacin