Involvement of prostanoid release in the mediation of UTP-induced cerebrovascular contraction in the rat.
The interaction between uridine-5'-triphosphate (UTP) and prostanoids was studied in isolated rat middle cerebral arteries (MCAs). The strong contractions in MCA segments induced by UTP were weakened significantly by indomethacin and more markedly by the thromboxane receptor antagonist ICI 192605. Thromboxane A(2) (TXA(2)) release by MCAs was below the detection limit of the chemiluminescence enzyme immunoassay, but increased TXA(2) formation was detected in basilar arteries in the presence of UTP. Prostacyclin (PGI(2)) formation by MCAs also increased in the presence of UTP. These results suggest that UTP stimulates the release of both TXA(2) and PGI(2) from the rat MCA but the vascular effect of TXA(2) is dominant.
Department of Physiology, Ludwig-Maximilians University, Munich, Germany.
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Lacza
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Káldi
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Kövecs
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Görlach
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Nagy
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Sándor
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Benyó
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Wahl
D000818:Animals; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D011464:Epoprostenol / Q000378:metabolism; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D020768:Middle Cerebral Artery / Q000187:drug effects / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013928:Thromboxane A2 / Q000378:metabolism*; D014544:Uridine Triphosphate / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D016861:Cyclooxygenase Inhibitors; D004146:Dioxanes; C057498:ICI 192605; D013928:Thromboxane A2; D011464:Epoprostenol; D014544:Uridine Triphosphate; D007213:Indomethacin