Vasoconstrictor responses via P2X-receptors are selectively antagonized by NF023 in rabbit isolated aorta and saphenous artery.
1. The effects of NF023, the symmetrical 3'-urea of 8-(benzamido)naphthalene-1,3,5-trisulphonic acid), and its parent compound suramin were investigated on vasoconstrictor responses to alpha, beta-methylene ATP in rabbit isolated saphenous artery and vasodilator responses to ATP in noradrenaline-precontracted rabbit isolated thoracic aorta. 2. In rabbit isolated saphenous artery, alpha, beta-methylene ATP-induced vasoconstrictor responses via P2X-receptors were concentration-dependently and competitively antagonised by NF023 (30-300 microM; pA2 = 5.69 +/- 0.04). Suramin (100-1000 microM) also competitively blocked vasoconstrictor responses to alpha, beta-methylene ATP, albeit with lower potency (pA2 = 4.79 +/- 0.05). In contrast, NF023 (100 microM) did not significantly affect contractile responses to noradrenaline or histamine in the saphenous artery. 3. In noradrenaline-precontracted rabbit isolated thoracic aorta preparations, ATP (3-3000 microM) concentration-dependently induced relaxations via endothelium-dependent or smooth muscle P2Y-receptor subtypes. NF023 (30-300 microM) failed to block relaxant responses to ATP at endothelium-dependent P2Y-receptors, whereas suramin (100-1000 microM) did antagonise endothelium-dependent vasodilator responses to ATP. Neither NF023 (100 microM) nor suramin (300 microM) influenced vasorelaxant responses to ATP via endothelium-independent P2Y-receptors. 4. In conclusion, this study outlines the selectivity of NF023 as an effective P2X-receptor antagonist in rabbit isolated blood vessels without affecting endothelium-dependent or endothelium-independent P2Y-receptor subtypes, adrenoceptors or histamine receptors.
Ziyal
R
R
Department of Anatomy and Development Biology, University College London.
Ziganshin
A U
AU
Nickel
P
P
Ardanuy
U
U
Mutschler
E
E
Lambrecht
G
G
Burnstock
G
G
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000502:physiology; D001158:Arteries / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D058919:Purinergic P2 Receptor Antagonists; D011817:Rabbits; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D013498:Suramin / Q000031:analogs & derivatives* / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
C105374:NF023; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; D014662:Vasoconstrictor Agents; D013498:Suramin; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D009638:Norepinephrine