Comparison of vascular and platelet thromboxane A2/prostaglandin H2 receptors in the pig

Characterization of Thromboxane A2/Prostaglandin H2 Receptors in Porcine Coronary Artery -The Inhibitory Effect of a Novel Dibenzoxepin Derivative, KW-3635

“…In contrast, the Br.u* value remained the same in the presence and absence of Ca2*. These K6 values with or without Ca2+ and the B-u* value were similar to those of [3H]SQ 29,548 binding to porcine thoracic aorta (21). In porcine thoracic arterial membranes , Ca'* also increases the affinity of [3H]U466I9 (7) or 13H1S-1+S Q2), a TX A2IPGH2 receptor antagonist.…”

“…The K1 values of U466I9, SQ BM13505, a non-prostanoic TXA2 antagonist. TXA2 is a potent mediator which induces contraction of the coronary artery (21). TXA2 antagonists such as SQ 29,548 (24) and BM13505 (25) reduced the extent of dam age and infarct size following myocardial ischemia plus reperfusion in dogs.…”

Mediation of bradykinin‐induced contraction in canine veins via thromboxane/prostaglandin endoperoxide receptor activation

“…Radioligand studies in pig aorta have shown that binding of [3H]-U44619 to the TXA2/PGH2 receptor can be inhibited by PGF2. (Mihara et al, 1989). This interaction of PGF2.…”

“…SQ29548 is a TXA2/PGH2 receptor antagonist which selectively binds to TXA2/PGH2 receptors (Mihara et al, 1989) and inhibits TXA2 analogue-induced vascular contraction (Ogletree et al, 1985;Darius et al, 1985;Mihara et al, 1989). It effectively blocked the BK-induced contraction in canine jugular and femoral veins at concentrations as low as 10-8M (Figure 4).…”

“…However, in vascular preparations containing TXA2/PGH2 receptors, PGF2. is significantly less potent than PGH2 and TXA2 (Hamberg et al, 1975b;Coleman et al, 1981), the PGH2 analogue U44069 (Tore et al, 1984) and the TXA2 mimetic U44619 (Mihara et al, 1989).…”