Thromboxane A2, as an unstable intermediate between the prostaglandin endoperoxides and thromboxane B2, is a potent inducer of platelet aggregation and causes vasoconstriction.
15(R)-Pinane thromboxane A2 is the (R)-epimer of pinane thromboxane A2 . 15(R)-PTA2 does not inhibit collagen-induced platelet aggregation (IC50s = 120-130 μM). It does not affect gastric tone in isolated rat gastric fundus when used at concentrations of 0.5 or 1.5 μg/ml and is less effective than PTA2 at inhibiting prostaglandin-induced contraction of isolated rat stomach muscle.