Taurine and icosanoids in the heart

Experiments were carried out on non-working isolated rabbit hearts perfused by Tyrode solution: the effects of Taurine introduced into the coronary circulation were studied • - on the biosynthesis of the anti-thromboxane synthetase factor (“FATS”) • - and on the TXA2 and PGI2 synthetase activities of cardiac tissue. The effects of Taurine were simultaneously studied on the biosynthesis of TXA2 and PGI2 in vitro . Experiments performed under the adopted conditions have shown that • - in vitro Taurine did not significantly modify the biosynthesis of TXA2 and PGI2 • - ex vivo Taurine did not change the biosynthesis of “FATS” but inhibited both TXA2 and PGI2 synthetase activities of the cardiac tissue: Taurine was more active on the TXA2 synthetase activity than on the PGI2 one. Thus Taurine promoted the formation of vasodilator and antiaggregating PGI2 at the expenses of vasoconstrictor and proaggregating TXA2. This could at least partly explain the beneficial effects of Taurine in the physiopethology of the heart.