[SIN-1 interactions with the generation of cyclic nucleotides and arachidonate oxide metabolites in the uterine muscle].

In the uterine smooth muscle, SIN-1 stimulated cGMP accumulation independently of the presence of Ca2+ and activated the soluble form of guanylate-cyclase through mechanisms apparently similar to those involved in the stimulations evoked by NO-containing compounds. These activations appear different from those induced by hydroperoxy-unsaturated fatty acids and which contribute to the carbachol-mediated cGMP accumulation. SIN-1 did not influence the rise in cAMP of the biosynthesis of PG1(2) and 12-HETE due to exogenous arachidonic acid. By contrast, SIN-1 markedly inhibited the increased synthesis of PG1(2) induced by the ionophore A23187 which was due to a prior, Ca2+-dependent, liberation of endogenous arachidonic acid. The data suggests an interference of SIN-1 with the generation and/or the expression of the Ca2+ signal.