Efecto de la progesterona sobre la agregación plaquetaria y la produccion de eicosanoides por aorta de rata

POLINI NÉLIDA; MASSHEIMER VIRGINIA; SELLES JUANA

ACTA BIOQUíMICA CLíNICA LATINOAMERICANA

Año: 2004 vol. 38 p. 281 - 287

0325-2957

Using rat aortic tissue we studied the non genomic action of Progesterone (Pg) on  nitric oxide (NO), prostacyclin (PGI2), and tromboxane (Tx) synthesis and its relationship with platelet aggregation. Treatment of female rat aortic rings (RAS) with Pg induced a dose-dependent inhibition of platelet aggregation (IPA), which was partially abolished when RAS were treated in the presence of  the specific NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME). This observation would indicate that the inhibition of platelet aggregation (PA) resulted partially dependent of NOS stimulation by the hormone. Pg also produced a dose-dependent increase in PGI2 synthesis (42 at 182% respect of control), but no changes in Tx liberation by aorta was observed, at all concentrations of Pg used. RAS preincubation with  indomethacine, a COX inhibitor, partially reduced Pg antiaggregatory  effect, suggesting that the inhibition of PA induced by hormone is also dependent on PGI2 generation. Our results provide evidences that Pg modulates PA involving NO and PGI2 metabolic pathways.