Corydalis amabilis Migo total alkaloids (COAMTA)

isolated from the root of Corydalis decumbens (Thunb) Pers

possessed inhibitory action on ADP-induced blood platelet aggregation and the formation of thrombus in animal experiments. Its effects on the platelet cyclic AMP and cyclic GMP in incubated rabbit platelet were measured by radioimmunoassay.

cAMP was significantly elevated when COAMTA was given 0.08—0.16mg/ml PRP. In concentration up to 0.16 mg/ml PRP

COAMTA elevated cGMP

but the ratio value of cAMP/cGMP was much higher than that of control group. These results suggest that the anti-platelet activity of COAMTA were mediated through elevation of cAMP levels.