ABSTRACT
Cultured porcine endothelial cells (EC) produce and secrete plasminogen activators (PA). If the serum free medium conditioned by vascular smooth muscle cells (SMC-CM) mixed with the medium conditioned by endothelial cells (EC-CM), the PA activities of the latter decreased significantly. Coeultivation of EC with SMC inhibited 70.7% PA activity of EC. Gel eletrophoretic analysis (SDS-PAGE) of SMC-CM followed by reverse fibrin autography demonstrated PA inhibitory activity in the molecular weight range of 49, 000-52, 000 similar to those identified by Laug (1985).In this study it was also investigated the effect of a Chinese herbal medicine-Radix Salviae Miltiorrhizae (RSM) on the inhibitory activity. SMC were incubated with RSM (0.1% in M-199, the final concentration was 1.5mg/ml) for 24hr. The SMC-CM collected before and after RSM treatment were mixed with EC-CM and urokinase respectively. The results show that the residual PA activities in EC-CM or urokinase samples mixed with SMC-CM treated with RSM were significantly higher than that mixed with SMC-CM without treatment with RSM. SMC-CM neutralized the PA activities in EC-CM or urokinase samples in a concentration dependent manner (P