RESUMO
AIM: To investigate the effect of caveolin - 1 and phosphorylation of ERK1/2 on 17β - estradiol ( E_2 ) induced inhibition of vascular smooth muscle cells ( VSMCs ). METHODS: The proliferation in cultured VSMCs was determined by using [~3H ] - thymidine incorporation. The expressions of caveolin - 1, MKP -1 and ERK1/2 phosphorylation were measured by Western blotting. The expression of caveolin - 1 mRNA was measured by RT - PCR. RESULTS: Exposed to fetal calf serum ( FCS) for 24 h, the increase in proliferation of VSMCs was detected by [~3H] -thymidine incorporation. Pretreatment with various concentrations of E_2 for 24 h inhibited VSMC proliferation induced by FCS. The results of Western blotting and RT - PCR showed that pretreated with 17β - estradiol for 24 h reserved the decrease in caveolin - 1 induced by FCS. Western blotting results further proved that the expression of MKP - 1 was significantly increased and the expression of ERK1/2 phosphorylation was decreased after incubated with 17β - estradiol. CONCLUSION: 17β -estradiol increases caveolin - 1 and MKP - 1 expressions, and decreases ERK1/2 phosphorylation, leading to the inhibition of VSMC proliferation.