ABSTRACT
<p><b>AIM</b>To investigate the mechanisms of 17beta-estradiol on the production of endothelin-1 in vascular smooth muscle cells.</p><p><b>METHODS</b>After incubation VSMC with various concentrations of 17beta-estradiol (10(-9) - 10(-7) mol/L) or plus L-NAME(10(- 6) mol/L) for different times, the concentration of endothelin-1 was measured. At the same time, the activity of endothelin converting enzyme-1 was analyzed, and the expression of preproET-1mRNA was measured by RT-PCR.</p><p><b>RESULTS</b>In basal conditions, 17beta-estradiol could inhibit the production of endothelin-1 in VSMC, and the action of 17beta-estradiol had nothing to do with the activity of endothelin converting enzyme-1. L-NAME inhibited the effect of 17-estradiol on the production of endothelin-1 in VSMC. RT-PCR results showed that 17-estradiol inhibited the preproET-1 mRNA expression, and whereas L-NAME reversed this action of 17beta-estradiol.</p><p><b>CONCLUSION</b>In basal conditions, 17beta-estradiol decreases the preproET-1 mRNA expression through NO-pathway to inhibit the production of endothelin-1 in cultured VSMC.</p>