Effects of magnesium sulphate on placental expression of endothelin 1 and its receptors in preeclampsia

OBJECTIVES: To investigate the effects of magnesium sulphate (MgSO(4)) on placental expression of endothelin 1 (ET-1) and its receptors in preeclampsia (PE). DESIGN AND METHODS: Placentas were obtained from 10 normotensive (NT group) and 18 moderate preeclamptic (PE group) women. Among the PE group, 10 patients were treated with 0.9% NaCl solution (PES) and 8 women received MgSO(4) (PEMgSO(4)). Placental mRNAs of ET-1, ET-1(A) receptor (ET-1(A)R) and ET-1(B) receptor (ET-1(B)R) were evaluated by Northern blot and quantified using densitometry. RESULTS: Placental ET-1(B)R expression was lower (P<0.05) in the PES group without significant changes in the mRNAs of ET-1 and ET-1(A)R when compared with the NT group. MgSO(4) treatment was associated with decreased ET-1 and increased ET-1(B)R (P<0.05) expression, without significant changes in ET-1(A)R. CONCLUSIONS: The results of the present study showed that moderate PE is associated with low placental expression of ET-1(B)R, and MgSO(4) treatment resulted in placental expression changes of the ET-1/receptors system.