Abstract Objective We examined the interaction of polymorphisms in the genes heme oxygenase- 1 (HMOX1) and nitric oxide synthase (NOS3) in patients with preeclampsia (PE) as well as the responsiveness to methyldopa and to total antihypertensive therapy. Methods The genes HMOX1 (rs2071746, A/T) and NOS3 (rs1799983, G/T) were genotyped using TaqMan allele discrimination assays (Applied Biosystems, Foster City, CA...