Hyperglycaemia and advanced glycation end-products (AGE) are associated with oxidative stress and endothelial dysfunction in diabetes mellitus (Mann et al., 2003). We previously hypothesised that the generation of reactive oxygen species (ROS) by NAD(P)H oxidase, mitochondria or uncoupled endothelial nitric oxide synthase may upregulate antioxidant gene expression in endothelial cells via activation of the redox sensitive transcription factor Nrf2, which binds to the antioxidant response element (ARE) in the promoter region of target genes (Mann et al., 2007). In the present study, we examined the effects of elevated glucose and AGE-modified recombinant human serum albumin (AGE-HSA) on antioxidant gene expression in human umbilical vein endothelial cells (HUVEC). Endothelial cells were isolated by collagenase digestion and cultured in M199 containing 20% FCS. Confluent monolayers serum-deprived (1% FCS) for 4 h and then treated for 3-12 h with (i) elevated D-glucose (25 mM) and D-mannitol (20 mM + 5 mM glucose) as osmotic control) or (ii) AGE-HSA (100 μg/ml) and HSA (100 μg/ml) as a control. Elevated glucose increased heme oxygenase-1 (HO-1) expression after 6-12 h (Fig. 1), but had negligible effects on induction of either glutathione peroxidase-1 (GPx-1) or the phase II defence enzyme NAD(P)H:quinone oxidoreductase-1 (NQO1) (data not shown). Treatment of cells with AGE-HSA increased HO-1 expression after 3-6 h, which returned to basal levels after 12 h. AGE-HSA also increased expression of NQO1 but had negligible effects on GPx-1 expression. Our findings that hyperglycaemia and AGE-HSA induce adaptive antioxidant responses in fetal endothelial cells via the Nrf2/ARE pathway provide a basis for examining whether the phenotype of fetal endothelial cells is altered by in utero programming in gestational diabetes.