The Orail and Stim genes are recently identified store-operated Ca2+ channel molecules, which play an important role in essential physiological and pathophysiological functions from gene expression to cell growth (Zhang et al., 2005; Prakriya et al., 2006). In blood vessels, Orai and Stim proteins are involved in smooth muscle cell proliferation and migration (Potier et al., 2009). Here we aimed to examine the expression of Orai and Stim store-operated channel proteins in human arteries including the aorta, left internal mammary artery (LIMA), and renal artery in normal and diabetic kidney. The effect of high glucose on the gene expression was also investigated. Human aorta, left internal mammary artery and kidney samples were obtained from patients undertaken cardiac surgery or renal surgery in East Yorkshire NHS trust Hospitals with ethical approval by local ethical committee. The RT-PCR, western blotting and immunostaining were used. Arterial segments or primary cultured smooth muscle cells were treated with high glucose (25mM). The total RNA was extracted for RT-PCR and protein lysate was prepared for western blotting. The real-time PCR was used for gene quantification. All three isoforms of Orai (Orai1-3) and Stim1 and Stim2 were expressed in human aorta, LIMA and renal arteries, which were determined by RT-PCR, western blotting and immunostaining. The mRNA expression of Orai1 in the organ cultured LIMA was downregulated by the treatment with high glucose for 60 hours, while Orai2 and Orai3 were upregulated. The expression of Stim1 was also downregulated by high glucose treatment, but Stim2 expression was increased. The difference of gene expression in blood vessels was also observed in patients with diabetes. These results suggest store-operated channel molecules Orai and Stim are ubiquitously distributed in human vascular smooth muscle cells. The expression is regulated by high glucose and diabetic conditions, which suggest that store-operated channels could be important for the pathophysiology of diabetic blood vessel.