['The mechanism of atherogenesis includes leukocyte adhesion to endothelial cells followed by migration into the subendothelial space. The polysialylated neural cell adhesion molecules (PSA-nCAMs) are a group of hydrophilic neural cell adhesion molecule (NCAM) isoforms that inhibit NCAM: NCAM association, thereby blocking cell: cell adhesion. During previous studies, we demonstrated that sialylation of specific NCAMs are upregulated at proestrus in the rat and that PSA-nCAM is expressed by the rat vascular endothelium.', 'In this study, we sought the presence of PSA-nCAM in human vessels and regulation of its expression in estradiol-treated human umbilical vascular endothelial cells (HUVEC). Immunoreactive PSA-nCAM (ir-PSA-nCAM) was shown in blood and lymph vessels of adult rats and human brain, skin, liver, lung, cervix, endometrium, and ovary. Staining for ir-PSA-nCAM was present on the glycocalyceal surface of estradiol-treated HUVEC, but not in the presence of the estrogen receptor (ER)-blocker fulvestrant. Western blotting confirmed these findings.'] Does estradiol regulate expression of polysialated neural cell adhesion molecule by human vascular endothelial cells?