SHORT NOTE Cultured Microvascular Endothelial Cells Derived trom the Bovine Corpus Luteum Possess NCAM-140

Previously, five phenotypically different, stable types of microvascular endothelial cells (MVE) were isolated from the bovine corpus and cultured successfully. We found that three out of these five types of MVE express the neural cell adhesion moleeule (NCAM). As shown by immunocytochemistry. weak NCAM immunoreactivity occurred mainIy in the perinuclear area of cell type 1. Monolayers of types 2 and 5 revealed heavy NCAM immunoreactivity. which was localized predominantly at the lateral cell surface outlining the contact zones of adjacent cells. In contrast, cell types 3 and 4 were not NCAM immunoreactive. Western blot analyses substantiated these results: While cell type 1 showed a weak immunoreactive band, cell types 2 and 5 displayed strong NCAM-immunoreactive bands of a molecular weight of approximately 140 kDa (NCAM-140), which was absent in cell types 3 and 4. These results reveal for the first time that NCAM can be expressed by cultured MVE and may serve in mediating endothelial cell contacts. Since luteal cells also express NCAM140, this adhesion molecule could in addition be involved in the interactions of luteal cells with MVE.