Abstract

Endothelial cells of the human umbilical blood vessels are widely cultured in an oxygen tension (21%) far above that in which they exist in vivo (3%). This study investigates the effect of the long term culture (ca. 1 month) of human umbilical artery endothelial cells in a reduced oxygen environment (3%: HUAEC3) in comparison to cells grown in a ‘normoxic’ environment (21%: HUAEC21). Despite reports of altered metabolic pathways and reduced membrane integrity in other cell types, the characteristics of HUAEC3 were found to be similar to those of HUAEC21 with respect to morphology, immunocytochemical profile and in vitro growth rates. Cellular glutathione was maintained in these cells although ATP levels in HUAEC3 were found to be significantly lower than those observed in HUAEC21. The phosphoinositide responses of the HUAEC3 to a variety of agonists were also found to be of similar magnitude to those observed in HUAEC21. In addition, the pharmacological characteristics of the phospholipase C-linked histamine H1 and P2y2 (P2U) receptors were not changed by culture of cells in a low oxygen environment.