Vasoactive substances produced by cultured rat brain endothelial cells

The vasoactive substances synthesized by primary cultures of rat brain endo thelial cells were investigated and compared to those from two, immortalize d cell lines, RBE4 and GP8. The vasoactivity of endothelium-derived substan ces was measured on isolated canine coronary artery. Vascular tone was sign ificantly decreased by both primary and GP8, but not by RBE4 cells. Indomet hacin pretreatment of primary and GP8 cells turned vasorelaxation into cont raction while N-omega-nitro-L-arginine pretreatment decreased the vasorelax ation induced by primary, but not by GPs cells. Eicosanoid production was d etermined after incubation with [C-14]arachidonic acid. The predominant vas oactive eicosanoid was prostaglandin E-2 in both primary and GP8 cells. RBE 4 cells synthetized mainly prostaglandin F-2 alpha and thromboxane B-2 and significantly less prostaglandin E-2 than did either primary or GP8 cells. The capacity of cerebral endothelium to regulate vascular tone by productio n of dilator and constrictor substances can be preserved under certain circ umstances in immortalized cell lines. (C) 1999 Elsevier Science B.V. All ri ghts reserved.