Preactivated monocytes from hypertensive patients as a factor for atherosclerosis?

Recently, we reported our findings regarding the elevated secretion pattern s of proinflammatory cytokines obtained from peripheral blood monocytes of hypertensive patients. To investigate the direct impact of these preactivat ed monocytes, the adhesion of monocytes from normal controls and hypertensi ve patients to vascular endothelial cell monolayers was determined spontane ously and after in vitro stimulation with either lipopolysaccharide (LPS) o r angiotensin II (Ang II), with or without preincubation with the ATI recep tor antagonist eprosartan. Peripheral blood monocytes from 20 patients and 20 healthy individuals were isolated by density gradient centrifugation and plastic adherence: endothelial cells were obtained from human umbilical co rds by collagenase digestion. The adhesion was determined by an assay with Cr-51-radiolabeled monocytes. Oxygen species release induced by phorbol myr istate acetate (PMA) as a further activation marker was analyzed for monocy tes and HUVEC by chemiluminescence (CL). Spontaneous adhesion of monocytes from patients: and the: adhesion after stimulation with Ang II were signifi cantly increased compared with normal controls (P < 0.05). Preincubation wi th eprosartan diminished the adhesion in both groups to comparable levels. In monocytes, peak levels of PMA and Ang II induced CL analysis were signif icantly higher in patients (P<0.005). These data indicate that preactivated monocytes from hypertensives may be of pathogenic importance in atheroscle rosis. (C) 2001 Elsevier Science Ireland Ltd. All rights: reserved.