Adhesiveness of mononuclear cells in hypercholesterolemic humans is normalized by dietary L-arginine

Gregor Theilmeier, Jason R. Chan, Christoff Zalpour, Barbara Anderson, Bing Yin Wang, Andreas Wolf, Philip S. Tsao, John P. Cooke

Research output: Contribution to journalArticlepeer-review

69 Scopus citations


Hypercholesterolemia reduces vascular nitric oxide (NO) activity. This dysfunction may promote endothelial monocyte interaction as NO is a potent inhibitor of cell adhesion. We have previously shown that in hypercholesterolemic (HC) rabbits, chronic oral supplementation of L-arginine (Arg) restores NO activity and inhibits monocyte-endothelial cell interaction, in association with a reduction in atherogenesis. We hypothesized that enhancement of endothelial NO activity in HC humans would reduce monocyte adhesiveness. We used a functional binding assay to assess the adhesiveness of human mononuclear cells (MNCs) ex vivo to determine the effects of hypercholesterolemia and L-arginine administration. MNCs from HC subjects adhered in greater numbers (50% more cells per high-power field; P<.0001) than cells derived from normocholesterolemic (NC) subjects. To determine whether enhancement of endogenous NO activity could inhibit mononuclear cell adhesiveness, in a double-blinded placebo-controlled study, oral arginine HCl (8.4 g/d) was administered to HC subjects. Over a course of 2 weeks, this treatment abolished the increased adhesiveness of HC MNCs (160±11% versus 104±5%; before and after 2 weeks of Arg treatment; results expressed as a percentage of the binding values obtained using cells derived from paired NC individuals). By contrast, MNC adhesion remained significantly elevated in placebo-treated HC subjects. To examine whether endothelium- derived NO could act as a paracrine modulator of monocyte behavior, monocytes were exposed to NO donors or cocultured in the presence of endothelial cells exposed to antagonists of NO synthase in the presence or absence of L- arginine. NO donors inhibited monocyte adhesiveness. Furthermore, the adhesiveness of monocytes cocultured with endothelial cells was increased by antagonists of NO synthase; this effect was reversed by L-arginine. This study shows that the adhesiveness of human MNCs is increased by hypercholesterolemia. The increase in adhesiveness was reversed in vivo by administration of the NO precursor L-arginine. NO donors or endothelium- derived NO inhibits the adhesiveness of monocytes in vitro, supporting the hypothesis that the effects of L-arginine are mediated by NO.

Original languageEnglish (US)
Pages (from-to)3557-3564
Number of pages8
JournalArteriosclerosis, Thrombosis, and Vascular Biology
Issue number12
StatePublished - 1997


  • Adhesion
  • Atherosclerosis
  • Endothelium
  • Monocytes
  • Nitric oxide

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


Dive into the research topics of 'Adhesiveness of mononuclear cells in hypercholesterolemic humans is normalized by dietary L-arginine'. Together they form a unique fingerprint.

Cite this