6533b857fe1ef96bd12b433a

RESEARCH PRODUCT

Effect of two phenanthrene alkaloids on angiotensin II-induced leukocyte-endothelial cell interactionsin vivo

Andrew C. IssekutzMaría Amparo BlázquezJavier López-martínMiguel Cerdá-nicolásJulio CortijoJosé-enrique O'connorMaria-jesus SanzRossana EstellésLara MilianM. Martinez-losaEdet M. AnamMaria Dolores IvorraEsteban J. Morcillo

subject

Pharmacologychemistry.chemical_classificationmedicine.medical_specialtyReactive oxygen speciesPlatelet-activating factorSuperoxideLeukocyte RollingPharmacologyN-Formylmethionine leucyl-phenylalanineAngiotensin IIEndothelial stem cellchemistry.chemical_compoundEndocrinologychemistryInternal medicinemedicineIntracellular

description

The present study has evaluated the effect of two phenanthrene alkaloids, uvariopsine and stephenanthrine, on angiotensin II (Ang-II)-induced leukocyte–endothelial cell interactions in vivo and the mechanisms involved in their activity. Intravital microscopy within the rat mesenteric microcirculation was used. A 60 min superfusion with 1 nM Ang-II induced a significant increase in the leukocyte–endothelial cell interactions that were completely inhibited by 1 μM uvariopsine cosuperfusion. A lower dose of 0.1 μM significantly reduced Ang-II-induced leukocyte adhesion by 75%. When Ang-II was cosuperfused with 1 and 0.1 μM stephenanthrine, Ang-II-induced leukocyte responses were significantly diminished. A lower dose of 0.01 μM only affected Ang-II-induced leukocyte adhesion. Both alkaloids inhibited Ang-II-induced endothelial P-selectin upregulation and the generation of reactive oxygen species (ROS) in endothelial cells stimulated with Ang-II, in fMLP-stimulated human neutrophils (PMNs) and in the hypoxanthine–xanthine oxidase system. However, cyclic AMP levels in PMNs stimulated with fMLP were not affected. Uvariopsine and stephenanthrine inhibited PAF-induced elevations in intracellular calcium levels in PMNs (IC50 values: 15.1 and 6.1 μM respectively) and blocked the binding of [3H]PAF to these leukocytes. They also reduced PAF-induced increases in intracellular levels of superoxide anion and hydrogen peroxide. In conclusion, stephenanthrine and uvariopsine are potent inhibitors of Ang-II-induced leukocyte accumulation in vivo. This effect appears to be mediated through ROS scavenging activity and blockade of PAF receptor. Thus, they have potential therapeutic interest for the control of leukocyte recruitment that occurs in cardiovascular disease states in which Ang-II is involved. British Journal of Pharmacology (2003) 140, 1057–1067. doi:10.1038/sj.bjp.0705525

https://doi.org/10.1038/sj.bjp.0705525