Effect of two phenanthrene alkaloids on angiotensin II-induced leukocyte-endothelial cell interactions in vivo.
1. 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. 2. 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 microm uvariopsine cosuperfusion. A lower dose of 0.1 microm significantly reduced Ang-II-induced leukocyte adhesion by 75%. 3. When Ang-II was cosuperfused with 1 and 0.1 microm stephenanthrine, Ang-II-induced leukocyte responses were significantly diminished. A lower dose of 0.01 microm only affected Ang-II-induced leukocyte adhesion. 4. 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. 5. Uvariopsine and stephenanthrine inhibited PAF-induced elevations in intracellular calcium levels in PMNs (IC50 values: 15.1 and 6.1 microm 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. 6. 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.
Estellés
Rossana
R
Department of Pharmacology, Faculty of Medicine, University of Valencia, Avda Blasco Ibañez, 17, E-46010 Valencia, Spain.
López-Martín
Javier
J
Milian
Lara
L
O'Connor
José-Enrique
JE
Martínez-Losa
Magdalena
M
Cerdá-Nicolás
Miguel
M
Anam
Edet M
EM
Ivorra
María Dolores
MD
Issekutz
Andrew C
AC
Cortijo
Julio
J
Morcillo
Esteban J
EJ
Blázquez
Maria Amparo
MA
Sanz
Maria-Jesús
MJ
D000249:Adenosine Monophosphate / Q000378:metabolism; D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002450:Cell Communication / Q000187:drug effects; D002460:Cell Line; D005576:Colforsin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D036904:Leukocyte Rolling / Q000187:drug effects; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D018715:Microscopy, Video; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010616:Phenanthrenes / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry; D010972:Platelet Activating Factor / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D020889:Rolipram / Q000494:pharmacology
D000470:Alkaloids; D010616:Phenanthrenes; D010936:Plant Extracts; D010972:Platelet Activating Factor; D017382:Reactive Oxygen Species; C488565:uvariopsine; D005576:Colforsin; C049411:stephenanthrine; D000249:Adenosine Monophosphate; C031181:phenanthrene; D009240:N-Formylmethionine Leucyl-Phenylalanine; D020889:Rolipram; D002118:Calcium