title: Opposing actions of angiotensins on angiogenesis.
abstract: Using the murine sponge model of angiogenesis, associated to functional and morphological parameters we have demonstrated opposing actions of angiotensin II (Ang II) and angiotensin-(1-7;Ang-1-7) in modulating fibrovascular tissue growth. Angiogenesis in the implants was assessed at day 7 postimplantation by extracting the hemoglobin content, by determining the outflow rate of sodium fluorescein applied intraimplant and by histological analysis. Furthermore, the proliferative activity of control and angiotensin-treated implants was established using the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2(4 -sulfonyl)2H-tetrazolium)assay. The hemoglobin content in the control implants was 2.4 +/- 0.14 (microg/mg wet weight) versus 3.6 +/- 0.27(Ang II;100 ng) and 0.86 +/- 0.07 Ang-(1-7); 20 ng. Blood flow in the implants as determined by t1/2 values (time taken for the fluorescence to reach 50% of the peak in the systemic circulation) showed that Ang II stimulated angiogenesis, whereas Ang-(1-7) inhibited it. The proliferative activity of the sponge-induced fibrovascular tissue was enhanced by Ang II and diminished by Ang-(1-7). These results show the pro-versus anti-angiogenic effects of these angiotensin molecules, providing evidence for their opposing effects on vascular tissue growth and wound healing in vivo.
authors.affiliation: Department of Physiology and Biophysics Institute of Biological Sciences-Federal University of Minas Gerais, Belo Horizonte/MG-Brazil.
authors.forename: R D
authors.initials: RD
authors.lastname: Machado
authors.forename: R A
authors.initials: RA
authors.lastname: Santos
authors.forename: S P
authors.initials: SP
authors.lastname: Andrade
mesh_terms: D000803:Angiotensin I; D000804:Angiotensin II / Q000502:physiology*; D000818:Animals; D002455:Cell Division; D008297:Male; D051379:Mice; D018919:Neovascularization, Physiologic; D010446:Peptide Fragments / Q000502:physiology; D014945:Wound Healing / Q000502:physiology*
chemical_list: D010446:Peptide Fragments; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)