title: Repeated phlebotomy augments angiogenesis to improve blood flow in murine ischemic legs.
abstract: Anemia may accelerate angiogenesis in ischemic organs through its ability to augment tissue hypoxia-induced generation of several known angiogenic factors and to increase erythropoietin levels, which are also potently angiogenic. We examined the effect of controlled phlebotomy (bloodletting) on blood flow in a mouse ischemic leg model. We ligated the right femoral artery of BALB/c mice. In the phlebotomy group, 200 microl of blood were drawn from the tail vein once a week. After 4 wk, blood flow in the ischemic leg was significantly better in the phlebotomy group (flow ratio of the ischemic to nonischemic leg, 0.87 + or - 0.04) than the control group (0.59 + or - 0.05, P < 0.05), and capillary density was significantly higher. Repeated phlebotomy increased serum erythropoietin levels as well as the expression of hypoxia-inducible transcription factor-1alpha and vascular endothelial growth factor and both the expression and activity of Akt and endothelial nitric oxide synthase (eNOS) in ischemic legs. Treatment with wortmannin or N(omega)-nitro-l-arginine methyl ester significantly attenuated the phlebotomy-induced improvement of blood flow. In addition, fluorescence-activated cell sorting analysis revealed an increase in circulating peripheral endothelial progenitor cells in the phlebotomy group, and treatment with AMD3100, a specific inhibitor of the chemokine receptor CXCR4, blocked the beneficial effect of phlebotomy. These findings suggest that repeated phlebotomy improves blood flow in ischemic legs through an angiogenic action that involves the Akt/eNOS pathway, endothelial progenitor cell mobilization, and their complicated cross talk. An adequately controlled phlebotomy might be one method by which to induce therapeutic angiogenesis.
authors.affiliation: Dept. of Cardiology, Gifu Univ. Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
authors.forename: Itta
authors.initials: I
authors.lastname: Kawamura
authors.forename: Genzou
authors.initials: G
authors.lastname: Takemura
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Kanamori
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takeyama
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Akiko
authors.initials: A
authors.lastname: Tsujimoto
authors.forename: Kazuko
authors.initials: K
authors.lastname: Goto
authors.forename: Rumi
authors.initials: R
authors.lastname: Maruyama
authors.forename: Takatomo
authors.initials: T
authors.lastname: Watanabe
authors.forename: Takeru
authors.initials: T
authors.lastname: Shiraki
authors.forename: Takuma
authors.initials: T
authors.lastname: Aoyama
authors.forename: Takako
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Shinya
authors.initials: S
authors.lastname: Minatoguchi
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001596:Benzylamines; D002196:Capillaries / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D000080027:Cyclams; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004921:Erythropoietin / Q000097:blood; D005263:Femoral Artery / Q000601:surgery; D006571:Heterocyclic Compounds / Q000494:pharmacology; D006614:Hindlimb; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D008026:Ligation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000098:blood supply*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000378:metabolism; D018962:Phlebotomy; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D012039:Regional Blood Flow; D015398:Signal Transduction; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D001596:Benzylamines; C514936:CXCR4 protein, mouse; D000080027:Cyclams; D004791:Enzyme Inhibitors; D006571:Heterocyclic Compounds; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019718:Receptors, CXCR4; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D004921:Erythropoietin; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; D051057:Proto-Oncogene Proteins c-akt; C088327:plerixafor; D019331:NG-Nitroarginine Methyl Ester; D000077191:Wortmannin