title: Erythrocyte deformability and nitric oxide mobilization under pannexin-1 and PKC dependence.
abstract: The erythrocyte adenosine triphosphate (ATP) is utilised for protein phosphorylation and exported through the pannexin 1 hemichannel (Px1) in the microcirculation. The physiological stimuli for ATP release are dependent of blood shear rate level and of the tissue oxygen content. The deoxygenated and oxygenated states of haemoglobin are respectively bound and unbound to N terminal domain of the protein band 3 of the erythrocyte membrane in dependence of its degree of phosphorylation. The protein tyrosine kinase (PTK) and protein tyrosine phosphatase (PTP) contribute to the phosphorylation degree of band 3 and are modulated by protein kinase C (PKC). Chelerythrine (Che) is a competitive inhibitor of ATP for PKC and a negative modulator of erythrocyte deformability. The aim of this study was to assess the mobilization of nitric oxide (NO) in erythrocyte in absence and presence of Che and Px1 inhibitor (carbenoxolone). Erythrocyte deformability was evaluated in presence of carbenoxolone (Carb). Regarding the effects observed in the erythrocyte by presence of Che or Carb, the values of efflux of NO and the concentration of nitrosogluthatione are similar and with no changes in relation to their absence. Px1inhibition by Carb 10 μM ameliorates the erythrocyte deformability at a shear force of 0.6 and 1.2 Pa. The PKC inhibitor shows similar effects to the Carb on the mobilization of nitric oxide in erythrocyte. The blockage of ATP release by Carb from erythrocytes suggests a possible benefit to develop in ischemia reperfusion or in inflammatory response where will be needed to rescue the excess of NO present and ameliorate the red blood cell deformability at low shear rates.
authors.affiliation: Unidade de Biologia Microvascular e Inflamação, Instituto de Medicina Molecular, Instituto de Bioquímica, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: A S
authors.initials: AS
authors.lastname: Silva-Herdade
authors.affiliation: Unidade de Biologia Microvascular e Inflamação, Instituto de Medicina Molecular, Instituto de Bioquímica, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: T
authors.initials: T
authors.lastname: Freitas
authors.affiliation: Unidade de Biologia Microvascular e Inflamação, Instituto de Medicina Molecular, Instituto de Bioquímica, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: J Pedro
authors.initials: JP
authors.lastname: Almeida
authors.affiliation: Unidade de Biologia Microvascular e Inflamação, Instituto de Medicina Molecular, Instituto de Bioquímica, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Saldanha
mesh_terms: D000818:Animals; D017630:Connexins / Q000235:genetics* / Q000378:metabolism*; D004907:Erythrocyte Deformability / Q000235:genetics*; D006439:Hemodynamics; D006801:Humans; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism*; D009569:Nitric Oxide / Q000235:genetics*; D011493:Protein Kinase C / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction
chemical_list: D017630:Connexins; D009419:Nerve Tissue Proteins; C492764:PANX1 protein, human; D009569:Nitric Oxide; D011493:Protein Kinase C
keywords: Erythrocyte; carbenoxolone nitric oxide; pannexin 1; protein kinase C