Dataset Information

Sequestration of extracellular hemoglobin within a haptoglobin complex decreases its hypertensive and oxidative effects in dogs and guinea pigs.

ABSTRACT: Release of hemoglobin (Hb) into the circulation is a central pathophysiologic event that contributes to morbidity and mortality in chronic hemolytic anemias and severe malaria. These toxicities arise from Hb-mediated vasoactivity, possibly due to NO scavenging and localized tissue oxidative processes. Currently, there is no established treatment that targets circulating extracellular Hb. Here, we assessed the role of haptoglobin (Hp), the primary scavenger of Hb in the circulation, in limiting the toxicity of cell-free Hb infusion. Using a canine model, we found that glucocorticoid stimulation of endogenous Hp synthesis prevented Hb-induced hemodynamic responses. Furthermore, guinea pigs administered exogenous Hp displayed decreased Hb-induced hypertension and oxidative toxicity to extravascular environments, such as the proximal tubules of the kidney. The ability of Hp to both attenuate hypertensive responses during Hb exposure and prevent peroxidative toxicity in extravascular compartments was dependent on Hb-Hp complex formation, which likely acts through sequestration of Hb rather than modulation of its NO- and O2-binding characteristics. Our data therefore suggest that therapies involving supplementation of endogenous Hb scavengers may be able to treat complications of acute and chronic hemolysis, as well as counter the adverse effects associated with Hb-based oxygen therapeutics.

SUBMITTER: Boretti FS

PROVIDER: S-EPMC2719941 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature

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Sequestration of extracellular hemoglobin within a haptoglobin complex decreases its hypertensive and oxidative effects in dogs and guinea pigs.

Boretti Felicitas S FS Buehler Paul W PW D'Agnillo Felice F Kluge Katharina K Glaus Tony T Butt Omer I OI Jia Yiping Y Goede Jeroen J Pereira Claudia P CP Maggiorini Marco M Schoedon Gabriele G Alayash Abdu I AI Schaer Dominik J DJ

The Journal of clinical investigation 20090720 8

Release of hemoglobin (Hb) into the circulation is a central pathophysiologic event that contributes to morbidity and mortality in chronic hemolytic anemias and severe malaria. These toxicities arise from Hb-mediated vasoactivity, possibly due to NO scavenging and localized tissue oxidative processes. Currently, there is no established treatment that targets circulating extracellular Hb. Here, we assessed the role of haptoglobin (Hp), the primary scavenger of Hb in the circulation, in limiting t ...[more]

PMID: 19620788

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Dataset Information

Sequestration of extracellular hemoglobin within a haptoglobin complex decreases its hypertensive and oxidative effects in dogs and guinea pigs.

Publications

Sequestration of extracellular hemoglobin within a haptoglobin complex decreases its hypertensive and oxidative effects in dogs and guinea pigs.

Similar Datasets

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