In vivo reduction of cell-free methemoglobin to oxyhemoglobin results in vasoconstriction in canines

© 2013 American Association of Blood Banks..

BACKGROUND: Cell-free hemoglobin (Hb) in the vasculature leads to vasoconstriction and injury. Proposed mechanisms have been based on nitric oxide (NO) scavenging by oxyhemoglobin (oxyHb) or processes mediated by oxidative reactions of methemoglobin (metHb). To clarify this, we tested the vascular effect and fate of oxyHb or metHb infusions.

STUDY DESIGN AND METHODS: Twenty beagles were challenged with 1-hour similar infusions of (200 μmol/L) metHb (n = 5), oxyHb (n = 5), albumin (n = 5), or saline (n = 5). Measurements were taken over 3 hours.

RESULTS: Infusions of the two pure Hb species resulted in increases in mean arterial blood pressure (MAP), systemic vascular resistance index, and NO consumption capacity of plasma (all p < 0.05) with the effects of oxyHb being greater than that from metHb (MAP; increase 0 to 3 hr; 27 ± 6% vs. 7 ± 2%, respectively; all p < 0.05). The significant vasoconstrictive response of metHb (vs. albumin and saline controls) was related to in vivo autoreduction of metHb to oxyHb, and the vasoactive Hb species that significantly correlated with MAP was always oxyHb, either from direct infusion or after in vivo reduction from metHb. Clearance of total Hb from plasma was faster after metHb than oxyHb infusion (p < 0.0001).

CONCLUSION: These findings indicate that greater NO consumption capacity makes oxyHb more vasoactive than metHb. Additionally, metHb is reduced to oxyHb after infusion and cleared faster or is less stable than oxyHb. Although we found no direct evidence that metHb itself is involved in acute vascular effects, in aggregate, these studies suggest that metHb is not inert and its mechanism of vasoconstriction is due to its delayed conversion to oxyHb by plasma-reducing agents.

Medienart:

E-Artikel

Erscheinungsjahr:

2013

Erschienen:

2013

Enthalten in:

Zur Gesamtaufnahme - volume:53

Enthalten in:

Transfusion - 53(2013), 12 vom: 16. Dez., Seite 3149-63

Sprache:

Englisch

Beteiligte Personen:

Wang, Dong [VerfasserIn]
Piknova, Barbora [VerfasserIn]
Solomon, Steven B [VerfasserIn]
Cortes-Puch, Irene [VerfasserIn]
Kern, Steven J [VerfasserIn]
Sun, Junfeng [VerfasserIn]
Kanias, Tamir [VerfasserIn]
Gladwin, Mark T [VerfasserIn]
Helms, Christine [VerfasserIn]
Kim-Shapiro, Daniel B [VerfasserIn]
Schechter, Alan N [VerfasserIn]
Natanson, Charles [VerfasserIn]

Links:

Volltext

Themen:

31C4KY9ESH
9008-37-1
Albumins
Journal Article
Methemoglobin
Nitric Oxide
Oxyhemoglobins
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 03.02.2014

Date Revised 21.10.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/trf.12162

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM225779447