Transfusion of hemoglobin-based oxygen carriers in the carboxy state is beneficial during transient focal cerebral ischemia.

Abstract

Exchange transfusion of large volumes of hemoglobin (Hb)-based oxygen carriers can protect the brain from middle cerebral artery occlusion (MCAO). Hb in the carboxy state (COHb) may provide protection at relatively low volumes by enhancing vasodilation. We determined whether transfusion of rats with 10 ml/kg PEGylated COHb [polyethylene glycol (PEG)-COHb] at 20 min of 2-h MCAO was more effective in reducing infarct volume compared with non-carbon monoxide (CO) PEG-Hb. After PEG-COHb transfusion, whole blood and plasma COHb was <3%, indicating rapid release of CO. PEG-COHb transfusion significantly reduced infarct volume (15 ± 5% of hemisphere; mean ± SE) compared with that in the control group (35 ± 6%), but non-CO PEG-Hb did not (24 ± 5%). Chemically dissimilar COHb polymers were also effective. Induction of MCAO initially produced 34 ± 2% dilation of pial arterioles in the border region that subsided to 10 ± 1% at 2 h. Transfusion of PEG-COHb at 20 min of MCAO maintained pial arterioles in a dilated state (40 ± 5%) at 2 h, whereas transfusion of non-CO PEG-Hb had an intermediate effect (22 ± 3%). When transfusion of PEG-COHb was delayed by 90 min, laser-Doppler flow in the border region increased from 57 ± 9 to 82 ± 13% of preischemic baseline. These data demonstrate that PEG-COHb is more effective than non-CO PEG-Hb at reducing infarct volume, sustaining cerebral vasodilation, and improving collateral perfusion in a model of transient focal cerebral ischemia when given at a relatively low dose (plasma Hb concentration < 1 g/dl). Use of acellular Hb as a CO donor that is rapidly converted to an oxygen carrier in vivo may permit potent protection at low transfusion volumes.

• Authors: Jian Zhang, Suyi Cao, Herman Kwansa, Daina Crafa, Kathleen K Kibler, Raymond C Koehler
• Journal: Journal of applied physiology (Bethesda, Md. : 1985) (J Appl Physiol (1985)) Vol. 113 Issue 11 Pg. 1709-17 (Dec 01 2012) ISSN: 1522-1601 [Electronic] United States
• PMID: 23042910 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Blood Substitutes
• Hemoglobins
• Neuroprotective Agents
• PEG-hemoglobin
• Carbon Dioxide
• Polyethylene Glycols
• Carboxyhemoglobin

Topics

• Animals
• Blood Substitutes (administration & dosage, metabolism, pharmacology)
• Brain (blood supply, drug effects, metabolism, pathology, physiopathology)
• Carbon Dioxide (blood)
• Carboxyhemoglobin (administration & dosage, analogs & derivatives, metabolism, pharmacology)
• Cerebral Arteries (drug effects, physiopathology)
• Cerebrovascular Circulation (drug effects)
• Disease Models, Animal
• Hemoglobins (administration & dosage, metabolism, pharmacology)
• Infarction, Middle Cerebral Artery (blood, pathology, physiopathology, prevention & control)
• Infusions, Intravenous
• Ischemic Attack, Transient (blood, pathology, physiopathology, prevention & control)
• Male
• Neuroprotective Agents (administration & dosage, metabolism, pharmacology)
• Polyethylene Glycols (administration & dosage, metabolism, pharmacology)
• Rats
• Rats, Wistar
• Time Factors
• Vasodilation (drug effects)