Effects of partial blood replacement with pyridoxalated hemoglobin polyoxyethylene conjugate solution on transient cerebral ischemia in gerbil.
Blood components were reported to be aggravating factors of ischemic cerebral injury. We previously reported that a partial blood replacement with Fluosol DA reduced ischemic neuronal injury. The purpose of this study is to elucidate whether pyridoxalated hemoglobin polyoxyethylene conjugate solution (PHP) exerts neuro-projective effects against cerebral ischemia.


METHODS
38 adult male gerbils were divided into 4 groups, such as normal group without ischemia or treatment, PHP group undergoing an exchanging blood transfusion with 5.0 ml PHP, ischemia group undergoing 5-min forebrain ischemia, and PHP-ischemia group with 5.0 ml PHP partial blood replacement prior to 5-min forebrain ischemia. Cerebral injury was assessed 7 days after treatment. In another group, effects of PHP on blood nitric oxide (NO) and cerebral blood flow (CBF) were studied.


RESULTS
CA1 cell density was 140-2/mm in normal group and 142-5/mm in PHP group. The cell density was markedly reduced to 38-13 in ischemia group. The cell density was further reduced 27-10/mm in PHP-ischemia group. PHP was found to have a potent NO scavenger action and reduce CBF.


CONCLUSIONS
Partial blood replacement with PHP prior to ischemia may cause cerebral vasoconstriction due to NO scavenger action and may worsen ischemic injury.
Hanzawa
K
K
Niigata University School of Medicine, Japan.
Ohzeki
H
H
Moro
H
H
Eguchi
S
S
Nakajima
T
T
Makifuchi
T
T
Miyashita
K
K
Nishiura
M
M
Naritomi
H
H
D000818:Animals; D001802:Blood Substitutes / Q000494:pharmacology*; D002452:Cell Count; D002560:Cerebrovascular Circulation / Q000502:physiology; D005849:Gerbillinae; D006454:Hemoglobins / Q000494:pharmacology*; D002546:Ischemic Attack, Transient / Q000378:metabolism / Q000628:therapy*; D017078:Laser-Doppler Flowmetry; D008297:Male; D009569:Nitric Oxide / Q000097:blood; D011092:Polyethylene Glycols / Q000494:pharmacology*; D016548:Prosencephalon / Q000098:blood supply / Q000378:metabolism
D001802:Blood Substitutes; D006454:Hemoglobins; C050907:pyridoxalated-hemoglobin-polyethylene glycol conjugate; D009569:Nitric Oxide; D011092:Polyethylene Glycols