Oxygen treatment restores energy status following experimental neonatal hypoxia-ischemia.
OBJECTIVE
The purpose of this study was to determine whether oxygen treatment could attenuate the alterations in cerebral energy metabolism found in the brain following hypoxia-ischemia.


METHODS
Seven-day-old rat pups were subjected to unilateral carotid artery ligation followed by 2 hrs of hypoxia (8% oxygen at 37 degrees C). The concentrations of high-energy phosphate compounds and glycolytic intermediates and the activity of Na+/K+-adenosine triphosphatase were measured at 4-72 hrs of recovery. Brain weight was used to determine the severity of the brain injury at 2 wks after insult.


METHODS
Experimental setting.


METHODS
Rat pups.


METHODS
Pups were treated with 100% oxygen 1 hr after the insult at 2.5 atmospheres absolute (hyperbaric oxygen) or at normobaric pressure for a duration of 2 hrs.


RESULTS
During the initial period of recovery from hypoxia-ischemia, values of adenosine triphosphate and phosphocreatine remained at levels below normal, whereas the levels of glucose and other glycolytic intermediates were elevated. Hyperbaric oxygen and normobaric oxygen both attenuated brain injury, restored the levels of adenosine triphosphate and phosphocreatine, decreased the levels of the glycolytic intermediates, and increased the utilization of energy.


CONCLUSIONS
These results suggest that oxygen treatment during the initial period of recovery from a hypoxia-ischemic insult is able to attenuate energy deficits in the brain, which ultimately leads to a reduction in brain injury.
Calvert
John W
JW
Department of Physiology, Loma Linda University Medical Center, Loma Linda, CA, USA.
Zhang
John H
JH
D000227:Adenine Nucleotides / Q000378:metabolism*; D000244:Adenosine Diphosphate; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D004734:Energy Metabolism; D006003:Glycogen / Q000378:metabolism; D020925:Hypoxia-Ischemia, Brain / Q000473:pathology / Q000628:therapy*; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
D000227:Adenine Nucleotides; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006003:Glycogen