Heliox and oxygen reduce infarct volume in a rat model of focal ischemia.
Normobaric hyperoxia treatment has recently been demonstrated to be remarkably beneficial in acute focal ischemia. The present study compared hyperoxia treatment with a novel heliox treatment. Adult male rats breathed 30% oxygen and 70% nitrogen (control group), 100% oxygen (hyperoxia group), or 30% oxygen and 70% helium (heliox group) during a middle cerebral artery occlusion for 2 h and a 1-hour reperfusion (n=6 in each group). Neurological deficits were scored at 3 and 24 h post focal ischemia. Neither the physiological parameters (body temperature, blood pressure, heart rate, O(2) saturation, and laser Doppler cerebral blood) nor the 3-hour post ischemia neurological scores differed between groups. However, the neurological scores showed a statistically significant improvement at 24 h post ischemia in the heliox group (p<0.05). The infarct volume (mean+SD) as measured by 2,3,5-triphenyltetrazolium staining included 36+/-17% of the involved hemisphere in the control group, 16+/-14% in the hyperoxia group, and 4+/-2% in the heliox group (p<0.01). In conclusion, whereas hyperoxia reduced the infarct volume, heliox further reduced the infarct volume and improved 24-hour neurological deficits in a rat model of focal ischemia. This suggests that a greater benefit may accrue from heliox therapy.
Pan
Yi
Y
Department of Neurology, Saint Louis University Hospital, 3635 Vista Ave., Saint Louis, MO 63110, USA. pany@slu.edu
Zhang
Haibo
H
VanDeripe
Donald R
DR
Cruz-Flores
Salvador
S
Panneton
W Michael
WM
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D002545:Brain Ischemia / Q000473:pathology* / Q000628:therapy*; D002544:Cerebral Infarction / Q000473:pathology* / Q000628:therapy*; D002560:Cerebrovascular Circulation / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006371:Helium / Q000627:therapeutic use*; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D010100:Oxygen / Q000097:blood / Q000627:therapeutic use*; D010102:Oxygen Inhalation Therapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology
D006371:Helium; C038949:heliox; D010100:Oxygen