Neuroprotective effect of hyperbaric oxygen therapy monitored by MR-imaging after embolic stroke in rats.
The potential neuroprotective effects of hyperbaric oxygen (HBO) were tested in an embolic model of focal cerebral ischemia with partially spontaneous reperfusion. Rats (n = 10) were subjected to embolic middle cerebral artery occlusion (MCAO) and diffusion weighted MRI (DWI) was performed at baseline, 1, 3, and 6 h after MCAO to determine the ADC viability threshold yielding the lesion volumes that best approximated the 2,3,5-triphenyltetrazolium chloride (TTC) infarct volumes at 24 h (experiment 1). For assessment of neuroprotective effects, rats were treated with 100% oxygen at 2.5 atmospheres absolute (ATA, n = 15) or normobaric room air (n = 15) for 60 min beginning 180 min after MCAO (experiment 2). DWI-, perfusion (PWI)- and T2-weighted MRI (T2WI) started within 0.5 h after MCAO and was continued 5 h, 24 h (PWI and T2WI only), and 168 h (T2WI only). Infarct volume was calculated based on TTC-staining at 24 h (experiment 1) or 168 h (experiment 2) post-MCAO. ADC-lesion evolution was maximal between 3 and 6 h. In experiment 2, the relative regional cerebral blood volume (rCBV) of both groups showed similar incomplete spontaneous reperfusion in the ischemic core. HBO reduced infarct volume to 145.3 +/- 39.6 mm3 vs. 202.5 +/- 58.3 mm3 (control, P = 0.029). As shown by MRI and TTC, HBO treatment demonstrated significant neuroprotection at 5 h after embolic focal cerebral ischemia that lasted for 168 h.
Henninger
Nils
N
Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01655, USA. Nils.Henninger@umassmed.edu
Küppers-Tiedt
Lea
L
Sicard
Kenneth M
KM
Günther
Albrecht
A
Schneider
Dietmar
D
Schwab
Stefan
S
D000818:Animals; D001157:Arterial Occlusive Diseases / Q000150:complications; D020520:Brain Infarction / Q000473:pathology / Q000628:therapy; D002545:Brain Ischemia / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D002539:Cerebral Arterial Diseases / Q000150:complications; D002540:Cerebral Cortex / Q000187:drug effects / Q000473:pathology; D004617:Embolism / Q000150:complications*; D006931:Hyperbaric Oxygenation; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020768:Middle Cerebral Artery / Q000473:pathology; D018696:Neuroprotective Agents / Q000627:therapeutic use; D010100:Oxygen / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D020521:Stroke / Q000209:etiology / Q000473:pathology / Q000628:therapy; D016019:Survival Analysis; D013997:Time Factors
D018696:Neuroprotective Agents; D010100:Oxygen