title: Immediate or delayed mild hypothermia prevents focal cerebral infarction.
abstract: The protective effect of mild hypothermia was studied in rodent models of both permanent and transient focal cerebral ischemia. In Expt. 1, Wistar rats were exposed to 6 h permanent ischemia by bilateral occlusion of both common carotid arteries and right middle cerebral artery. In Expt. 2, animals were exposed to 3 h transient ischemia followed by 21 h reperfusion, and in Expt. 3, 3 h transient ischemia was followed by 69 h of reperfusion. Expt. 4 used 3 h transient ischemia followed by 3 h reperfusion. In Expt. 1, animals maintained at 37 degrees C rectal (normothermia) suffered a mean infarct volume (+/- S.D.) of 142 +/- 44 mm3 (n = 6), which was reduced for those exposed to permanent hypothermic (32 degrees C) ischemia to 56 +/- 64 mm3 (n = 10) (P less than 0.05). In Expt. 2, normothermic ischemia and reperfusion resulted in an infarction of 211 +/- 35 mm3 (n = 6). Intra-ischemic hypothermia (32 degrees C) followed by 21 h of normothermic reperfusion resulted in 17 +/- 12 mm3 of infarction (n = 9) (P less than 0.001). Hypothermia for either the first or second 1.5 h of the 3 h ischemic insult reduced the infarct volume to 116 +/- 76 mm3 (n = 6) (P less than 0.05) or 108 +/- 73 mm3 (n = 7) (P less than 0.01), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Neurology-Neuroscience Department, University of Ottawa, Ottawa Civic Hospital, Ont., Canada.
authors.forename: D
authors.initials: D
authors.lastname: Xue
authors.forename: Z G
authors.initials: ZG
authors.lastname: Huang
authors.forename: K E
authors.initials: KE
authors.lastname: Smith
authors.forename: A M
authors.initials: AM
authors.lastname: Buchan
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology; D002545:Brain Ischemia / Q000503:physiopathology; D002544:Cerebral Infarction / Q000503:physiopathology / Q000517:prevention & control*; D002560:Cerebrovascular Circulation / Q000502:physiology; D007036:Hypothermia, Induced; D002546:Ischemic Attack, Transient / Q000503:physiopathology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D015424:Reperfusion