Mild hypothermia has no long-term impact on postischemic neurogenesis in rats.

Full Abstract

BACKGROUND: Postischemic improvement of functional outcome by therapeutic hypothermia may be related to cerebral regeneration by postischemic neurogenesis. We investigated whether mild peri-ischemic hypothermia leads to a long-term increase in postischemic neurogenesis. METHODS: Seventy male sevoflurane-anesthetized Sprague Dawley rats were randomly assigned to the following treatment groups: normothermic ischemia, intraischemic hypothermia, and postischemic hypothermia with corresponding sham-operated controls. Fifteen naïve rats were investigated as reference for natural neurogenesis. Forebrain ischemia was induced by bilateral common carotid artery occlusion and hemorrhagic hypotension. In normothermic groups, the pericranial temperature was maintained at 37.5 degrees C. Animals in the hypothermic groups were cooled to a pericranial temperature of 33 degrees C for 45 min. All animals received 5-bromo-2-deoxyuridine for 7 days. Histopathological damage and 5-bromo-2-deoxyuridine-positive neurons of the hippocampus were analyzed after 28 days. RESULTS: Hypothermia had no impact on natural neurogenesis. Cerebral ischemia increased the number of new neurons regardless of pericranial temperature. Forty-five minutes of hypothermia beginning before ischemia diminished hippocampal injury to <10% in the CA1 and CA3 regions, whereas 45 min of postischemic hypothermia beginning after reperfusion did not reduce neuronal injury compared with normothermia. CONCLUSIONS: Neither intraischemic nor postischemic hypothermia affected the ischemia-induced increase in endogenous neurogenesis. Intraischemic hypothermia reduced hippocampal damage, whereas postischemic hypothermia as applied here did not prevent formation of histopathological injury. This indicates that, 28 days after cerebral ischemia, postischemic neurogenesis is not significantly increased by mild peri-ischemic hypothermia and not affected by the severity of histopathological damage.

Author information

Author/s: Lasarzik, Irina (I); Winkelheide, Uta (U); Thal, Serge C (SC); Benz, Natascha (N); Lörscher, Matthias (M); Jahn-Eimermacher, Antje (A); Werner, Christian (C); Engelhard, Kristin (K);

Affiliation: Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Mainz, Germany. lasarzik(-atsign-)uni-mainz.d

Journal and publication information

Publication Type: Journal Article

Journal: Anesthesia and analgesia (Anesth Analg), published in United States. (Language: eng)

Reference: 2009-Nov; vol 109 (issue 5) : pp 1632-9

Dates: Created 2009/10/21; Completed 2009/11/05;

PMID: 19843801, status: MEDLINE (last retrieval date: 11/5/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.