| Title: |
N-Acetylaspartate Distribution in Rat Brain Striatum During Acute Brain Ischemia |
| Authors: |
Sager, Thomas Nikolaj; Laursen, Henning; Fink-Jensen, Anders; Topp, Simon; Stensgaard, Anders; Hedehus, Maj; Rosenbaum, Sverre; Valsborg, Jacob Stenmann; Hansen, Anker Jon |
| Source: |
Journal of Cerebral Blood Flow & Metabolism ; volume 19, issue 2, page 164-172 ; ISSN 0271-678X 1559-7016 |
| Publisher Information: |
SAGE Publications |
| Publication Year: |
1999 |
| Description: |
Brain N-acetylaspartate (NAA) can be quantified by in vivo proton magnetic resonance spectroscopy ( 1 H-MRS) and is used in clinical settings as a marker of neuronal density. It is, however, uncertain whether the change in brain NAA content in acute stroke is reliably measured by 1 H-MRS and how NAA is distributed within the ischemic area. Rats were exposed to middle cerebral artery occlusion. Preischemic values of [NAA] in striatum were 11 mmol/L by 1 H-MRS and 8 mmol/kg by HPLC. The methods showed a comparable reduction during the 8 hours of ischemia. The interstitial level of [NAA] ([NAA] e ) was determined by microdialysis using [ 3 H]NAA to assess in vivo recovery. After induction of ischemia, [NAA] e increased linearly from 70 µmol/L to a peak level of 2 mmol/L after 2 to 3 hours before declining to 0.7 mmol/L at 7 hours. For comparison, [NAA] e was measured in striatum during global ischemia, revealing that [NAA] e increased linearly to 4 mmol/L after 3 hours and this level was maintained for the next 4 h. From the change in in vivo recovery of the interstitial space volume marker [ 14 C]mannitol, the relative amount of NAA distributed in the interstitial space was calculated to be 0.2% of the total brain NAA during normal conditions and only 2 to 6% during ischemia. It was concluded that the majority of brain NAA is intracellularly located during ischemia despite large increases of interstitial [NAA]. Thus, MR quantification of NAA during acute ischemia reflects primarily changes in intracellular levels of NAA. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1097/00004647-199902000-00008 |
| Availability: |
https://doi.org/10.1097/00004647-199902000-00008; https://journals.sagepub.com/doi/pdf/10.1097/00004647-199902000-00008; https://journals.sagepub.com/doi/full-xml/10.1097/00004647-199902000-00008 |
| Rights: |
https://journals.sagepub.com/page/policies/text-and-data-mining-license |
| Accession Number: |
edsbas.BE619CD8 |
| Database: |
BASE |