MRI Analysis of the Changes in Apparent Water Diffusion Coefficient, T2 Relaxation Time, and Cerebral Blood Flow and Volume in the Temporal Evolution of Cerebral Infarction Following Permanent Middle Cerebral Artery Occlusion in Rats

The effects of adenosine on regional cerebral blood flow and indexes of the total and perfused microvascular bed were studied after 1 h of middle cerebral artery occlusion in the anesthetized rat. Iodo[14C]antipyrine was used to determine cerebral blood flow. Fluorescein isothiocyanate-dextran was used to study the perfused microvasculature, and an alkaline phosphatase stain was used to identify the total bed. Mean arterial blood pressure was significantly reduced by adenosine. Cerebral blood flow increased significantly by 75%, except in the flow-restricted cortex where flow averaged 28 +/- 15 (SD) ml.min-1.100 g-1 in control and 34 +/- 33 ml.min-1.100 g-1 in adenosine-treated animals. No significant regional structural differences were observed within the microvascular beds of the two groups. The percentage of the microvascular volume perfused increased significantly in all brain regions in the adenosine-treated rats, including the flow-restricted cortex. The percent perfused arteriolar volume in the flow-restricted cortex was 30 +/- 12% in control and 95 +/- 3% in adenosine-treated animals. Similar values for the capillary bed were 22 +/- 10% in control and 54 +/- 3% in adenosine-treated rats. These results indicate a maintenance of flow with a reduction in diffusion distances in the flow-restricted cortex after treatment with adenosine.

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Changes of relaxation times (T1, T2) and apparent diffusion coefficient after permanent middle cerebral artery occlusion in the rat: temporal evolution, regional extent, and comparison with histology

Magnetic Resonance in Medicine ◽

10.1002/mrm.1910340607 ◽

1995 ◽

Vol 34 (6) ◽

pp. 824-834 ◽

Cited By ~ 151

Author(s):

Mathias Hoehn-berlar ◽

Manfred Eis ◽

Tobias Back ◽

Kanehisa Kohno ◽

Katsuhiro Yamashita

Keyword(s):

Diffusion Coefficient ◽

Apparent Diffusion Coefficient ◽

Middle Cerebral Artery ◽

Middle Cerebral Artery Occlusion ◽

Cerebral Artery ◽

Temporal Evolution ◽

Relaxation Times ◽

Artery Occlusion ◽

Apparent Diffusion ◽

Cerebral Artery Occlusion

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Investigation of Estrogen Status and Increased Stroke Sensitivity on Cerebral Blood Flow after a Focal Ischemic Insult

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-200006000-00005 ◽

2000 ◽

Vol 20 (6) ◽

pp. 931-936 ◽

Cited By ~ 38

Author(s):

Hilary V. O. Carswell ◽

Niall H. Anderson ◽

James J. Morton ◽

James McCulloch ◽

Anna F. Dominiczak ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Internal Control ◽

Artery Occlusion ◽

Cumulative Distribution ◽

Distribution Analysis ◽

Spontaneously Hypertensive ◽

Endogenous Estrogen ◽

Wistar Kyoto ◽

Cerebral Artery Occlusion

Recently the authors have shown that female stroke-prone spontaneously hypertensive rats (SHRSPs) in proestrus (high endogenous estrogen), sustain more than 20% smaller infarcts after middle cerebral artery occlusion (MCAO) compared with SHRSPs in metestrus (low endogenous estrogen). Because estrogen has vasodilator properties, the authors investigated whether the estrous state influences cerebral blood flow (CBF) after MCAO. CBF was measured 2.5 hours after a distal MCAO by [14C]iodo-antipyrine autoradiography in conscious SHRSPs either in metestrus or in proestrus. There were no significant differences in CBF when analyzed either at predetermined anatomic regions or by cumulative distribution analysis of areas with flow <25 mL/100 g/min. As a positive internal control, the authors compared results in SHRSPs with those in their normotensive reference strain, Wistar Kyoto rat. SHRSPs displayed more severe and widespread ischemia than Wistar Kyoto rats. Thus, the absence of demonstrable CBF differences between estrous states appears to be unrelated to the CBF measurement paradigm. In conclusion, the smaller infarct size afforded in proestrus in SHRSPs is unlikely to be due to an influence on CBF.

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