Persistent cerebrovascular damage after stroke in type two diabetic rats measured by magnetic resonance imaging
Guangliang Ding1, Tao Yan1, Jieli Chen1
1From the Department of Neurology, Henry Ford Hospital, Detroit, MI (G.D., T.Y., J.C., M.C., L.L., Q.L., C.C., R.N., Q.J.); and Department of Physics, Oakland University, Rochester, MI (M.C.).
Background And Purpose:
Diabetes mellitus is a disease with vascular components. Consequently, the blood-brain barrier disruption after stroke may differ between diabetic and nondiabetic animals. However, few studies have documented the longitudinal blood-brain barrier disruption afte stroke in diabetic animals. In this study, using MRI, we noninvasively evaluated the blood-brain barrier damage after middle cerebral artery occlusion in diabetic and nondiabetic rats.
Methods:
Type 2 diabetes mellitus (T2DM) was induced in adult male Wistar rats by administration of a high-fat diet in combination with a single intraperitoneal injection (35 mg/kg) of streptozotocin. T2DM rats (n=9) and nondiabetic wild-type (WT) rats (n=9) were subjected to middle cerebral artery occlusion for 2 hours using the filament model. MRI was performed 1 day and then weekly for 5 weeks after middle cerebral artery occlusion for all rats.
Results:
The ischemic lesion volumes after stroke as measured using T2 maps were not significantly different between the T2DM and WT rats. Compared with the WT rats, the volumes of blood-brain barrier disruption evaluated using contrast-enhanced T1-weighted imaging with gadolinium-diethylenetriamine penta-acetic acid and the cerebral hemorrhagic volumes measured with susceptibility-weighted imaging were significantly (P<0.05) larger in the T2DM rats from 1 to 5 weeks after stroke; values of diffusion fractional anisotropy were significantly lower in T2DM rats (P<0.03) than in WT rats after stroke. These MRI measurements were consistent with histological data.
Conclusions:
Using MRI, T2-weighted imaging did not detect significant differences of the ischemic lesion volumes between T2DM and WT rats. In contrast to the WT rats, however, contrast-enhanced T1-weighted imaging and susceptibility-weighted imaging identified much more severe ischemic vascular damage, whereas fractional anisotropy demonstrated lower axonal density in the T2DM rats after stroke.
Insights
Diabetic rats showed significantly more blood-brain barrier damage and lower axonal density after stroke compared to nondiabetic rats. MRI revealed this increased vascular damage and neuronal injury over five weeks.
Area of Science:
- Neuroscience
- Vascular Biology
- Medical Imaging
Background:
- Diabetes mellitus is a systemic disease with significant vascular implications.
- Stroke-induced blood-brain barrier (BBB) disruption may be exacerbated in diabetic individuals.
- Longitudinal studies on BBB changes post-stroke in diabetes are limited.
Purpose of the Study:
- To noninvasively evaluate and compare longitudinal BBB disruption after stroke in diabetic and nondiabetic rats using Magnetic Resonance Imaging (MRI).
- To investigate the impact of Type 2 Diabetes Mellitus (T2DM) on stroke outcomes, specifically BBB integrity and lesion development.
Main Methods:
- Type 2 Diabetes Mellitus (T2DM) induced in Wistar rats via high-fat diet and streptozotocin.
- Middle Cerebral Artery Occlusion (MCAO) performed on T2DM and nondiabetic wild-type (WT) rats.
- Longitudinal MRI scans (T2 maps, contrast-enhanced T1-weighted, susceptibility-weighted imaging, diffusion fractional anisotropy) conducted weekly for 5 weeks post-MCAO.
Main Results:
- Ischemic lesion volumes (T2 maps) did not differ significantly between T2DM and WT rats.
- T2DM rats exhibited significantly larger volumes of BBB disruption (contrast-enhanced T1-weighted) and cerebral hemorrhage (susceptibility-weighted imaging) from 1 to 5 weeks post-stroke (P<0.05).
- Diffusion fractional anisotropy values were significantly lower in T2DM rats, indicating reduced axonal density (P<0.03).
Conclusions:
- Standard T2-weighted MRI did not reveal differences in ischemic lesion volume between diabetic and nondiabetic rats post-stroke.
- Advanced MRI techniques (contrast-enhanced T1-weighted and susceptibility-weighted imaging) demonstrated significantly greater ischemic vascular damage in diabetic rats.
- Fractional anisotropy measurements indicated lower axonal density in diabetic rats, suggesting more severe neuronal injury following stroke.
More Related Videos
13:50Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat
Published on: February 5, 2011
10:31Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG
Published on: December 28, 2014