scholarly journals Transient Middle Cerebral Artery Occlusion by Intraluminal Suture: II. Neurological Deficits, and Pixel-Based Correlation of Histopathology with Local Blood Flow and Glucose Utilization

1997 ◽  
Vol 17 (12) ◽  
pp. 1281-1290 ◽  
Author(s):  
Weizhao Zhao ◽  
Ludmila Belayev ◽  
Myron D. Ginsberg

We conducted a pixel-based analysis of the acute hemodynamic and metabolic determinants of infarctive histopathology in a reproducible model of temporary (2-hour) middle cerebral artery occlusion (MCAO) produced in rats by an intraluminal suture. Three-dimensional averaged image data sets of local cerebral blood flow (LCBF) and glucose utilization (LCMRglc) acquired in the companion study ( Belayev et al., 1997 ) either at the end of a 2-hour period of MCAO or after 1 hour of recirculation were comapped (using digitized atlas-templates) with data sets depicting the frequency of histological infarction in a matched animal group (n = 8) in which 2 hours of MCAO was followed by 3-day survival, sequential neurobehavioral examinations, and perfusion-fixation and paraffin-embedding of brains for light-microscopic analysis. All rats developed marked postural-reflex and forelimb-placing deficits at 60 minutes of MCAO, signifying high-grade ischemia. Tactile placing deficits persisted during the 72-hour observation period while visual placing and postural-reflex abnormalities variably improved. Comapping of LCBF and histopathology showed that in those pixels destined to undergo infarction, LCBF measured at 2 hours of MCAO showed a sharp distributional peak centered at 0.14 mL/g/min. In 70% of pixels destined to infarct, LCBF at 2 hours of MCAO was 0.24 mL/g/min or below, and in 89% LCBF was below 0.47 mL/g/min (the upper limits of the ischemic core and penumbra, respectively, as defined in the companion study [ Belayev et al., 1997 ]). Local cerebral glucose utilization measured at ~1 hour after 2 hours of MCAO was distributed bimodally in the previously ischemic hemisphere. The major peak, at 22 μmol/100 g/min, coincided exactly with the distribution peak of pixels destined to undergo infarction, while in pixels with a zero probability of infarction, LCMRglc was higher by 12 to 13 μmol/100 g/min. These results indicate that local blood flow at 2 hours of MCAO is a robust predictor of eventual infarction. Pixels with ischemic-core levels of LCBF (0% to 20% of control) have a 96% probability of infarction, while the fate of the penumbra is more heterogeneous: below LCBF of 0.35 mL/g/min, the probability of infarction is 92%, while approximately 20% pixels in the upper-penumbral LCBF range (30% to 40% of control) escape infarction. Our data strongly support the view that the likelihood of infarction within the ischemic penumbra is highly influenced by very subtle differences in early perfusion.

1997 ◽  
Vol 17 (12) ◽  
pp. 1266-1280 ◽  
Author(s):  
Ludmila Belayev ◽  
Weizhao Zhao ◽  
Raul Busto ◽  
Myron D. Ginsberg

Using autoradiographic image-averaging strategies, we studied the relationship between local glucose utilization (LCMRglc) and blood flow (LCBF) in a highly reproducible model of transient (2-hour) middle cerebral artery occlusion (MCAO) produced in Sprague-Dawley rats by insertion of an intraluminal suture coated with poly-L-lysine. Neurobehavioral examination at 60 minutes after occlusion substantiated a high-grade deficit in all animals. In two subgroups, LCBF was measured with 14C-iodoantipyrine at either 1.5 hours of MCAO, or at 1 hour of recirculation after suture removal. In two other matched subgroups, LCMRglc was measured with 14C-2-deoxyglucose at 1.5 to 2.25 hours of MCAO, and at 0.75 to 1.5 hours of recirculation after 2 hours of MCAO. Average image data sets were generated for LCBF, LCMRglc, and the LCMRglc/LCBF ratio for each study time. Middle cerebral artery occlusion for 2 hours induced graded LCBF decrements affecting ipsilateral cortical and basal ganglionic regions. After 1 hour of recirculation, LCBF in previously ischemic neocortical regions increased by 40% to 200% above ischemic levels, but remained depressed, on average, at about 40% of control. By contrast, frank hyperemia was noted in the previously ischemic caudoputamen. Mean cortical LCBF values during MCAO correlated highly with their respective LCBF values after 1 hour of recirculation (R = 0.93), suggesting that postischemic LCBF recovery is related to the depth of ischemia. Despite focal ischemia, LCMRglc during ~2 hours of MCAO was preserved, on average, at near-normal levels; but following ~1 h of recirculation, LCMRglc became markedly depressed (on average, 55% of control in previously densely ischemic cortical regions). Regression analysis indicated that this depressed glucose utilization was determined largely by the intensity of antecedent ischemia. By pixel analysis, the ischemic core (defined as LCBF 0% to 20% of control) comprised 33% of the ischemic hemisphere, and the penumbra (LCBF 20% to 40%) accounted for 26%. The penumbra was concentrated at the coronal poles of the ischemic lesion and formed a thin shell around the central ischemic core. During 2 hours of MCAO, the LCMRglc/LCBF ratio within the ischemic penumbra was increased four-fold above normal (average, 179 umol/100 mL). In marked contrast, after ~1 h recirculation, this uncoupling had almost completely subsided. The companion study ( Zhao et al., 1997 ) further analyzes these findings in relation to patterns of infarctive histopathology.


Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 353-353
Author(s):  
Yitao Liu ◽  
Ludmila Belayev ◽  
Weizhao Zhao ◽  
Raul Busto ◽  
Isabel Saul ◽  
...  

P79 Bone morphogenetic protein-7 (BMP-7) (=osteogenic protein-1, OP-1) has been shown to enhance dendritic growth and improve functional recovery after experimental stroke. In this study, we examined the effect of BMP-7 on local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCMRglu) following transient middle cerebral artery occlusion. Sprague Dawley rats (n=29) were anesthetized with halothane/nitrous oxide and received 2-h middle cerebral artery occlusion (MCAo) by poly-L-lysine coated intraluminal suture (1). Rectal and cranial (left temporalis muscle) temperatures were regulated at 37–37.5 o C. BMP-7 or vehicle (volume, 25μl) was administered intracisternally in blinded fashion at 24h after MCAo. Neurological status was evaluated during occlusion (60 min) and daily for 2 days after MCAo; a grading scale of 0–12 was employed (1). LCMRglu was measured autoradiographically with 14 C-2 deoxyglucose (2-DG) and LCBF with 14 C-iodoantipyrine 48 h after MCAo. Four animals groups were studied: LCMRglu series (BMP-7, n=7; vehicle, n=8); LCBF series (BMP-7, n=6; vehicle, n=8). Average three-dimensional image data sets were constructed for each group and were compared by pixel-based statistical methods (2). Rectal and cranial temperatures, MABP, plasma glucose and blood gases were similar among groups. BMP-7 significantly improved the neurological score compared to vehicle at 48 after MCAo (7.3 ± 0.4 vs. 9.0 ± 0.2, respectively; p<0.0003). Compared to vehicle-rats, BMP-7 significantly increased LCMRglu in ipsilateral basal ganglia, improved LCBF in ipsilateral subthalamus, and decreased LCBF and LCMRglu in contralateral cortical regions. The improved glucose metabolism in ipsilateral basal ganglia of BMP-7 rats is compatible with its salutary influence on neurological recovery. Supported by Creative BioMolecules, Inc., Hopkinton, MA, and by NIH Grant NS 05820. (1)Belayev L, Alonso OF, Busto R, Zhao W, Ginsberg MD: Stroke 27:1616–1623,1996. (2)Zhao W, Belayev L, Ginsberg MD: J Cereb Blood Flow Metab 17:1281–1290,1997.


1989 ◽  
Vol 257 (5) ◽  
pp. H1656-H1662
Author(s):  
M. Anwar ◽  
H. R. Weiss

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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