Temporal profile of ischemic tissue damage, neutrophil response, and vascular plugging following permanent and transient (2H) middle cerebral artery occlusion in the rat

Brain temperature is elevated in acute ischemic stroke, especially in the ischemic penumbra (IP). We attempted to investigate the dynamic evolution of brain temperature in different ischemic regions in a monkey model of middle cerebral artery occlusion. The brain temperature of different ischemic regions was measured with proton magnetic resonance spectroscopy (1H MRS), and the evolution processes of brain temperature were compared among different ischemic regions. We found that the normal (baseline) brain temperature of the monkey brain was 37.16°C. In the artery occlusion stage, the mean brain temperature of ischemic tissue was 1.16°C higher than the baseline; however, this increase was region dependent, with 1.72°C in the IP, 1.08°C in the infarct core, and 0.62°C in the oligemic region. After recanalization, the brain temperature of the infarct core showed a pattern of an initial decrease accompanied by a subsequent increase. However, the brain temperature of the IP and oligemic region showed a monotonously and slowly decreased pattern. Our study suggests thatin vivomeasurement of brain temperature could help to identify whether ischemic tissue survives.

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Regional Cerebral Blood Flow during and after 2 Hours of Middle Cerebral Artery Occlusion in the Rat

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-199710000-00008 ◽

1997 ◽

Vol 17 (10) ◽

pp. 1066-1073 ◽

Cited By ~ 59

Author(s):

Ryoichi Tsuchidate ◽

Qing-Ping He ◽

Maj-Lis Smith ◽

Bo K. Siesjö

Keyword(s):

Middle Cerebral Artery ◽

Middle Cerebral Artery Occlusion ◽

Cerebral Artery ◽

Artery Occlusion ◽

Vascular Events ◽

Recirculation Flow ◽

Ischemic Tissue ◽

Reperfusion Period ◽

Core Areas ◽

Cerebral Artery Occlusion

In this study we explored if the secondary bioenergetic failure, which occurs a few hours after recirculation, following transient middle cerebral artery occlusion (MCAO) in rats, is caused by a compromised reflow. We induced 2 hours of MCAO and measured CBF at the end of the ischemia, as well as 15 minutes, 1, 2, and 4 hours after the start of recirculation, using autoradiographic or tissue sampling 14C-iodoantipyrine techniques. After 2 hours of MCAO, the autoradiographically measured CBF in the ischemic core areas was reduced to 3 to 5% of contralateral values. The reduction in CBF was less in neighboring, penumbral areas. After recirculation, flow already normalized in core tissues after 15 minutes, and remained close to normal for the 4 hours recirculation period studied. However, in penumbral tissues, recovery CBF values were usually below normal. The results show that tissues that are heavily compromised by the 2-hour period of ischemia and are destined to incur infarction, show a “relative hyperemia” during recirculation. In fact, some areas of the previously densely ischemic tissue showed overt hyperperfusion. This finding raises the question whether the relative or absolute hyperemia reflects events that are pathogenetically important. Because drugs that clearly ameliorate the final damage incurred fail to alter the relative hyperperfusion of previously ischemic tissues, it is concluded that vascular events in the reperfusion period do not play a major role in causing the final damage.

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Evolution of Microcirculatory Disturbances after Permanent Middle Cerebral Artery Occlusion in Rats

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-199912000-00005 ◽

1999 ◽

Vol 19 (12) ◽

pp. 1322-1328 ◽

Cited By ~ 15

Author(s):

Johannes Vogel ◽

Alexander Hermes ◽

Wolfgang Kuschinsky

Keyword(s):

Middle Cerebral Artery ◽

Middle Cerebral Artery Occlusion ◽

Cerebral Artery ◽

Capillary Flow ◽

Artery Occlusion ◽

Low Flow ◽

Capillary Perfusion ◽

Ischemic Tissue ◽

Cerebral Artery Occlusion ◽

State 1

Nonischemic brain capillaries show a continuous and heterogeneous plasma perfusion. In the current study, plasma perfusion was investigated in rats during 2 to 168 hours of permanent middle cerebral artery occlusion. Perfused capillaries were detected in brain cryosections by fluorescein isothyocanate (FITC) dextran after 10 minutes of circulation time. Heterogeneity of capillary perfusion was identified by Evans blue (EB), which circulated for 3 seconds. In this setting, the heterogeneity of intracapillary EB concentrations reflects heterogeneities in capillary flow velocities. The CBF was quantified by simultaneous iodo[14C]antipyrine autoradiography. When moving from normal flow to low-flow areas in the ischemic hemisphere, three states of capillary filling could be distinguished: state 1—fast perfusion, filling by FITC dextran and EB (CBF 0.33 mL • g–1 • min–1); state 2—delayed perfusion, only FITC dextran filling (CBF 0.104 mL • g–1 • min–1); state 3— minimal perfusion, no dye filling (CBF 0.056 mL • g–1 • min−1). In tissue of state 1 at the borderline to ischemic tissue, a higher heterogeneity of intracapillary EB concentration (85.7%) was found than in the contralateral nonischemic hemisphere (76.4%) ( P < 0.05), indicating a compromised microcirculation. The adjacent ischemic areas were filled by FITC dextran (state 2) 2 to 4 hours after middle cerebral artery occlusion, indicating a maintained, although slow, perfusion at this time. Later, minimal perfused areas (state 3) progressively replaced the delayed perfused areas (state 2). This study shows, for the first time, the evolution of microvascular disturbances in relation to CBF. In the low-flow areas, an early residual plasma perfusion is later followed by a lack of perfusion or minimal perfusion. In areas of higher, although reduced flow at the border between normal and ischemic tissue, an extreme capillary perfusion heterogeneity indicates permanent microcirculatory abnormalities.

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The Temporal Profile of OPG Expression and Regulatory Role on Ischemic Brain Injury in Rats After MCAo

Medical Research ◽

10.6913/mrhk.202103_3(1).0001 ◽

2021 ◽

Vol 3 (1) ◽

pp. 1-5

Author(s):

Haijian Li ◽

Jincheng Jincheng ◽

Lin Wang ◽

Yiting Fu ◽

Chunzhen Zhao

Keyword(s):

Brain Injury ◽

Serum Level ◽

Protein Expression ◽

Middle Cerebral Artery ◽

Middle Cerebral Artery Occlusion ◽

Cerebral Artery ◽

Artery Occlusion ◽

Ischemic Brain ◽

Temporal Profile ◽

Cerebral Artery Occlusion

Objective To investigate the temporal profile of osteoprotegerin (OPG) in middle cerebral artery occlusion (MCAo) rats and the serum level of RANKL and ALP in OPG deficient and wild type rats. Methods Rats was anesthetized and subjected to MCAo by transient occlusion of middle cerebral artery occlusion. The serum level of OPG, RANKL and ALP in rats after MCAo was examined by ELISA assay. The protein expression of OPG in ischemic brain was determined by Western blot analysis. Results The level of OPG in the rat serum was significantly increased from 6 h after MCAo and peaked at 12-24 and 72-168 h. The protein expression of OPG was upregulated from 12 h after MCAo and peaked at 72 h. The level of RANKL and ALP was significantly decreased in OPG deficient rats after MCAo. Conclusion OPG/RANKL signaling is associated with brain injury after MCAo, indicating a potential therapeutic target for ischemic stroke.

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