Related Experiment Videos
Local hemodynamic changes during transient middle cerebral artery occlusion and recirculation in the rat: a
1Department of Neurology (D4-5), University of Miami School of Medicine, FL 33101, USA.
Abstract:
We evaluated acute alterations of local cerebral perfusion following 30 min of transient right proximal middle cerebral artery (MCA) clip-occlusion in the rat and following two intervals of postischemic reperfusion. Local cerebral blood flow (lCBF) was assessed by [14C]iodoantipyrine autoradiography. Brain temperature was controlled at 35.5-36.5 degrees C throughout the experiment. We measured lCBF in four groups of rats: (a) sham-operated controls (n = 5), (b) following 30 min MCA occlusion (n = 5), (c) following 30 min of MCA occlusion with 15-min reperfusion (n = 6) and (d) following 30 min of MCA with 120-min reperfusion (n = 6). lCBF was measured in seven regions of the ischemic and non-ischemic hemispheres. MCA occlusion induced an ipsilateral reduction of lCBF, which was most severe in the parietal cortex (8.4 +/- 4.0% of control, mean +/- S.D.), and dorsolateral caudoputamen (20.0 +/- 13.4% of control). lCBF in the non-ischemic hemisphere and in ipsilateral regions lying outside the MCA territory also decreased significantly. lCBF recovery was incomplete when assessed following only 15 min of reperfusion. Reperfusion of 120 min led to return of cortical CBF to control levels, but lCBF in the caudoputamen remained depressed (50-55% of control values). Caudoputaminal CBF and cortical CBF values were highly correlated with one another under normal and ischemic conditions, but this correlation was disrupted following reperfusion. On the basis of these results, we speculate that, if a means were found to enhance the early recovery of lCBF following transient ischemia, this might expand the therapeutic window of opportunity for the institution of other neuroprotective strategies.
Insights
Transient middle cerebral artery (MCA) occlusion severely reduced local cerebral blood flow (lCBF) in rats. Early reperfusion improved cortical blood flow, but caudoputamen flow remained low, suggesting potential for enhanced neuroprotection strategies.
Area of Science:
- Neuroscience
- Cerebrovascular Research
- Ischemia-Reperfusion Studies
Background:
- Transient focal cerebral ischemia, such as middle cerebral artery (MCA) occlusion, is a critical condition affecting brain perfusion.
- Understanding the dynamics of local cerebral blood flow (lCBF) during and after ischemia is crucial for developing effective neuroprotective strategies.
Purpose of the Study:
- To investigate the acute changes in local cerebral perfusion following transient middle cerebral artery (MCA) occlusion and subsequent reperfusion in a rat model.
- To assess the impact of different reperfusion durations (15 minutes and 120 minutes) on lCBF recovery in various brain regions.
Main Methods:
- Utilized a rat model with transient right proximal middle cerebral artery (MCA) clip-occlusion for 30 minutes.
- Assessed local cerebral blood flow (lCBF) using [14C]iodoantipyrine autoradiography.
- Measured lCBF in sham-operated controls and in groups subjected to occlusion alone, occlusion with 15-minute reperfusion, and occlusion with 120-minute reperfusion, controlling brain temperature.
Main Results:
- MCA occlusion caused a significant ipsilateral reduction in lCBF, most pronounced in the parietal cortex and dorsolateral caudoputamen.
- lCBF in the non-ischemic hemisphere and areas outside the MCA territory also decreased.
- Fifteen minutes of reperfusion resulted in incomplete lCBF recovery, while 120 minutes restored cortical CBF to control levels, but caudoputamen lCBF remained depressed (50-55% of control).
- The correlation between caudoputaminal and cortical CBF, present under normal and ischemic conditions, was disrupted after reperfusion.
Conclusions:
- Early reperfusion following transient MCA occlusion shows incomplete recovery of local cerebral blood flow, particularly in the caudoputamen.
- The disruption of the correlation between cortical and subcortical blood flow post-reperfusion highlights regional vulnerability.
- Enhancing early lCBF recovery after transient ischemia may broaden the therapeutic window for neuroprotective interventions.