Mild to moderate early exercise promotes recovery from cerebral ischemia in rats.
OBJECTIVE
We examined the effects of various exercise intensities on recovery from middle cerebral artery occlusion (MCAO) in rats.


METHODS
First, we administered a 120-minute left MCAO to male Sprague-Dawley rats and randomly assigned them to one of four groups: no exercise (Group 1), mild exercise (Group 2), moderate exercise (Group 3), and severe exercise (Group 4). Then, we trained the rats for 30 min per day for one week or two weeks. We used a five-point neurological evaluation scale to measure neurological deficits 1-day, 4-days, 7-days, 10-days and 14-days after MCAO and measured infarct volume by use of 2% 2,3,4-triphenyltetrazolium chloride in exercised brains. We also performed immunohistochemistry analysis of the brain to observe reactive astrocytosis at the peri-infarct region.


RESULTS
Neurological examination indicated that Group 2 and 3 recovered better than Group 1 after one week and two weeks (p < 0.05). Moreover, Group 2 and 3 had reduced brain infarct volume compared with Group 1 after one week (p < 0.05). There were no significant differences between Group 4 and Group 1. The thickness of the peri-infarct astrocytosis was significantly reduced in Group 4 relative to Group 1 after one week. There was a significant negative correlation between the extent of reactive astrocytosis and neurological recovery (r = -0.648, p < 0.01).


CONCLUSIONS
This study demonstrates that mild to moderate exercise that begins soon after induced cerebral ischemia promotes recovery and that astrocytes may have an important role in the recovery process.
Lee
Shi-Uk
SU
Department of Rehabilitation Medicine, Seoul National University Boramae Hospital, Sindaebang-Dong, Dongjak-Gu, Seoul.
Kim
Dae-Yul
DY
Park
Sung-Hye
SH
Choi
Deok-Hyung
DH
Park
Hee-Won
HW
Han
Tai Ryoon
TR
D000818:Animals; D020520:Brain Infarction / Q000534:rehabilitation; D004195:Disease Models, Animal; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D020244:Infarction, Middle Cerebral Artery / Q000503:physiopathology* / Q000534:rehabilitation*; D008297:Male; D009460:Neurologic Examination; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013997:Time Factors
D005904:Glial Fibrillary Acidic Protein; D010751:Phosphopyruvate Hydratase