1. Effects of detraining on preconditioning exercise-induced neuroprotective potential after ischemic stroke in rats
- Author
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Ikuro Maruyama, Akira Tani, Kosuke Norimatsu, Shotaro Otsuka, Seiya Takada, Kazuki Nakanishi, Harutoshi Sakakima, and Hiroshi Maejima
- Subjects
medicine.medical_specialty ,Histology ,Neurology ,Neuroprotection ,050105 experimental psychology ,Rats, Sprague-Dawley ,03 medical and health sciences ,0302 clinical medicine ,Neurotrophic factors ,Internal medicine ,Animals ,Medicine ,Aerobic exercise ,0501 psychology and cognitive sciences ,Treadmill ,Stroke ,Ischemic Stroke ,Glial fibrillary acidic protein ,biology ,business.industry ,Brain-Derived Neurotrophic Factor ,General Neuroscience ,05 social sciences ,Infarction, Middle Cerebral Artery ,medicine.disease ,Rats ,Disease Models, Animal ,Endocrinology ,Apoptosis ,biology.protein ,Anatomy ,business ,030217 neurology & neurosurgery - Abstract
Preconditioning exercise prior to stroke exerts neuroprotection, which is an endogenous strategy that leads the brain cells to express several intrinsic factors and inhibits their apoptosis. However, it is unclear how long these benefits last after exercise cessation. The aim of this study was to investigate the effects of detraining on preconditioning exercise-induced neuroprotective potential after stroke. Rats were trained using a treadmill for aerobic exercise 5 days each week for 3 weeks, and their neuroprotective effects were examined until 3 weeks after exercise cessation. Stroke was induced by 60 min of left middle cerebral artery occlusion at 3 days, 1, 2, and 3 weeks after exercise cessation. Infarct volume, neurological deficits, sensorimotor function, expression levels of brain-derived neurotrophic factor (BDNF), hypoxia-induced factor-1α (HIF-1α), glial fibrillary acidic protein (GFAP), and P2X7 receptors, and apoptosis activity were examined using immunohistochemical and western blot analyses. Preconditioning exercise significantly reduced infarct volume and ameliorated sensorimotor function after stroke, and its beneficial effects were observed until 2 weeks after exercise cessation. The expression level of BDNF in the ischemic brain was significantly upregulated at 3 days after exercise cessation; however, the expression levels of HIF-1α, GFAP, and P2X7 receptor were significantly increased until 2 weeks after exercise cessation; thereby, significant anti-apoptotic effects were lost at 3 weeks of detraining. Our findings suggest that preconditioning exercise-induced neuroprotective potential may be lost shortly after exercise cessation. Neuroprotection through intrinsic protective factors, such as BDNF and HIF-1α, may provide different neuroprotective mechanisms in a time-dependent manner during detraining.
- Published
- 2021
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