Previous studies have demonstrated that melatonin combined with exercise can alleviate secondary damage after spinal cord injury in rats. Therefore, it is hypothesized that melatonin combined with exercise can also al...Previous studies have demonstrated that melatonin combined with exercise can alleviate secondary damage after spinal cord injury in rats. Therefore, it is hypothesized that melatonin combined with exercise can also alleviate ischemic brain damage. In this study, adult rats were subjected to right middle cerebral artery occlusion after receiving 10 mg/kg melatonin or vehicle subcutaneously twice daily for 14 days. Forced exercise using an animal treadmill was performed at 20 m/min for 30 minutes per day for 6 days prior to middle cerebral artery occlusion. After middle cerebral artery occlusion, each rat received melatonin combined with exercise, melatonin or exercise alone equally for 7 days until sacrifice. Interestingly, rats receiving melatonin combined with exercise exhibited more severe neurological deficits than those receiving melatonin or exercise alone. Hypoxia-inducible factor la mRNA in the brain tissue was upregulated in rats receiving melatonin combined with exercise. Similarly, microtubule associated protein-2 mRNA expression was significantly upregulated in rats receiving melatonin alone. Chondroitin sulfate proteoglycan 4 （NG2） mRNA expression was significantly decreased in rats receiving melatonin combined with exercise as well as in rats receiving exercise alone. Furthermore, neural cell loss in the primary motor cortex was significantly reduced in rats receiving melatonin or exercise alone, but the change was not observed in rats receiving melatonin combined with exercise. These findings suggest that excessive intervention with melatonin, exercise or their combination may lead to negative effects on ischemia/reperfusion-induced brain damage.展开更多
Ephedrine has a protective effect against cerebral ischemia,but its side effects limit its clinical application.Results from a previous study showed that 1.5 mg/kg per day ephedrine can promote motion recovery in rats...Ephedrine has a protective effect against cerebral ischemia,but its side effects limit its clinical application.Results from a previous study showed that 1.5 mg/kg per day ephedrine can promote motion recovery in rats following cerebral ischemia/reperfusion without significant side effects.In the present study,ephedrine at doses of 3.0,2.5 and 2.0 mg/kg was used to treat rats with cerebral ischemia/reperfusion and the effects of ephedrine on the heart,liver,kidney and cerebrum were observed.Results showed that the blood pressure of rats with cerebral ischemia/reperfusion injury following ephedrine treatment was lower than in rats that recovered naturally from cerebral ischemia/reperfusion,but the pressure decreased with increasing doses of ephedrine.In addition,serum aspartate transaminase,alkaline phosphatase and creatinine concentration in rats with cerebral ischemia/reperfusion injury following ephedrine treatment were greater than in rats that recovered naturally from cerebral ischemia/reperfusion.The concentrations of these enzymes were decreased with increasing doses of ephedrine.Ephedrine-treated rats displayed hyperemia,degeneration and edema in the cerebrum,liver,heart and kidney.Results demonstrated that ephedrine exhibited side effects on the cerebrum,heart,liver and kidney in rats following cerebral ischemia/reperfusion in a dose-dependent manner.展开更多
基金funded by the KRIBB Research Initiative Program,No.KGM0321112 to Y.HongBioGreen 21 Program,No.20110301-061-542-03-00 to Y.Hong,Rural Development Administration,Republic of Korea
文摘Previous studies have demonstrated that melatonin combined with exercise can alleviate secondary damage after spinal cord injury in rats. Therefore, it is hypothesized that melatonin combined with exercise can also alleviate ischemic brain damage. In this study, adult rats were subjected to right middle cerebral artery occlusion after receiving 10 mg/kg melatonin or vehicle subcutaneously twice daily for 14 days. Forced exercise using an animal treadmill was performed at 20 m/min for 30 minutes per day for 6 days prior to middle cerebral artery occlusion. After middle cerebral artery occlusion, each rat received melatonin combined with exercise, melatonin or exercise alone equally for 7 days until sacrifice. Interestingly, rats receiving melatonin combined with exercise exhibited more severe neurological deficits than those receiving melatonin or exercise alone. Hypoxia-inducible factor la mRNA in the brain tissue was upregulated in rats receiving melatonin combined with exercise. Similarly, microtubule associated protein-2 mRNA expression was significantly upregulated in rats receiving melatonin alone. Chondroitin sulfate proteoglycan 4 （NG2） mRNA expression was significantly decreased in rats receiving melatonin combined with exercise as well as in rats receiving exercise alone. Furthermore, neural cell loss in the primary motor cortex was significantly reduced in rats receiving melatonin or exercise alone, but the change was not observed in rats receiving melatonin combined with exercise. These findings suggest that excessive intervention with melatonin, exercise or their combination may lead to negative effects on ischemia/reperfusion-induced brain damage.
文摘Ephedrine has a protective effect against cerebral ischemia,but its side effects limit its clinical application.Results from a previous study showed that 1.5 mg/kg per day ephedrine can promote motion recovery in rats following cerebral ischemia/reperfusion without significant side effects.In the present study,ephedrine at doses of 3.0,2.5 and 2.0 mg/kg was used to treat rats with cerebral ischemia/reperfusion and the effects of ephedrine on the heart,liver,kidney and cerebrum were observed.Results showed that the blood pressure of rats with cerebral ischemia/reperfusion injury following ephedrine treatment was lower than in rats that recovered naturally from cerebral ischemia/reperfusion,but the pressure decreased with increasing doses of ephedrine.In addition,serum aspartate transaminase,alkaline phosphatase and creatinine concentration in rats with cerebral ischemia/reperfusion injury following ephedrine treatment were greater than in rats that recovered naturally from cerebral ischemia/reperfusion.The concentrations of these enzymes were decreased with increasing doses of ephedrine.Ephedrine-treated rats displayed hyperemia,degeneration and edema in the cerebrum,liver,heart and kidney.Results demonstrated that ephedrine exhibited side effects on the cerebrum,heart,liver and kidney in rats following cerebral ischemia/reperfusion in a dose-dependent manner.
