Brain Glycogen Decreases During Intense Exercise Without Hypoglycemia: The Possible Involvement of Serotonin
Brain Glycogen Decreases During Intense Exercise Without Hypoglycemia: The Possible Involvement of Serotonin
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DOI：
10.1007/s11064-015-1594-1
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发表时间：
2015-06
影响因子：
4.4
通讯作者：
T. Matsui;Shingo Soya;K. Kawanaka;H. Soya
中科院分区：
文献类型：
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作者：
T. Matsui;Shingo Soya;K. Kawanaka;H. Soya
储存在星形胶质细胞中的脑糖原，作为神经元能量来源的乳酸来源，在低血糖的长时间运动期间减少。然而，在无低血糖的运动过程中的脑糖原动力学仍然未知。由于剧烈运动增加脑去甲肾上腺素和血清素作为已知的脑糖原分解的诱导剂，我们假设，脑糖原减少与剧烈运动不伴有低血糖。为了验证这一假设，我们采用了一个完善的急性剧烈运动模型的大鼠游泳。大鼠游泳14个20 s的回合，体重等于其体重的8%，并使用高功率（10 kW）微波辐射杀死脑酶，以准确检测脑糖原和单胺。剧烈运动不会改变血糖，但会增加血乳酸水平。运动后，海马、小脑、皮质和脑干的脑糖原减少，脑乳酸增加。同时，海马和脑干中的5-羟色胺周转相互增加，并与脑糖原减少有关。不引起低血糖的剧烈游泳运动会减少与脑乳酸增加相关的脑糖原，这意味着即使没有低血糖，糖原在剧烈运动期间在脑能量学中的重要性。至少在海马和脑干中，激活的肾上腺素能调节是剧烈运动诱导的糖原分解的可能潜在机制。
Brain glycogen stored in astrocytes, a source of lactate as a neuronal energy source, decreases during prolonged exercise with hypoglycemia. However, brain glycogen dynamics during exercise without hypoglycemia remain unknown. Since intense exercise increases brain noradrenaline and serotonin as known inducers for brain glycogenolysis, we hypothesized that brain glycogen decreases with intense exercise not accompanied by hypoglycemia. To test this hypothesis, we employed a well-established acute intense exercise model of swimming in rats. Rats swam for fourteen 20 s bouts with a weight equal to 8 % of their body mass and were sacrificed using high-power (10 kW) microwave irradiation to inactivate brain enzymes for accurate detection of brain glycogen and monoamines. Intense exercise did not alter blood glucose, but did increase blood lactate levels. Immediately after exercise, brain glycogen decreased and brain lactate increased in the hippocampus, cerebellum, cortex, and brainstem. Simultaneously, serotonin turnover in the hippocampus and brainstem mutually increased and were associated with decreased brain glycogen. Intense swimming exercise that does not induce hypoglycemia decreases brain glycogen associated with increased brain lactate, implying an importance of glycogen in brain energetics during intense exercise even without hypoglycemia. Activated serotonergic regulation is a possible underlying mechanism for intense exercise-induced glycogenolysis at least in the hippocampus and brainstem.