Noradrenergic and GABAergic systems in the medial hypothalamus are activated during hypoglycemia
Noradrenergic and GABAergic systems in the medial hypothalamus are activated during hypoglycemia
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DOI：
10.1152/ajpregu.2001.280.2.r563
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发表时间：
2001-02-01
影响因子：
2.8
通讯作者：
Arseneau, LM
中科院分区：
文献类型：
--
作者：
Beverly, JL;De Vries, MG;Arseneau, LM
内侧下丘脑中的去甲肾上腺素能和 GABA 能系统影响血浆葡萄糖，并可能在糖缺乏期间被激活。将微透析探针置于雄性 Sprague-Dawley 大鼠的腹内侧核 (VMH)、下丘脑外侧核 (LHA) 和室旁核 (PVH) 中，以监测去甲肾上腺素 (NE) 和 GABA 的细胞外浓度。在胰岛素（1.0 U/kg）引起的全身低血糖期间，在胰岛素给药后的前10分钟和20-30分钟内，VMH（P < 0.05）和PVH（P = 0.06）中的NE浓度以双峰方式增加。在VMH中，GABA浓度以与NE类似的方式增加(P,0.05)。 LHA 中的细胞外 NE 浓度略低 (P = 0.13)，GABA 水平保持在基线水平。在正常血糖钳夹期间，VMH 中的 NE 和 GABA 没有增加；然而，PVH 中的 NE 仍然增加，反映了对高胰岛素血症的直接反应。基于这些数据，我们提出，低血糖期间，内侧下丘脑去甲肾上腺素能传入神经的活性增加，并影响局部 GABA 能系统的活性，以激活适当的生理代偿机制。
Noradrenergic and GABAergic systems in the medial hypothalamus influence plasma glucose and may be activated during glucoprivation. Microdialysis probes were placed into the ventromedial nucleus (VMH), lateral hypothalamus (LHA), and paraventricular nucleus (PVH) of male Sprague-Dawley rats to monitor extracellular concentrations of norepinephrine (NE) and GABA. During systemic hypoglycemia, induced by insulin (1.0 U/kg), NE concentrations increased in the VMH (P < 0.05) and PVH (P = 0.06) in a bimodal fashion during the first 10 min and 20-30 min after insulin administration. In the VMH, GABA concentrations increased (P,0.05) in a similar manner as NE. Extracellular NE concentrations in the LHA were slightly lower (P = 0.13), and GABA levels remained at baseline. The increases in NE and GABA in the VMH were absent during euglycemic clamp; however, NE in the PVH still increased, reflecting a direct response to hyperinsulinemia. On the basis of these data, we propose that the activity of noradrenergic afferents to the medial hypothalamus is increased during hypoglycemia and influences the activity of local GABAergic systems to activate appropriate physiological compensatory mechanisms.