Anteroventral third ventricle lesions abolish lumbar sympathetic responses to insulin.
Anteroventral third ventricle lesions abolish lumbar sympathetic responses to insulin.
复制标题
前腹侧第三脑室病变消除了腰部交感神经对胰岛素的反应。
DOI：
10.1161/01.hyp.23.6.1059
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Johnson,AK
中科院分区：
文献类型：
--
作者：
Muntzel,M;Beltz,T;Mark,AL;Johnson,AK
胰岛素已被证明可以增加交感神经活动。因为有证据表明胰岛素在中枢神经系统内起作用，所以我们假设前腹侧第三脑室区域（富含胰岛素受体的区域）的病变将消除对高胰岛素血症的交感神经反应。我们在正常血糖钳夹期间以 0.13 U/h 静脉注射胰岛素之前和之后，测量了禁食、麻醉的假损伤组 (n = 8) 和损伤组 (n = 8) 大鼠的平均动脉压和腰交感神经活动。另外的假损伤（n = 10）和损伤（n = 5）大鼠接受载体输注。注射胰岛素的假损伤大鼠的腰交感神经活动（+83 +/- 18%）比注射媒介物的假损伤大鼠（+27 +/- 4%）显着增加。最重要的是，注射胰岛素的病变大鼠的交感神经活动增加（+32 +/- 11%），但不高于接受媒介物的病变大鼠（+23 +/- 16%）。胰岛素或媒介物不会改变血压。为了测试第三脑室前腹区损伤非特异性抑制交感神经兴奋反应的可能性，我们评估了假损伤（n = 5）和损伤（n = 8）大鼠腰交感神经活动对硝酸甘油的反射增加。在硝酸甘油引起的低血压期间，有病变和假病变的大鼠表现出腰神经活动的类似增加。总之，静脉注射胰岛素引起的交感神经活动的增加被前腹侧第三脑室病变所消除。这些数据表明，该大脑区域的完整性对于通过全身施用胰岛素激活腰交感神经活动是必要的。
Insulin has been shown to increase sympathetic nerve activity. Because evidence shows that insulin acts within the central nervous system, we hypothesized that lesions of the anteroventral third ventricle region, an area rich in insulin receptors, would abolish sympathetic responses to hyperinsulinemia. We measured mean arterial pressure and lumbar sympathetic nerve activity in fasted, anesthetized sham-lesioned (n = 8) and lesioned (n = 8) rats before and after intravenous insulin infusion at 0.13 U/h during euglycemic clamp. Additional sham-lesioned (n = 10) and lesioned (n = 5) rats received vehicle infusion. Insulin-infused sham-lesioned rats had substantially greater increases in lumbar sympathetic nerve activity (+83 +/- 18%) than vehicle-infused sham-lesioned rats (+27 +/- 4%). Most importantly, insulin-infused lesioned rats had increases in sympathetic activity (+32 +/- 11%) that were no greater than lesioned rats receiving vehicle (+23 +/- 16%). Blood pressure was not altered by insulin or vehicle. To test the possibility that lesions of the anteroventral third ventricle region nonspecifically suppress sympathetic excitatory responses, we evaluated reflex increases in lumbar sympathetic activity to nitroglycerin in sham-lesioned (n = 5) and lesioned (n = 8) rats. Rats with lesions and sham lesions showed comparable increases in lumbar nerve activity during nitroglycerin-induced hypotension. In summary, increases in sympathetic nerve activity to intravenous insulin infusion are abolished by anteroventral third ventricle lesions. These data indicate that the integrity of this brain region is necessary for activation of lumbar sympathetic nerve activity by systemic administration of insulin.