EFFECTS OF PLASMA ANGIOTENSIN-II AND HYPERNATREMIA ON SUBFORNICAL ORGAN NEURONS
EFFECTS OF PLASMA ANGIOTENSIN-II AND HYPERNATREMIA ON SUBFORNICAL ORGAN NEURONS
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DOI：
10.1152/ajpregu.1988.254.5.r746
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发表时间：
1988-05-01
影响因子：
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通讯作者：
MOGENSON, GJ
中科院分区：
文献类型：
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作者：
GUTMAN, MB;CIRIELLO, J;MOGENSON, GJ
采用尿素麻醉大鼠，观察血浆血管紧张素II （ANG II）和高钠血症对直接投射到下丘脑室旁核（PVH）、视上核（SON）和中隔核（NM）的皮质下器官（SFO）神经元兴奋性的影响。对SFO中106个反方向识别的神经元进行细胞外记录。颈动脉内灌注angii和/或0.5 M高渗NaCl可增加53（50%）的放电频率。颈动脉内注射等渗盐水或静脉注射苯肾上腺素均未改变SFO神经元的放电率。在38个PVH突出的神经元中，21个（55%）对ANG II和/或高渗NaCl有反应：9个只对ANG II有反应，8个只对高渗NaCl有反应，4个对两者都有反应。同样，在42个SON投射神经元中，30个（71%）对ANG II和/或高渗NaCl有反应：10个只对ANG II有反应，15个只对高渗NaCl有反应，5个对两者都有反应。最后，在26个NM突起神经元中，1个神经元的放电频率增加到ANG II， 1个神经元的放电频率增加到0.5 N NaCl。另外8个SFO神经元倾向于向PVH和SON （n = 6）以及PVH和NM （n = 2）发送侧支轴突，其中4个神经元以不同的组合对颈动脉内注入ANG II和0.5 M NaCl有反应。这些数据表明，血源性ANG II和血浆高钠血症可以通过改变SFO神经元投射到含有大细胞神经分泌加压素神经元和交感神经兴奋通路组成神经元的前脑结构的放电率，影响动脉压和垂体后叶加压素的释放。
Experiments were done in urethan-anesthetized rats to investigate the effect of plasma angiotensin II (ANG II) and hypernatremia on the excitability of subfornical organ (SFO) neurons projecting directly to paraventricular nucleus of the hypothalamus (PVH), supraoptic nucleus (SON), and nucleus medianus (NM). Extracellular recordings were made from 106 antidromically identified neurons in the SFO. The firing frequency of 53 (50%) was increased by the intracarotid infusion of ANG II and/or 0.5 M hypertonic NaCl. The intracarotid infusion of isotonic saline or the intravenous infusion of phenylephrine did not alter the discharge rate of these SFO neurons. Of 38 PVH projecting neurons, 21 (55%) responded to ANG II and/or hypertonic NaCl: 9 to ANG II only, 8 to hypertonic NaCl only, and 4 to both. Similarly, of 42 SON projecting neurons, 30 (71%) responded to ANG II and/or hypertonic NaCl: 10 to ANG II only, 15 to hypertonic NaCl only, and 5 to both. Finally, of 26 NM projecting neurons, one increased its firing frequency to ANG II and one to 0.5 N NaCl. An additional eight SFO neurons were fond to send collateral axons to both the PVH and SON (n = 6) and PVH and NM (n = 2): four responded in various combinations to intracarotid infusion of ANG II and 0.5 M NaCl. These data suggest that blood-borne ANG II and plasma hypernatremia can influence arterial pressure and the release of vasopressin from the neurophypophysis by altering the discharge rate of SFO neurons projecting to forebrain structures that contain magnocellular neurosecretory vasopressin neurons and neurons that are components of sympathoexcitatory pathways.