Adrenergic responses of baroreceptive cells in the nucleus tractus solitarii of the rat: a microiontophoretic study.
Adrenergic responses of baroreceptive cells in the nucleus tractus solitarii of the rat: a microiontophoretic study.
复制标题
大鼠孤束核中压力感受细胞的肾上腺素反应：微离子电渗疗法研究。
DOI：
10.1016/0006-8993(87)91256-x
复制
发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Moises,HC
中科院分区：
文献类型：
--
作者：
Feldman,PD;Moises,HC
解剖学和药理学证据表明，在孤束核（NTS）内的压力感受器反射的调制中，儿茶酚胺（CA）的作用。本实验研究了大鼠孤束核（NTS）单个神经元对压力感受性反射激活和多巴胺、去甲肾上腺素（NE）、肾上腺素（EPI）离子导入的反应，以探讨压力感受性反射激活和CA应用对迷走神经感觉核压力感受性神经元的影响之间的关系。在研究的269个细胞中，104个（38.7%）表现出减少，41个（15.2%）表现出对压力反射激活的放电频率增加，而其余124个神经元显示无反应。所有3种CA均抑制大多数（68.5%）NTS细胞的峰电位活性。观察到这些对自发放电的抑制作用，而不管特定神经元对压力反射激活的反应曲线如何。NE和EPI对NTS神经元活动的抑制作用可被α-肾上腺素能受体拮抗剂妥拉苏林特异性阻断，而不被β-肾上腺素能受体拮抗剂索他洛尔阻断。这些结果表明CA可能在NTS内的几个位点相互作用以影响压力感受性反射整合，NE和EPI对神经元活动的影响是由α-肾上腺素能受体介导的。
Anatomical and pharmacological evidence suggests a role for catecholamines (CAs) in the modulation of the baroreceptor reflex within the nucleus tractus solitarii (NTS). Single neurons in the NTS of the rat were studied for their responses to activation of the baroreceptor reflex and to iontophoretic administration of dopamine, norepinephrine (NE), and epinerphrine (EPI) to determine the relationship between the effects of baroreflex activation and CA application on baroreceptive neurons in the vagal sensory nucleus. Of 269 cells studied, 104 (38.7%) exhibited decreases and 41 cells (15.2%) showed increases in firing rate in response to baroreflex activation, while the remaining 124 neurons showed no response. All 3 CAs inhibited spike activity in the majority (68.5%) of NTS cells. These inhibitory effects on spontaneous firing were observed regardless of the response profile of a particular neuron to baroreflex activation. The inhibitory effects of NE and EPI on NTS neuronal activity were specifically blocked by the α-adrenergic receptor antagonist tolazoline, but not by the β-adrenergic antagonist sotalol. These results indicate that CAs may interact at several sites within the NTS to influence baroreflex integration, and that the effects of NE and EPI on neuronal activity are mediated by an α-adrenergic receptor.