Mravec Boris, Ondicova Katarina, Tillinger Andrej, Pecenak Jan
Institute of Physiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia; Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia.
Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia; Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
Auton Neurosci. 2015 Jul;190:20-5. doi: 10.1016/j.autneu.2015.04.003. Epub 2015 Apr 25.
Neuroendocrine stress response is regulated by several feedback loops. Since it has been suggested that afferent vagal pathways contribute to these feedback loops, we examined the effect of surgical subdiaphragmatic vagotomy on both baseline and stress-induced increases in plasma epinephrine, norepinephrine, and corticosterone levels in vagotomized and sham-operated Sprague Dawley rats. On either the 3rd or 14th day following vagotomy, the animals were exposed to acute immobilization stress and blood from the jugular vein was collected both before and during stress exposure. We found that vagotomy significantly enhanced immobilization-induced increases of plasma epinephrine, norepinephrine, and corticosterone levels on the 3rd day following surgery. However, on the 14th day following surgery, vagotomy enhanced only increase of plasma epinephrine levels in stressed rats. Our data indicate that afferent pathways of the vagus nerve are involved in negative feedback regulation of epinephrine secretion from the adrenal medulla during stressful conditions. We hypothesize that this feedback mechanism might be mediated by the binding of circulating epinephrine on β2-adrenergic receptors localized on sensory endings of the vagus nerve.
神经内分泌应激反应受多个反馈回路调节。鉴于有研究表明传入迷走神经通路参与这些反馈回路，我们研究了手术切断膈下迷走神经对迷走神经切断术大鼠和假手术的斯普拉格-道利大鼠血浆肾上腺素、去甲肾上腺素和皮质酮水平的基线及应激诱导升高的影响。在迷走神经切断术后第3天或第14天，将动物暴露于急性制动应激，并在应激暴露前和暴露期间从颈静脉采集血液。我们发现，迷走神经切断术在术后第3天显著增强了制动诱导的血浆肾上腺素、去甲肾上腺素和皮质酮水平的升高。然而，在术后第14天，迷走神经切断术仅增强了应激大鼠血浆肾上腺素水平的升高。我们的数据表明，迷走神经的传入通路参与应激状态下肾上腺髓质肾上腺素分泌的负反馈调节。我们推测，这种反馈机制可能是由循环肾上腺素与位于迷走神经感觉末梢的β2-肾上腺素能受体结合介导的。
