THE ADRENAL CHROMAFFIN CELL
THE ADRENAL CHROMAFFIN CELL
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DOI：
10.1038/scientificamerican0885-40
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发表时间：
1985-01-01
影响因子：
3
通讯作者：
WINKLER, H
中科院分区：
文献类型：
--
作者：
CARMICHAEL, SW;WINKLER, H
在恐惧或压力的情况下，肾上腺素的激增调动身体达到生理反应的高峰。肾上腺素以300倍于正常水平的浓度充斥血液，与不同器官细胞上的受体相互作用，增加心率和血压，促使肝脏释放额外的糖，为肌肉工作提供能量。这些反应合在一起构成了“战斗或逃跑”反应，使人准备好与敌人战斗或逃离危险。它们是肾上腺髓质分泌事件的最终结果：肾上腺髓质是位于肾脏上方的两个肾上腺的内部。在那里，被称为嗜铬细胞的特殊细胞制造、储存和分泌一种复杂的激素混合物，其中最重要的是肾上腺素。染色质细胞之所以引起人们的兴趣，不仅是因为它是“战或逃”反应的根源，还因为它们提供了观察其他分泌细胞，尤其是神经元或神经细胞的工作原理的途径。肾上腺髓质是一种内分泌腺：一种无管腺，通过向血液中释放激素来影响其他组织和器官。它也可以被认为是交感神经系统的一部分，帮助调节心率、肠道运动和瞳孔扩张等非自愿功能。与交感神经系统的神经元一样，肾上腺髓质受起源于脊髓的神经控制；它的主要激素肾上腺素与去甲肾上腺素密切相关，去甲肾上腺素是交感神经的特征性神经递质。（肾上腺素和去甲肾上腺素也分别被称为肾上腺素和去甲肾上腺素。）此外，肾上腺髓质本身也会产生一些去甲肾上腺素，它还会释放神经活性物质，即神经肽。
Under conditions of fear or stress a surge of the hormone adren aline mobilizes the body for peak physical response. Flooding the bloodstream at up to 300 times the normal concentration, the adrenaline interacts with receptors on cells in var ious organs, increasing the heart rate and blood pressure and prompting the release from the liver of extra sugar to fuel muscular work. Taken together these reactions constitute a" fight or flight" response that prepares one to combat an enemy or flee from danger. They are the end result of a secretory event in the adrenal medulla: the inner part of the two adrenal glands just above the kidneys. There specialized cells known as chromaffin cells manu facture, store and secrete a complex mixture of hormones, the most impor tant of which is adrenaline. Chromaffin cells are of interest not only as the root of the fight-or-flight reaction but also because they offer in sights into the workings of other secre tory cells, notably neurons, or nerve cells. The adrenal medulla is an en docrine gland: a ductless gland that affects other tissues and organs by discharging hormones into the blood stream. It can also be thought of, how ever, as part of the sympathetic ner vous system, which helps to regulate such involuntary functions as heart rate, intestinal movements and the di lation of the pupil. Like the neurons of the sympathetic system, the adrenal medulla is controlled by nerves origi nating in the spinal cord; its primary hormone, adrenaline, is closely relat ed to noradrenaline, the characteristic neurotransmitter of the sympathetic nerves.(Adrenaline and noradrenaline are also known respectively as epi nephrine and norepinephrine.) More over, the adrenal medulla itself se cretes some noradrenaline, and it also releases the neurologically active sub stances known as neuropeptides.