Loewi发现了从青蛙迷走神经释放的乙酰胆碱(ACh),以及Dale和Dudley在牛脾脏中发现了ACh,从而证明了神经冲动的化学传递。现在众所周知,ACh可以作为神经递质发挥作用。然而,ACh检测技术的进步导致了它在许多缺乏神经系统的生命形式中的发现,包括真细菌,古细菌,真菌,和植物。值得注意的是,已在无神经支配的哺乳动物细胞中发现了编码胆碱乙酰转移酶和毒蕈碱和烟碱ACh受体(nAChRs)的mRNA,包括免疫细胞,角质形成细胞,血管内皮细胞,心肌细胞,呼吸,和消化性上皮细胞。因此,非神经元胆碱能系统在多种哺乳动物细胞中表达,现在ACh不仅应该被认为是一种神经递质,但也作为非神经元胆碱能系统的局部调节剂。这里,我们讨论了非神经元胆碱能系统的作用,专注于免疫细胞。目前免疫细胞中非神经元胆碱能系统的研究热点是α7nAChRs,因为这些在巨噬细胞和T细胞上表达的受体参与调节炎症和免疫反应。这使得α7nAChRs成为有吸引力的潜在治疗靶标。
Loewi\'s discovery of acetylcholine (ACh) release from the frog vagus nerve and the discovery by Dale and Dudley of ACh in ox spleen led to the demonstration of chemical transmission of nerve impulses. ACh is now well-known to function as a neurotransmitter. However, advances in the techniques for ACh detection have led to its discovery in many lifeforms lacking a nervous system, including eubacteria, archaea, fungi, and plants. Notably, mRNAs encoding choline acetyltransferase and muscarinic and nicotinic ACh receptors (nAChRs) have been found in uninnervated mammalian cells, including immune cells, keratinocytes, vascular endothelial cells, cardiac myocytes, respiratory, and digestive epithelial cells. It thus appears that non-neuronal cholinergic systems are expressed in a variety of mammalian cells, and that ACh should now be recognized not only as a neurotransmitter, but also as a local regulator of non-neuronal cholinergic systems. Here, we discuss the role of non-neuronal cholinergic systems, with a focus on immune cells. A current focus of much research on non-neuronal cholinergic systems in immune cells is α7 nAChRs, as these receptors expressed on macrophages and T cells are involved in regulating inflammatory and immune responses. This makes α7 nAChRs an attractive potential therapeutic target.