Fischer A, Mundel P, Mayer B, Preissler U, Philippin B, Kummer W
Institute for Anatomy and Cell Biology I, University of Heidelberg, FRG.
Neurosci Lett. 1993 Jan 12;149(2):157-60. doi: 10.1016/0304-3940(93)90760-i.
The inhibitory non-adrenergic non-cholinergic (i-NANC) innervation of the guinea pig airways was suggested to be mediated, at least partially, by nitric oxide (NO). The enzyme catalyzing the generation of NO and citrulline from L-arginine, nitric oxide synthase (NOS), was found to be identical with neuronal nicotinamide-adenine dinucleotide hydrogen phosphate (NADPH)-diaphorase. In the present study, we report the distribution of NOS in guinea pig lower airways and in vagal sensory and sympathetic ganglia as revealed by NOS immunohistochemistry and NADPH-diaphorase histochemistry. The distribution of NOS was identical using either technique and displayed a similar distribution pattern in all parts of the lower airways. Yet, the number of NOS-containing fibres was increasing from cervical trachea towards principal bronchi and decreasing to complete absence in bronchioli. Innervation with NOS-containing nerve fibres was densest in the smooth muscle layer and in the lamina propria of the mucosa. Single fibres were found in the respiratory epithelium. Labelling was absent from nerve fibres innervating the submucosal glands. Perivascular fibre networks enmeshed tracheal arteries, pulmonary arteries and veins. A substantial number of NOS-immunoreactive and NADPH-diaphorase-positive neurons was observed in vagal sensory ganglia, whereas such neurons were rather sparse in sympathetic ganglia. Tracheal and peribronchial ganglia of the airways were devoid of labelling. These findings suggest that extrinsic rather than intrinsic (tracheal and peribronchial) neurons are the source of NO release from guinea pig airway nerve fibres after electrical field stimulation. These extrinsic nerve fibres may originate from both sympathetic and vagal sensory ganglia.
豚鼠气道的抑制性非肾上腺素能非胆碱能（i-NANC）神经支配被认为至少部分是由一氧化氮（NO）介导的。催化从L-精氨酸生成NO和瓜氨酸的酶，一氧化氮合酶（NOS），被发现与神经元烟酰胺腺嘌呤二核苷酸磷酸（NADPH）黄递酶相同。在本研究中，我们报告了通过NOS免疫组织化学和NADPH黄递酶组织化学揭示的NOS在豚鼠下气道以及迷走神经感觉和交感神经节中的分布。使用这两种技术时，NOS的分布是相同的，并且在下气道的所有部位都显示出相似的分布模式。然而，含NOS的纤维数量从颈段气管向主支气管逐渐增加，在细支气管中减少至完全不存在。含NOS神经纤维的神经支配在平滑肌层和粘膜固有层中最密集。在呼吸上皮中发现了单根纤维。支配粘膜下腺的神经纤维没有标记。血管周围纤维网络围绕着气管动脉、肺动脉和静脉。在迷走神经感觉节中观察到大量NOS免疫反应性和NADPH黄递酶阳性神经元，而在交感神经节中这类神经元相当稀少。气道的气管和支气管周围神经节没有标记。这些发现表明，在电场刺激后，豚鼠气道神经纤维释放NO的来源是外在神经元而非内在（气管和支气管周围）神经元。这些外在神经纤维可能起源于交感神经节和迷走神经感觉节。
