Aizawa H, Matsumoto K, Shigyo M, Inoue H, Koto H, Takata S, Hara N
Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Lung. 1994;172(4):241-9. doi: 10.1007/BF00164441.
We investigated the effects of epithelial cells on excitatory cholinergic neurotransmission in dog trachea, to shed more light on the role of airway epithelial cells in regulating airway responsiveness. Airway epithelial cells were prepared by an enzymatic dissociation of the tracheal mucosa using protease-free collagenase. Tracheal smooth muscle contractions evoked by electrical field stimulation (EFS) or acetylcholine (ACh) were measured before and after the application of epithelial cells. Isolated and dispersed epithelial cells (3 x 10(5) cells/ml) suppressed the amplitude of the twitch-like contractions evoked by EFS in the combined presence of guanethidine sulfate (10(-6) M) and indomethacin (10(-5) M). In contrast, epithelial cells did not affect the contraction evoked by exogenously applied ACh. Atropine (10(-6) M) or tetrodotoxin (10(-7) M) abolished the contraction evoked by electrical field stimulation. These findings indicate that airway epithelial cells inhibit the excitatory neurotransmission of the vagus nerve, presumably by suppressing the release of ACh. Airway epithelial cells may therefore play an important role in regulating the response of smooth muscle.
我们研究了上皮细胞对犬气管兴奋性胆碱能神经传递的影响，以更深入地了解气道上皮细胞在调节气道反应性中的作用。通过使用无蛋白酶胶原酶对气管黏膜进行酶解来制备气道上皮细胞。在施加上皮细胞之前和之后，测量电场刺激（EFS）或乙酰胆碱（ACh）引起的气管平滑肌收缩。在硫酸胍乙啶（10⁻⁶ M）和吲哚美辛（10⁻⁵ M）共同存在的情况下，分离和分散的上皮细胞（3×10⁵ 个细胞/ml）抑制了EFS引起的抽搐样收缩的幅度。相比之下，上皮细胞不影响外源性应用ACh引起的收缩。阿托品（10⁻⁶ M）或河豚毒素（10⁻⁷ M）消除了电场刺激引起的收缩。这些发现表明气道上皮细胞可能通过抑制ACh的释放来抑制迷走神经的兴奋性神经传递。因此，气道上皮细胞可能在调节平滑肌反应中起重要作用。
