Sensory receptor activation by mediators of defense reflexes in guinea-pig lungs
Sensory receptor activation by mediators of defense reflexes in guinea-pig lungs
复制标题
DOI：
10.1016/s0034-5687(97)00030-3
复制
发表时间：
1997-06-01
期刊：
影响因子：
--
通讯作者：
Bergren, DR
中科院分区：
文献类型：
--
作者：
Bergren, DR
组胺和缓激肽是肺防御期间肺内释放的介质。肺部快速适应受体 (RAR) 和传入 C 纤维都被认为可以启动这些介质引起的防御反射。然而，尚不清楚感觉末梢是否是由这些介质直接刺激，而不是由机械变化间接刺激。因此，在麻醉豚鼠中，肺部 RAR 和 C 纤维受到组胺、缓激肽和辣椒素气溶胶的攻击。在组胺激发期间，气管压力 (P-Tr) 和 RAR 神经活动 (NA) 同时增加。在施用异丙肾上腺素以减弱 P-Tr 的增加后，组胺诱导的 RAR NA 的增加也同样减弱。缓激肽或辣椒素激发的结果相似。因此，组胺、辣椒素和缓激肽对 RAR 的激活取决于肺力学的变化。在 P-Tr 发生任何变化之前，C 纤维被辣椒素或缓激肽激活。然而，尽管 P-Tr 大幅增加，但 C 纤维并未受到组胺挑战的影响。 C 纤维直接被辣椒素或缓激肽激活，但不能被组胺激活。 (C) 1997 Elsevier Science B.V.
Histamine and bradykinin are mediators released within the lungs during lung defense. Both pulmonary rapidly-adapting receptors (RARs) and afferent C-fibers have been suggested to initiate defense reflexes evoked by these mediators. However, it is not known whether the sensory endings are directly stimulated by these mediators rather than indirectly by mechanical changes. Therefore, pulmonary RARs and C-fibers were challenged with aerosols of histamine, bradykinin and capsaicin in anesthetized guinea pigs. During histamine challenge tracheal pressure (P-Tr) and RAR nerve activity (NA) increased concurrently. After isoproterenol administration to attenuate increases in P-Tr, histamine-induced increases in RAR NA were similarly attenuated. Results with bradykinin or capsaicin challenge were similar. Therefore activation of RARs by histamine, capsaicin and bradykinin was dependent upon changes in lung mechanics. C-fibers were activated by capsaicin or bradykinin prior to any changes in P-Tr. However, C-fibers were not affected by histamine challenge despite substantial increases in P-Tr. C-fibers are activated directly by either capsaicin or bradykinin but not by histamine. (C) 1997 Elsevier Science B.V.