Li D, Shirakami G, Zhan X, Johns R A
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
Am J Respir Cell Mol Biol. 2000 Aug;23(2):175-81. doi: 10.1165/ajrcmb.23.2.4022.
Nitric oxide (NO) upregulates ciliary beat frequency (CBF). The present study evaluates mechanisms of the NO-cyclic guanosine monophosphate (cGMP) pathway regulation of CBF. Rat tracheal explants were loaded with 4,5-diaminofluorescein diacetate for the demonstration of NO production by ciliated epithelial cells after L-arginine (L-Arg) stimulation. CBF was measured using phase contrast microscopy and videotape analysis. The roles of NO, soluble guanylate cyclase (sGC), cGMP-dependent protein kinase (PK) G, and phosphodiesterase (PDE) V in regulation of CBF were evaluated. NO synthase (NOS) was activated with L-Arg or inhibited with N(G)-monomethyl-L-Arg. sGC was stimulated with NO donors 1-hydroxy-2-oxo-3- (N-ethyl-2-aminoethyl)-3-ethyl-1-triazene and S-nitroso-L-glutathione or mimicked by 8-bromo-guanosine 3', 5'-cyclic monophosphate (8-Br-cGMP) and inhibited with 1H-[1,2, 4]oxadiazole[4,3-a]quinoxalin-1-one. The effects of the PKG inhibition with KT5823 and PDE V inhibition with Zaprinast were also examined. The studies demonstrate that ciliated epithelial cells produce NO, which is correlated with CBF stimulation. L-Arg dose- and time-dependently increases CBF, and NO donors, 8-Br-cGMP, and Zaprinast also enhance CBF. Inhibitors of NOS, sGC, and PKG can block the stimulant effect of L-Arg on CBF. Thus, NO is a regulator of CBF acting via sGC and PKG. The NO-cGMP signaling pathway regulates CBF in an autocrine manner in cultured rat ciliated airway epithelium.
一氧化氮（NO）可上调纤毛摆动频率（CBF）。本研究评估了NO-环磷酸鸟苷（cGMP）途径对CBF的调节机制。用4,5-二氨基荧光素二乙酸酯加载大鼠气管外植体，以证明L-精氨酸（L-Arg）刺激后纤毛上皮细胞产生NO。使用相差显微镜和录像分析测量CBF。评估了NO、可溶性鸟苷酸环化酶（sGC）、cGMP依赖性蛋白激酶（PK）G和磷酸二酯酶（PDE）V在CBF调节中的作用。用L-Arg激活一氧化氮合酶（NOS）或用N（G）-单甲基-L-精氨酸抑制。用NO供体1-羟基-2-氧代-3-（N-乙基-2-氨基乙基）-3-乙基-1-三氮烯和S-亚硝基-L-谷胱甘肽刺激sGC，或用8-溴鸟苷3'，5'-环一磷酸（8-Br-cGMP）模拟，并用1H-[1,2,4]恶二唑[4,3-a]喹喔啉-1-酮抑制。还研究了用KT5823抑制PKG和用扎普司特抑制PDE V的效果。研究表明，纤毛上皮细胞产生NO，这与CBF刺激相关。L-Arg剂量和时间依赖性地增加CBF，NO供体、8-Br-cGMP和扎普司特也增强CBF。NOS、sGC和PKG的抑制剂可阻断L-Arg对CBF的刺激作用。因此，NO是通过sGC和PKG起作用的CBF调节剂。在培养的大鼠纤毛气道上皮中，NO-cGMP信号通路以自分泌方式调节CBF。
