목적: Nasal cavity encounters various irritants during inhalation. To detect and remove these irritants, nasal mucosa epithelium may have a specialized sensing system. Oral cavity, on the other hand, is known to have bitter taste receptors (T2Rs) to detect harmful substances not to ingest them. Recently, T2Rs have been identified in human airway epithelium. Here we show that human T2R receptors function also in nasal mucosa epithelium. 방법: Human nasal epithelium were harvested from 13 patients. Harvested epitheliums were incubated for 12 hours and total RNA were extracted. The total RNA were reverse-transcripted to cDNA and polymerase chain reaction (PCR) was conducted. Ciliary bear frequency (CBF) was measured using optical flow technique with a peak detection method for CBF measurement program. The most actively moving phases were recorded by 50~100 frames/second, and the CBF was automatically calculated by the self- developed program. We treated the bitter molecules to the stabilized cells, and the CBF was measured after 5, 10, 20 minutes. Each experiment was repeated 3 times. 결과: We identified the expression of T2R family in human nasal epithelium with RT-PCR using 25 primers specific to human T2Rs. Among them, 15 mRNAs were expressed. However, the expression frequency was different by the types of T2Rs. T2R13 and T2R39 were found in only 4 patients, on the other hand, T2R14 and T2R47 were found in 12 patients. We measured the CBF to know if the T2Rs in human nasal epithelium had functions. The agonists for specific T2R was applied, and the CBF was measured for 20 minutes. Each agonist-treated cells showed increased CBF dose-dependently, with the peak at 10 minutes. 결론: T2Rs of human nasal epithelium have physiologic function in sensation of the toxic substances and increase in ciliary movement as a primary defense mechanism.