• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.61 no.11
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• pp.567-572
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• 2018

The sensory function of the trigeminal nerve is to provide tactile, proprioceptive, and nociceptive afference by chemical stimulation. Various physical responses of the trigeminal nerve to stimuli help to defend against harmful substances. Recently, many studies have been conducted on solitary chemoreceptor cells innervated by trigeminal nerve. Most volatile organic compounds stimulate both the olfactory and trigeminal nervous systems. In general, the trigeminal nervous system is less sensitive than the olfactory nervous system. Studies have shown that sensation of the trigeminal nerve by chemical stimulation results in inhibition of olfaction. This indicates that the olfactory and trigeminal nerves interact with each other in the central nervous system. It is important to study various noxious stimuli acting on the trigeminal nerve in modern society where environmental concerns are intensifying.

• Biomolecules & Therapeutics
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• v.20 no.6
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• pp.550-555
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• 2012

TRPA1 and TRPV1 are members of the TRP superfamily of structurally related, nonselective cation channels. TRPA1 and TRPV1 are often co-expressed in sensory neurons and play an important role in somatosense such as cold, pain, and irritants. The first leaves of Kalopanax pictus Nakai (Araliaceae) have long been used as a culinary ingredient in Korea because of their unique chemesthetic flavor. In this study, we observed the intracellular $Ca^{2+}$ response to cultured cells expressing human TRPA1 (hTRPA1) and human TRPV1 (hTRPV1) by $Ca^{2+}$ imaging analysis to investigate the ability of the first leaves of K. pictus to activate the hTRPA1 and hTRPV1. An 80% ethanol extract of K. pictus (KPEx) increased intracellular $Ca^{2+}$ influx in a response time- and concentration-dependent manner via either hTRPA1 or hTRPV1. KPEx-induced response to hTRPA1 was markedly attenuated by ruthenium red, a general blocker of TRP channels, and HC-030031, a specific antagonist of TRPA1. In addition, the intracellular $Ca^{2+}$ influx attained with KPEx to hTRPV1 was mostly blocked by ruthenium red, and capsazepine, a specific antagonist of TRPV1. These results indicate that KPEx selectively activates both hTRPA1 and hTRPV1, which may provide evidence that the first leaves of K. pictus primarily activate TRPA1 and TRPV1 to induce their unique chemesthetic sense.