사람 망막아세포종 세포에 발현된 니코틴성 수용체의 특성

Characteristics of Nicotinic Receptor Expressed in Human Retinoblastoma

Purpose: To identify the characteristics and physiological function of the nicotinic receptor expressed in human retinoblastoma cells. Methods: We measured possible nicotinic signaling in WERI-Rb-1 cells using the Ca2+ imaging technique and the patch clamp method. Results: 1) Nicotine-induced [Ca2+]i rise arose entirely through Ca2+ influx, which was completely abolished by hexamethonium (100 μM). 2) Nicotine also induced remarkable depolarization from -56.6±3.7 mV to -29.6±3.6 mV (n=4) under current clamp mode, but it failed to directly activate the T-type Ca2+ channel expressed in retinoblastoma cells. Conclusions: Nicotinic activation can increase the intracellular calcium level through calcium influx in the undifferentiated retinoblastoma cells, which may play important roles in cell proliferation, differentiation, and cell death.