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 + imaging technique and the patch clamp method. Results: 1) Nicotine-induced [+]i rise arose entirely through + influx, which was completely abolished by hexamethonium (100 ). 2) Nicotine also induced remarkable depolarization from -56.63.7 mV to -29.63.6 mV (n=4) under current clamp mode, but it failed to directly activate the T-type + 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.