Journal of the Korean Ophthalmological Society  2005;46(6):1060-1067

Characteristics of Nicotinic Receptor Expressed in Human Retinoblastoma.

Dae Ran KIM 1 ; Seung Kyu CHA ; In Deok KONG ; Se Hwan JUNG ; Sang Hoon RAH

Affiliations

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Keywords

Calcium; Nicotinic receptor; Retinoblastoma cell

Country

Republic of Korea

Language

Korean

Abstract

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 micro M). 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.