Characteristics of Nicotinic Receptor Expressed in Human Retinoblastoma.

Kim, Dae Ran; Cha, Seung Kyu; Kong, In Deok; Jung, Se Hwan; Rah, Sang Hoon

Original Article

Journal of the Korean Ophthalmological Society 2005;46(6):1060-1067.
Published online June 30, 2005.

Characteristics of Nicotinic Receptor Expressed in Human Retinoblastoma.

Dae Ran Kim, Seung Kyu Cha, In Deok Kong, Se Hwan Jung, Sang Hoon Rah

¹Department of Physiology, Yonsei University, Wonju College of Medicine, Wonju, Korea.
²Department of Ophthalmology, Yonsei University, Wonju College of Medicine, Wonju, Korea. shrah@wonju.yonsei.ac.kr

사람 망막아세포종 세포에 발현된 니코틴성 수용체의 특성

김대란¹,차승규¹,공인덕¹,정세환²,라상훈²

Department of Physiology, Yonsei University, Wonju College of Medicine,¹ Wonju, Korea Department of Ophthalmology, Yonsei University, Wonju College of Medicine,² Wonju, Korea

Correspondence: Dae-Ran Kim, Ph.D.¹

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.

Key Words: Calcium;Nicotinic receptor;Retinoblastoma cell