신생흰쥐 척수후근신경절 세포에서 전압의존성 K+ 전류의 동정

• 영문명: Characterization of Voltage-Gated Potassium Currents in Dorsal Root Ganglion Neurons of Neonatal Rats
• 발행기관: 대한생리학회-대한약리학회
• 저자명: 김지목(Ji mok Kim,) 정승준(Sung Jun Jung) 김상정(Sang Jeong Kim) 김전(Jun Kim)
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제1권 제6호, 613~624쪽, 전체 12쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1997.01.01

영문 초록

Dorsal root ganglion (DRG) is composed of neuronal cell bodies of primary afferents with diverse functions. Various types of ion channels present on DRG neurons may reflect those functions. In the present study, voltage-gated potassium currents in DRG neurons of neonatal rats were characterized by whole-cell voltage clamp method. Two types of delayed rectifier and three types of transient potassium currents were identified according to their electrophysiological properties. The delayed rectifier currents were named I_Ke (early inactivating) and I_Kl (late inactivating). Steady state inactivation of I_Ke began from -100 mV lasting until ⁣20 mV. I_Kl could be distinguished from I_Ke by its inactivation voltage range, from -70 mV to +10 mV. Three transient currents were named I_Af (fast inactivation), I_Ai (intermediate inactivation kinetics), and I_As (slow inactivation). I_Af showed fast inactivation with time constant of 10.6±2.0 msec, I_Ai of 36.9±13.9 msec, and I_As of 60.6±2.9 msec at ⁢30 mV, respectively. They also had distinct steady state inactivation range of each. Each cell expressed diverse combination of potassium currents. The cells most frequently observed were those which expressed both I_Kl and I_Af, and they had large diameters. The cells expressing I_Ke and expressing I_Ke, I_Ai, and I_As usually had small diameters. Judging from cell diameter, capsaicin sensitivity or action potential duration, candidates for nociceptor were the cells expressing I_Ke, expressing I_Ke and I_Ai, and expressing I_Ke and I_As. The types and distribution of potassium currents in neonatal rat DRG were similar to those of adult rat DRG (Gold et al, 1996b).

키워드

Dorsal root ganglion Potassium current Voltage clamp Characterization Neonatal rat