The Inhibitory Effect of Opioid on the Hyperpolarization-Activated Cation Currents in Rat Substantia Gelatinosa Neurons

• 영문명: The Inhibitory Effect of Opioid on the Hyperpolarization-Activated Cation Currents in Rat Substantia Gelatinosa Neurons
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Geun Hee Seol,Jun Kim Sun Hee Cho Won Ki Kim Jong Whan Kim Sang Jeong Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제5권 제5호, 373~380쪽, 전체 8쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2001.01.01

영문 초록

The action of opioid on the hyperpolarization-activated cation current (I_h) in substantia gelatinosa neurons were investigated by using whole-cell voltage-clamp recording in rat spinal brain slices. Hyperpolarizing voltage steps revealed slowly activating currents in a subgroup of neurons. The half-maximal activation and the reversal potential of the current were compatible to neuronal I_h. DAMGO (1μM), a selective- opioid agonist, reduced the amplitude of I_h reversibly. This reduction was dose-dependent and was blocked by CTOP (2μM), a selective μ-opioid antagonist. DAMGO shifted the voltage dependence of activation to more hyperpolarized potential. Cesium (1 mM) or ZD 7288 (100μM) blocked I_h and the currents inhibited by cesium, ZD 7288 and DAMGO shared a similar time and voltage dependence. These results suggest that activation of μ-opioid receptor by DAMGO can inhibit I_h in a subgroup of rat substantia gelatinosa neurons.

키워드

Substantia gelatinosa Spinal cord Hyperpolarization-activated cation current (I_h) Opioid DAMGO Pain