Involvement of NMDA Receptor and L-type Calcium Channel in the Excitatory Action of Morphine

• 영문명: Involvement of NMDA Receptor and L-type Calcium Channel in the Excitatory Action of Morphine
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Bon Seop Koo Hong Kee Shin Suk Han Kang Jong Hun Jun
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제6권 제5호, 241~246쪽, 전체 6쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2002.01.01

영문 초록

We studied the excitatory action of morphine on the responses of dorsal horn neuron to iontophoretic application of excitatory amino acid and C-fiber stimulation by using the in vivo electrophysiological technique in the rat. In 137 of the 232 wide dynamic range (WDR) neurons tested, iontophoretic application of morphine enhanced the WDR neuron responses to N-methyl-D-aspartate (NMDA), kainate, and graded electrical stimulation of C-fibers. Morphine did not have any excitatory effects on the responses of low threshold cells. Morphine-induced excitatory effect at low ejection current was naloxone-reversible and reversed to an inhibitory action at high ejection current. NMDA receptor, calcium channel and intracellular Ca^2⁢ antagonists strongly antagonized the morphine-induced excitatory effect. These results suggest that changes in intracellular ionic concentration, especially Ca^2⁢, play an important role in the induction of excitatory effect of morphine in the rat dorsal horn neurons.

키워드

Dorsal horn neuron Morphine Excitatory action NMDA receptor Calcium channel