흰쥐 해마에서 Norepinephrine 유리에 미치는 N6-cyclopentyladenosine 및 Forskolin의 영향

• 영문명: Interaction of Forskolin with the Effect of N6-cyclopentyladenosine on Norepinephrine Release in Rat Hippocampus
• 발행기관: 대한생리학회-대한약리학회
• 저자명: 최봉규(Bong Kyu Choi) 김도경(Do Kyung Kim) 손용(Yong Son) 양의종(Ue Jong Yang)
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제1권 제3호, 225~231쪽, 전체 7쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1997.01.01

영문 초록

As it has been reported that the depolarization-induced norepinephrine (NE) release is modulated by activation of presynaptic A₁-adenosine heteroreceptor and various lines of evidence indicate the involvement of adenylate cyclase system in A₁-adenosine post-receptor mechanism in hippocampus, it was attempted to delineate the role of adenylate cyclase system in the A₁-receptor-mediated control of NE release in this study. Slices from rat hippocampus were equilibrated with [³H]-NE and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 Vcm^-1, 2 ms, rectangular pulses). The influence of various agents on the evoked tritium-outflow was investigated.

N⁶-Cyclopentyladenosine (CPA), a specific A₁-adenosine receptor agonist, in concentrations ranging from 0.1 to 10 ㄍM decreased the [³H]-NE release in a dose-dependent manner without any change of basal rate of release. 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 ㄍM), a selective A₁-receptor antagonist, inhibited the CPA effect. The responses to N-ethylmaleimide (3 & 10 ㄍM), a SH-alkylating agent of G-protein, were characterized by increments of the evoked NE-release and the CPA effects were completely abolished by NEM pretreatment. Forskolin, a specific adenylate cyclase activator, in concentrations ranging from 0.1 to 30 ㄍM increased the evoked and basal rate of NE release in a dose-dependent manner and the CPA effects were inhibited by forskolin pretreatment. Rolipram (1 & 10 ㄍM), a phosphodiesterase inhibitor, did not affect the evoked NE release, but reduced the CPA effect. And 8-bromo-cAMP (100 & 300 ㄍM), a membrane permeable cAMP analogue, inhibited the CPA effect significantly.

These results suggest that the A₁-adenosine heteroreceptor plays an important role in NE-release via nucleotide- binding protein G_i in the rat hippocampus and that the adenylate cyclase system might be participated in this process.

키워드

Forskolin N⁶-cyclopentyladenosine Norepinephrine Hippocampus