Facilitation of cholinergic transmission by huperzine A in toad paravertebral ganglia in vitro
Zhang, G.B.; Wang, M.Y.; Zheng, J.Q.; Tang, X.C.
Zhongguo Yao Li Xue Bao 15(2): 158-161
1994
ISSN/ISBN: 0253-9756 PMID: 8010112 Document Number: 434871
Using the intracellular recording techniques of toad paravertebral ganglia (PVG), the effects of cholinesterase inhibitor huperzine A (Hup-A), an alkaloid first isolated from Huperzia serrata (Thunb) Trev in China, on the synaptic transmission were studied. In 30 PVG cells tested, no remarkable changes in membrane potential and input resistance were observed during superfusion of Hup-A 0.3 or 1 mu-mol cntdot L-1 for 15 min. The rate of orthodromic action potential evoked by preganglionic stimulation was increased by Hup-A 0.3 or 1 mu-mol cntdot L-1 (n = 12, P lt 0.05), and much faster, stronger, and longer in action at 50 or 100 mu-mol cntdot L-1 (n = 11). The amplitude and duration of exogenous acetylcholine-, but not carbachol-, induced depolarization were increased (P lt 0.05). It is concluded that Hup-A is a selective and potent cholinesterase inhibitor, by which action it facilitates the cholinergic transmission of PVG neurons.