The long-term effect of toosendanin on current through nifedipine-sensitive Ca2+ channels in NG108-15 cells.
Toosendanin is a triterpenoid derivative extracted from Melia toosendan Sieb et Zucc. Previous studies demonstrated that toosendanin could block neurotransmission and stimulate PC12 cell into differentiation and apoptosis. These actions of toosendanin were suggested to result from a continuous increase in Ca2+ influx, which led to intracellular Ca2+ overload. Here, we observed the long-term effect of toosendanin on Ca2+ channels in NG108-15 cells by whole-cell patch-clamp recording. Obtained data showed that a prolonged exposure to toosendanin induced a continuous increase in the Ca2+ influx in a concentration and time-dependent manner while a brief treatment induced an irreversible increase in Ca2+ influx in differentiated NG108-15 cells. The nifedipine-sensitive L-type currents were significantly increased after exposure to TSN while the nifedipine-resistant or omega-conotoxin MVIIC-sensitive currents were not affected.
Li
Mu-Feng
MF
Key Laboratory of Neurobiology, Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, People's Republic of China.
Shi
Yu-Liang
YL
D000818:Animals; D001464:Barium / Q000502:physiology; D002118:Calcium / Q000502:physiology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects* / Q000378:metabolism; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009543:Nifedipine / Q000494:pharmacology; D013997:Time Factors; D020960:omega-Conotoxins; D014315:Triterpenes
D001464:Barium; D002118:Calcium; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004365:Drugs, Chinese Herbal; D009543:Nifedipine; D020960:omega-Conotoxins; C075851:omega-conotoxin-MVIIC; C036454:toosendanin; D014315:Triterpenes