title: Toosendanin, a triterpenoid derivative, increases Ca2+ current in NG108-15 cells via L-type channels.
abstract: Toosendanin, a triterpenoid derivative extracted from Melia toosendan Sieb et Zucc, was demonstrated to be a selective presynaptic blocker and an effective antibotulismic agent in previous studies. Here, we observed its effects on Ca(2+) channels in NG108-15 cells by whole-cell patch-clamp recording. Obtained data showed that toosendanin concentration dependently increased the high-voltage-activated (HVA) Ca(2+) current with an EC(50) of 5.13 microM in differentiated NG108-15 cells. The enhancement effect was still observed when the cells were pretreated with 5 microM omega-conotoxin MVIIC. However, when the cells were preincubated with 5 microM nifedipine or 10 microM verapamil-containing solution, the effect was absent. In undifferentiated NG108-15 cells, which only express T-type Ca(2+) channels, toosendanin did not affect Ca(2+) currents. These results show that toosendanin increases Ca(2+) influx in NG108-15 cells via L-type Ca(2+) channels.
authors.affiliation: Key Laboratory of Neurobiology, Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, PR China.
authors.forename: Mu-Feng
authors.initials: MF
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Zhong-Feng
authors.initials: ZF
authors.lastname: Wang
authors.forename: Yu-Liang
authors.initials: YL
authors.lastname: Shi
mesh_terms: D000818:Animals; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009447:Neuroblastoma; D018408:Patch-Clamp Techniques / Q000379:methods; D014315:Triterpenes
chemical_list: D001464:Barium; D002118:Calcium; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D004365:Drugs, Chinese Herbal; C036454:toosendanin; D014315:Triterpenes