Toosendanin, a triterpenoid derivative, acts as a novel agonist of L-type Ca2+channels in neonatal rat ventricular cells

  • Li M
  • Shi Y
  • 3

    Readers

    Mendeley users who have this article in their library.
  • 5

    Citations

    Citations of this article.

Abstract

Toosendanin, a triterpenoid derivative extracted from Melia toosendan Sieb et Zucc, was demonstrated to be potentially useful in medical and scientific researches. Here, we investigated the effects of toosendanin on L-type voltage-dependent Ca2+channels in cultured neonatal rat ventricular cells, using whole-cell patch-clamp method. Toosendanin irreversibly increased L-type Ca2+current (ICa(L)) in a concentration-dependent manner and shifted the maximum of the current/voltage relationship from 8.3±3.7 to 1.7±3.7 mV, without modifying the threshold potential of the current. Toosendanin shifted the steady-state activation and inactivation curves to the left. The deactivation kinetics of the ICa(L)was significantly slowed by toosendanin while the activation kinetics was not affected. The cells pretreated with 100 nM 1,4-dihydro-2,6-dimethyl-5-nitro-4- [2-(trifluoromethyl)phenyl]-3-pyridinecarboxylic acid methyl ester (S(-)-BayK8644) still respond to further addition of 87 μM toosendanin, and vice versa. These results prove toosendanin to be a novel L-type Ca2+channel agonist, which possesses a distinct binding site from BayK8644. © 2004 Elsevier B.V. All rights reserved.

Author-supplied keywords

  • Agonist
  • L-type Ca2+channel
  • Neonatal rat ventricular cell
  • Toosendanin
  • Whole-cell patch-clamp

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Mu Feng Li

  • Yu Liang Shi

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free