Antagonism of 5-HT3 receptor mediated currents in murine N1E-115 neuroblastoma cells by (+)-tubocurarine.
5-HT3 receptor-mediated membrane currents were recorded from voltage-clamped clonal N1E-115 neuroblastoma cells. The inward current response to ionophoretically applied serotonin (5-HT) was reversibly antagonised by the 5-HT3 receptor antagonists GR 38032F and metoclopramide with IC50 values of 0.2 nM and 14 nM, respectively. Low concentrations of (+)-tubocurarine [+)-Tc) also blocked the response to 5-HT (IC50 = 0.8 nM), but other nicotinic cholinoceptor antagonists (gallamine, vecuronium and trimetaphan) were ineffective when applied at a relatively high concentration (1 microM). Blockade by (+)-Tc was neither voltage- nor use-dependent, suggesting that (+)-Tc does not block 5-HT-activated ion channels in N1E-115 cells.
Department of Pharmacology and Clinical Pharmacology, Ninewells Hospital, Dundee, U.K.
J A
JA
Peters
H M
HM
Malone
J J
JJ
Lambert
D000818:Animals; D002460:Cell Line; D007093:Imidazoles / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D017294:Ondansetron; D011978:Receptors, Nicotinic / Q000187:drug effects; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012702:Serotonin Antagonists; D014403:Tubocurarine / Q000494:pharmacology*
D007093:Imidazoles; D007473:Ion Channels; D011978:Receptors, Nicotinic; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017294:Ondansetron; D014403:Tubocurarine