Native serotonin 5-HT3 receptors expressed in Xenopus oocytes differ from homopentameric 5-HT3 receptors.
Efficacies of the 5-hydroxytryptamine (serotonin) 5-HT3 receptor (5-HT3R) agonists 2-methyl-5-HT, dopamine, and m-chlorophenylbiguanide on 5-HT3R native to N1E-115 cells and on homopentameric 5-HT3R expressed in Xenopus oocytes were determined relative to that of 5-HT. Efficacies of 2-methyl-5-HT and dopamine on 5-HT3R native to differentiated N1E-115 cells are high (54 and 36%) as compared with their efficacies on homopentameric 5-HT3R-A(L) and 5-HT3R-A(S) receptors expressed in oocytes (4-8%). m-Chlorophenylbiguanide does not distinguish between 5-HT3R in N1E-115 cells and in oocytes. The distinct pharmacological profile of 5-HT3R native to differentiated N1E-115 cells is conserved when poly(A)+ mRNA from these cells is expressed in oocytes. The results indicate that, apart from the known 5-HT3R subunits, N1E-115 cells express additional proteins involved in 5-HT3R function.
van Hooft
J A
JA
Research Institute of Toxicology, Utrecht University, The Netherlands.
Kreikamp
A P
AP
Vijverberg
H P
HP
D000818:Animals; D001645:Biguanides / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology; D005260:Female; D007700:Kinetics; D046911:Macromolecular Substances; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D009447:Neuroblastoma; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010957:Plasmids; D012333:RNA, Messenger / Q000378:metabolism; D011985:Receptors, Serotonin / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology*; D044406:Receptors, Serotonin, 5-HT3; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014981:Xenopus
D001645:Biguanides; D046911:Macromolecular Substances; D012333:RNA, Messenger; D011985:Receptors, Serotonin; D044406:Receptors, Serotonin, 5-HT3; D017366:Serotonin Receptor Agonists; D012701:Serotonin; C045918:2-methyl-5-HT; C065734:1-(3-chlorophenyl)biguanide; D004298:Dopamine