Characterization of 5-HT transporter and receptor system in HeLaS3 cells by [(3)H]8-OH-DPAT and other serotonergic ligands.
[(3)H]8-OH-DPAT is a selective ligand for labeling 5-HT(1A) receptor sites. In competition binding experiments, we found that classic biogenic amine transporter inhibitors displaced [(3)H]8-OH-DPAT binding at its high-affinity binding sites in HeLaS3 cells. [(125)I]RTI-55 and [(3)H]paroxetine are known to specifically label amine transporter sites, and this was observed in our cells. Displacement studies showed that 8-OH-DPAT displayed affinity in a dose-dependent manner for the labeled amine transporter sites. These data suggest that [(3)H]8-OH-DPAT binds to amine uptake sites in HeLaS3 cells. A variety of drugs targeting different classes of receptors did not significantly affect [(3)H]8-OH-DPAT binding. Moreover, we determined the specific binding effects of various serotonergic ligands (i.e. [(125)I]cyanopindolol, [(3)H]ketanserin/[(3)H]mesulergine, [(3)H]GR-65630, [(3)H]GR-113808 and [(3)H]LSD) that specifically labeled 5-HT(1), 5-HT(2), 5-HT(3), 5-HT(4) and 5-HT(5-7) receptors, respectively. It is suggested that HeLaS3 cells contain distinct types of the related to 5-HT receptor recognition binding sites. These observations could help elucidate the relevant characteristics of different types of 5-HT receptors and 5-HT membrane transporters in tumor cells and their role in tumorigenesis.
Institute of Molecular and Cellular Biology, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan, ROC. jin-jye.feng@ricerca.com
Jin-Jye
JJ
Feng
Fong-Chi
FC
Cheng
Chun-Hsiung
CH
Lin
Jiann-Wu
JW
Wei
Shiaw-Der
SD
Yang
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000378:metabolism*; D001667:Binding, Competitive; D001679:Biogenic Amines / Q000378:metabolism; D003042:Cocaine / Q000031:analogs & derivatives / Q000378:metabolism; D005473:Fluoxetine / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008024:Ligands; D017374:Paroxetine / Q000378:metabolism; D011869:Radioligand Assay; D011985:Receptors, Serotonin / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000378:metabolism; D050492:Vesicular Biogenic Amine Transport Proteins / Q000037:antagonists & inhibitors
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D001679:Biogenic Amines; D003042:Cocaine; D005473:Fluoxetine; D008024:Ligands; D017374:Paroxetine; D011985:Receptors, Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors; D050492:Vesicular Biogenic Amine Transport Proteins; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane