caa a22 4500 469078693 CHVBK 20180323132943.0 cr unu---uuuuu 170328e19920801xx s 000 0 eng 10.1007/BF00165293 doi (NATIONALLICENCE)springer-10.1007/BF00165293 Functional expression of human 5-HT1A receptors and differential coupling to second messengers in CHO cells [Elektronische Daten] [John Raymond, Frank Albers, John Middleton] Summary: The signal transduction linkages of the cloned human 5-HT1A receptor as expressed stably in CHO cells were studied. A transfected clonal cell line which expresses 900 ± 36 fmol 5-HT1A receptor/mg protein (designated CHO-5-HT1A/WT-27) responded to 5-HT and/or 8-OH-DPAT by coupling to several second messenger pathways. The 5-HT1A receptor inhibited, but did not stimulate, membrane adenylyl cyclase activity and whole cell cAMP accumulation in a dose-dependent manner (for 5-HT, IC50 = 146 ± 27 and 55 ± 12 nM, respectively). Activation of the receptor was associated with other signal transduction linkages: (i) a 40-50% increase in hydrolysis of inositol phosphates (for 5-HT, EC50 = 1.33 ± 0.15 μM for 5-HT), (ii) a transient elevation of cytosolic Ca2+ levels (apparent at 1-100 μM 5-HT) which was not affected by chelation of extracellular Ca2+ by EGTA, and (iii) an augmentation of [3H]-arachidonic acid release pharmacologically with the calcium ionophore A23187 or by activation of endogenous thrombin or P2 purinergic receptors (for 5-HT, EC50 = 1.22 ± 0.17 μM). This pathway may be an amplification mechanism for signaling in anatomic regions with high concentrations of several neuro-transmitters, hormones or autacoids, such as at neuronal junctions or near areas of platelet aggregation. All linkages were sensitive to pertussistoxinpre-treatment (IC50≈0.5-0.6 ng/ml × 4.5 h for all pathways), suggesting the involvement of Gi protein(s) in these signal transduction pathways. Coupling to varied signal transduction pathways in a single cell system may be a common feature of receptors which classically inhibit adenylyl cyclase such as the 5-HT1A receptor. Springer-Verlag, 1992 Serotonin receptor nationallicence Transfection nationallicence CHO cell nationallicence G protein nationallicence Adenylyl cyclase nationallicence Arachidonic acid nationallicence cAMP : adenosine 3′,5′-cyclic monophosphate nationallicence PKC : protein kinase C (calcium and phospholipid-dependent kinase) nationallicence 5-HT : serotonin nationallicence 8-OH-DPAT : 8-OH-2-(di-n-propylamino)1,2,3,4-tetrahydronaphthalene nationallicence PBS : phosphate buffered saline nationallicence EDTA : ethylenediaminetetraacetic acid nationallicence BSA : bovine serum albumin nationallicence Hepes : N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid nationallicence CHAPS : 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfate nationallicence [125I]-N3-NAPS : N-(p-azido-m-[125I]iodophenethyl)-spiperone nationallicence G protein : (guanine nucleotide binding protein) nationallicence mCPP : 1-(3-chlorophenyl)piperazine nationallicence TFMPP : m-trifluoromethylphenyl-piperazine nationallicence PAPP (LY-165,163) : p-aminophenylethyl-m-trifluoromethylphenyl piperazine nationallicence m CPP : 1-(3-chlorophenyl)piperazinedihydrochloride nationallicence WB 4101 : 2-(2,6-dimethoxyphenoxyethyl)aminoethyl1,4-benzodioxane hydrochloride nationallicence NAN-190 : 1-(2-methoxyphenyl)-4-(2-phthalimido)butyl]piperazine nationallicence H-7 : 1-(5-isoquinolinesulfonyl)-2-methylpiperazine nationallicence SDS-PAGE : sodium dodecyl sulfate-polyacrylamide gel electrophoresis nationallicence Raymond John Department of Medicine (Nephrology), Duke University Medical Center, 27710, Durham, NC, USA aut Albers Frank Department of Medicine (Nephrology), Duke University Medical Center, 27710, Durham, NC, USA aut Middleton John Department of Medicine (Nephrology), Duke University Medical Center, 27710, Durham, NC, USA aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/2(1992-08-01), 127-137 0028-1298 346:2<127 1992 346 210 https://doi.org/10.1007/BF00165293 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00165293 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Raymond John Department of Medicine (Nephrology), Duke University Medical Center, 27710, Durham, NC, USA aut NATIONALLICENCE 700 1- Albers Frank Department of Medicine (Nephrology), Duke University Medical Center, 27710, Durham, NC, USA aut NATIONALLICENCE 700 1- Middleton John Department of Medicine (Nephrology), Duke University Medical Center, 27710, Durham, NC, USA aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/2(1992-08-01), 127-137 0028-1298 346:2<127 1992 346 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer