Abstract:
:We have expanded previous studies with the 5-hydroxytryptamine (5-HT)(2) receptor agonist (+/-)-1-(2,5-dimethoxy-4-[(125)I]iodophenyl)-2-aminopropane [(+/-)-[(125)I]DOI] in human brain that had shown biphasic competition curves for several 5-HT(2A) receptor antagonists by using new selective antagonists of 5-HT(2A) (MDL100,907) and 5-HT(2C) (SB242084) receptors together with ketanserin and mesulergine. Autoradiographic competition experiments were performed with these antagonists in human brain regions where (+/-)-[(125)I]DOI labels almost exclusively 5-HT(2A) receptors (frontal cortex and striosomes). Furthermore, the effect of uncoupling receptor/G protein complexes on antagonist competition was studied with guanosine-5'-(beta,gamma-imido)triphosphate [Gpp(NH)p]. Competition experiments with (+/-)-[(3)H]1-(4-bromo-2,5-dimethoxyphenil)-2-aminopropane [(+/-)-[(3)H]DOB] were also performed in membranes from Chinese hamster ovary cells (CHOFA4) expressing cloned human 5-HT(2A) receptors. In both systems, ketanserin and MDL100,907 displayed biphasic competition profiles, whereas SB242084 and mesulergine competed monophasically. In absence of antagonist, 100 microM Gpp(NH)p decreased brain (+/-)-[(125)I]DOI specific binding by 40 to 50% and (+/-)-[(3)H]DOB specific binding to CHOFA4 cells by 30%. The remaining agonist-labeled uncoupled sites were still displaced biphasically by ketanserin and MDL100,907, with unaltered affinities. Saturation experiments were performed in CHOFA4 cells. (+/-)-[(3)H]DOB labeled two sites (K(d(h))= 0.8 nM, K(d(l)) = 31.22 nM). Addition of 100 microM Gpp(NH)p resulted in a single low-affinity (K(d) = 24.44 nM) site with unchanged B(max). [(3)H]5-HT showed no specific binding to 5-HT(2A) receptors. These results conform with the extended ternary complex model of receptor action that postulates the existence of partly activated receptor conformation(s) (R*) in equilibrium with the ground (R) and the activated G protein-coupled (R*G) conformations. Thus, both in human brain and CHOFA4 cells, the agonists possibly label all three conformations and ketanserin and MDL100,907 recognize with different affinities at least two of these conformations.
journal_name
Mol Pharmacoljournal_title
Molecular pharmacologyauthors
López-Giménez JF,Villazón M,Brea J,Loza MI,Palacios JM,Mengod G,Vilaró MTkeywords:
subject
Has Abstractpub_date
2001-10-01 00:00:00pages
690-9issue
4eissn
0026-895Xissn
1521-0111journal_volume
60pub_type
杂志文章abstract::Undesired block of human ERG1 potassium channels is the basis for cardiac side effects of many different types of drugs. Therefore, it is important to know exactly why some drugs particularly bind to these channels with high affinity. Upon expression in mammalian cells and Xenopus laevis oocytes, we investigated the i...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.65.5.1120
更新日期:2004-05-01 00:00:00
abstract::Previous studies have demonstrated that the quinone group may play an important role in modulating the alkylating activity of quinone alkylating agents. Introduction of a quinone moiety markedly increased the alkylating activity and cytotoxic activity of the model quinone alkylating agents benzoquinone mustard and ben...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1991-09-01 00:00:00
abstract::The effects of 5-hydroxytryptamine (5-HT)2A receptor activation on cAMP formation were studied in a cell line derived from embryonic rat cortex (A1A1). 5-HT (EC50 = 0.87 microM) amplified the amount of cAMP formed in response to 5'-N-ethylcarboxamidoadenosine (an adenosine A2 receptor agonist), cholera toxin, and fors...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1994-05-01 00:00:00
abstract::Cardiac-directed expression of AC6 has pronounced favorable effects on cardiac function possibly not linked with cAMP production. To determine rigorously whether cAMP generation is required for the beneficial effects of increased AC6 expression, we generated a catalytically inactive AC6 mutant (AC6mut) that has marked...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.110.067298
更新日期:2011-03-01 00:00:00
abstract::A recently developed stable isotope dilution liquid chromatography-multiple reaction/mass spectrometry method to quantify focal adhesion kinase (FAK) activation loop phosphorylation was used to study endogenous Src kinase activity. This revealed that bis-phosphorylated pTyr(576)/Tyr(577)-FAK was a biomarker of Src act...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.108.052464
更新日期:2009-03-01 00:00:00
abstract::Circular RNAs (circRNAs) are a distinct category of single-stranded, covalently closed RNAs formed by backsplicing. The functions of circRNAs are incompletely known and are under active investigation. Here, we report that in addition to traditional linear mRNAs (linRNA), mouse, rat, and human opioid receptor genes gen...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.118.113977
更新日期:2019-08-01 00:00:00
abstract::Large conductance, Ca(2+)-activated K+ channels are believed to underlie interburst intervals and, thus, contribute to the control of hormone release from neurohypophysial terminals. Because ethanol inhibits the release of vasopressin and oxytocin, we studied its effects on large conductance, Ca(2+)-activated K+ chann...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1996-01-01 00:00:00
abstract::Seven transmembrane G protein-coupled receptors (GPCRs) are often phosphorylated at the C terminus and on intracellular loops in response to various extracellular stimuli. Phosphorylation of GPCRs by GPCR kinases and certain other kinases can promote the recruitment of arrestin molecules. The arrestins critically regu...
journal_title:Molecular pharmacology
pub_type: 杂志文章,评审
doi:10.1124/mol.116.107839
更新日期:2017-09-01 00:00:00
abstract::The relationship between the phospholipase-stimulating and immunosuppressive properties of cyclosporin A (CsA) has been investigated in vitro. At concentrations of 0.025 microM and upwards, CsA caused dose-related inhibition of both mitogen- and alloantigen-stimulated uptake of tritiated thymidine by human mononuclear...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1993-09-01 00:00:00
abstract::Trypanosoma brucei encodes a relatively high number of genes of the equilibrative nucleoside transporter (ENT) family. We report here the cloning and in-depth characterization of one T. brucei brucei ENT member, TbNT9/AT-D. This transporter was expressed in Saccharomyces cerevisiae and displayed a uniquely high affini...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.106.031559
更新日期:2007-03-01 00:00:00
abstract::Noscapine, a microtubule-interfering agent, has been shown to arrest mitosis, to induce apoptosis, and to have potent antitumor activity. We report herein that two brominated derivatives of noscapine, 5-bromonoscapine (5-Br-nosc) and reduced 5-bromonoscapine (Rd 5-Br-nosc), have higher tubulin binding activity than no...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.63.4.799
更新日期:2003-04-01 00:00:00
abstract::A novel cloned polymorphism of the human concentrative nucleoside transporter hCNT3 was described and functionally characterized. This variant consists of a T/C transition leading to the substitution of cysteine 602 by an arginine residue in the core of transmembrane domain 13. The resulting hCNT3(C602R) protein has t...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.107.041848
更新日期:2008-02-01 00:00:00
abstract::A number of different agonists activate G protein-coupled receptors to stimulate adenylyl cyclase (AC), increase cAMP formation, and promote relaxation in vascular smooth muscle. To more fully understand this stimulation of AC, we assessed the expression, regulation, and compartmentation of AC isoforms in rat aortic s...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.62.5.983
更新日期:2002-11-01 00:00:00
abstract::As noted previously, in N1E-115 neuroblastoma cells, carbamylcholine, a muscarinic cholinergic agonist, increased cGMP over 15-fold and decreased basal and prostaglandin E1 (PGE1)-stimulated cAMP content. In contrast to the stimulatory effects of PGE1 on cAMP, which were immediate, the carbamylcholine-induced decrease...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1985-08-01 00:00:00
abstract::The therapeutic potential of antitumor drugs is seriously limited by the manifestation of cellular drug resistance. We used the budding yeast Saccharomyces cerevisiae as a model system to identify novel mechanisms of resistance to one of the most active anticancer agents, cisplatin. We pinpointed NPR2 (nitrogen permea...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.64.2.259
更新日期:2003-08-01 00:00:00
abstract::G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs) act in concert to regulate cell growth, proliferation, survival, and migration. Metabotropic GABAB receptor (GABABR) is the GPCR for the main inhibitory neurotransmitter GABA in the central nervous system. Increased expression of GABABR has been ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.116.107854
更新日期:2017-09-01 00:00:00
abstract::Glucocorticoid-induced tumor necrosis factor receptor-related (GITR) protein is a costimulatory molecule that plays a role in inflammation so that GITR-Fc fusion protein can exert an anti-inflammatory effect. To investigate the mechanism by which GITR-Fc exerts its effects, we first used GITR knock-out (GITR(-/-)) mic...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.107.044354
更新日期:2008-06-01 00:00:00
abstract::Nitric oxide (NO) possesses potent anti-inflammatory properties; however, an over-production of NO will promote inflammation and induce cell and tissue dysfunction. Thus, the ability to precisely regulate NO production could prove beneficial in controlling damage. In this study, advantage was taken of the well charact...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.59.4.939
更新日期:2001-04-01 00:00:00
abstract::The midbrain periaqueductal gray (PAG) is involved in organizing behavioral responses to threat, stress, and pain. These PAG functions are modulated by cholinergic agents. In the present study, we examined the cholinergic modulation of synaptic transmission in the PAG using whole-cell voltage-clamp recordings from rat...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.108.045872
更新日期:2008-11-01 00:00:00
abstract::Cytosolic sulfotransferase 1C3 (SULT1C3) is the least characterized of the three human SULT1C subfamily members. Originally identified as an orphan SULT by computational analysis of the human genome, we recently reported that SULT1C3 is expressed in human intestine and LS180 colorectal adenocarcinoma cells and is upre...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.116.106005
更新日期:2016-11-01 00:00:00
abstract::We investigated the roles of cyclic GMP and cyclic AMP in the inhibition of rabbit platelet aggregation and degranulation by two nitrovasodilators, sodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1; the active metabolite of molsidomine), with particular reference to the synergistic interaction of these dru...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1990-05-01 00:00:00
abstract::The intracellular pathways taken by galactose-terminal glycoproteins were examined following endocytosis by the asialoglycoprotein receptor in monolayers of the human hepatoma cell line, Hep G2. In addition to a pathway leading to lysosomal degradation, single cohort kinetics revealed that up to 28% of surface-bound a...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1984-11-01 00:00:00
abstract::The ligand-binding sites of many G protein-coupled receptors (GPCRs) are situated around and deeply embedded within the central pocket formed by their seven transmembrane-spanning α-helical domains. Generally, these binding sites are assumed accessible to endogenous ligands from the aqueous phase. Recent advances in t...
journal_title:Molecular pharmacology
pub_type: 杂志文章,评审
doi:10.1124/mol.118.115113
更新日期:2019-11-01 00:00:00
abstract::Iodonium inhibition of the flavoenzymes neutrophil NADPH oxidase and cytochrome P450 reductase has been suggested to require reductive metabolism of the inhibitor to a phenyl radical. Inhibition would ultimately result from covalent attachment of phenyl radicals to either the flavin cofactor or adjacent amino acid sid...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1994-10-01 00:00:00
abstract::Advances in proteomic methodologies based on quantitative mass spectrometry are now transforming pharmacology and experimental biology more broadly. The present review will discuss several examples, based on work in the author's laboratory that focuses on delineating relationships between GPCR signaling and traffickin...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/molpharm.120.000178
更新日期:2020-12-22 00:00:00
abstract::Voltage-gated potassium (Kv) channels regulate many physiological functions and represent important therapeutic targets in the treatment of several clinical disorders. Although some of these channels have been well-characterized, the study of others, such as Kv3 channels, has been hindered because of limited pharmacol...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.105.011064
更新日期:2005-05-01 00:00:00
abstract::Previous studies suggest that selective antagonists of specific subtypes of muscarinic acetylcholine receptors (mAChRs) may provide a novel approach for the treatment of certain central nervous system (CNS) disorders, including epileptic disorders, Parkinson's disease, and dystonia. Unfortunately, previously reported ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.109.056531
更新日期:2009-08-01 00:00:00
abstract::Neurotrophins are a family of secreted proteins that play an important role in the development, differentiation, and survival of neurons. Studies also suggest that aberrant neurotrophin signaling may play a role in processes underlying disease states such as schizophrenia, Alzheimer's disease, and depression. Whereas ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.105.020255
更新日期:2006-04-01 00:00:00
abstract::The 90-kDa heat shock family (HSP90) of protein and two-component histidine kinases, although quite distinct at the primary amino acid sequence level, share a common structural ATP-binding domain known as the Bergerat fold. The Bergerat fold is important for the ATPase activity and associated chaperone function of HSP...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.62.2.289
更新日期:2002-08-01 00:00:00
abstract::The anticancer agent 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) and its methyl ester (CDDO-Me) typically induce a broad spectrum of growth-inhibitory, proapoptotic, and antiangiogenic responses. Treatment of Panc1, Panc28, and L3.6pL pancreatic cancer cells with low micromolar concentrations of CDDO or CDDO-...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.110.064451
更新日期:2010-08-01 00:00:00