Abstract:
:Lead (Pb(2+)) is a well-known inhibitor of voltage-dependent Ca(2+) channels in their native environments in several types of cells. However, its effects on discrete Ca(2+) channel phenotypes in isolation have not been well studied. We compared how specific subtypes of human neuronal high-voltage-activated Ca(2+) channels were affected by acute exposure to Pb(2+). Expression cDNA clones of human alpha(1C), alpha(1B), or alpha(1E) subunit genes encoding neuronal L-, N-, and R-subtypes of Ca(2+) channels, respectively, along with a constant alpha(2)delta and beta(3) subunits were transfected into human embryonic kidney 293 cells. Currents through the respective transiently expressed channels were measured using whole-cell recording techniques with Ba(2+) (20 mM) as charge carrier. Extracellular bath applications of Pb(2+) significantly reduced current amplitude through all three types of Ca(2+) channels in a concentration-dependent manner. The order of potency was: alpha(1E) (IC(50) = 0.10 microM), followed by alpha(1C) (IC(50) = 0.38 microM) and alpha(1B) (IC(50) = 1.31 microM). Pb(2+)-induced perturbation of function of alpha(1C) and alpha(1B) containing Ca(2+) channels was more easily reversed than for alpha(1E)-containing Ca(2+) channels after washing with Pb(2+) free solution. The current-voltage relationships were not altered after 3-min exposure to Pb(2+) for any of the three types. However, the steady-state inactivation relationships were shifted to more negative potentials for channels containing alpha(1B) and alpha(1E) subunits, but not for those containing alpha(1C) subunits. Pb(2+) accelerated the inactivation time of current in all three subtypes of Ca(2+) channels in a concentration- and voltage-dependent manner. Therefore, different subtypes of Ca(2+) channels exhibit differential susceptibility to Pb(2+) even when expressed in the same cell type. Current expressed by alpha(1E)-containing channels is more sensitive to Pb(2+) than that expressed by alpha(1C)- or alpha(1B)-containing channels. Several Ca(2+) channel phenotypes are quite sensitive to the inhibitory action of Pb(2+). Furthermore, it seems that Pb(2+) is more likely to combine with Ca(2+) channels in the closed state.
journal_name
Mol Pharmacoljournal_title
Molecular pharmacologyauthors
Peng S,Hajela RK,Atchison WDdoi
10.1124/mol.62.6.1418keywords:
subject
Has Abstractpub_date
2002-12-01 00:00:00pages
1418-30issue
6eissn
0026-895Xissn
1521-0111journal_volume
62pub_type
杂志文章abstract::The human CYP2C9 plays a crucial role in the metabolic clearance of a wide range of clinical therapeutics. The *2 allele is a prevalent genetic variation in CYP2C9 that is found in various populations. A marked reduction of catalytic activity toward many important drug substrates has been demonstrated by CYP2C9*2, whi...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/molpharm.120.000042
更新日期:2020-11-01 00:00:00
abstract::We have investigated various nitric oxide (NO) synthase inhibitors for their affinity and selectivity toward the three human isoenzymes in radioligand binding experiments. Therefore, we developed the new radioligand [(3)H]2-amino-4-picoline to measure binding of these compounds to the three human NO synthase (NOS) iso...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:2000-11-01 00:00:00
abstract::Our laboratory recently isolated and sequenced cDNAs encoding the microsomal flavin-containing monooxygenases (FMOs) from rabbit liver and rabbit lung. As a first step in understanding the molecular bases for the catalytic and physical differences between these enzymes, we have expressed them in COS-1 cells and compar...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1991-11-01 00:00:00
abstract::Recent reports regarding the significance of chemokine receptors in disease have put a spotlight on atypical chemokine receptor 3 (ACKR3). This atypical chemokine receptor is overexpressed in numerous cancer types and has been involved in the modulation of tumor cell proliferation and migration, tumor angiogenesis, or...
journal_title:Molecular pharmacology
pub_type: 杂志文章,评审
doi:10.1124/mol.118.115279
更新日期:2019-12-01 00:00:00
abstract::Healing of gastrointestinal mucosal lesions occurs through two processes: an early one involving cell migration and a later one in which cell division replaces lost cells. Both processes require the presence of polyamines, but the mechanism of action of these compounds is unknown. In the present study, we examined the...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1995-10-01 00:00:00
abstract::Reuptake of glutamate in astrocytes, a critical mechanism involved in the maintenance of physiological excitatory amino acid neurotransmission, is inhibited by both arachidonic acid (AA) and reactive oxygen species (ROS), via incompletely defined molecular mechanisms. Because ROS are generated during AA metabolism and...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1994-11-01 00:00:00
abstract::In order to elucidate the key atoms and/or stereostructures necessary for the inhibitory emergence of aldose reductase, crystal structure determinations were carried out for 11 oxazolecarbamate analogues, which have similar chemical and physicochemical properties but different inhibitory activities. The molecular conf...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1988-09-01 00:00:00
abstract::The effect of the neuromuscular blocker alcuronium on the binding of N-[3H]-methylscopolamine [( 3H]NMS) and l-[3H]quinuclidinylbenzilate ([3H]QNB) to muscarinic binding sites in rat heart atria, longitudinal smooth muscle of the ileum, cerebral cortex, cerebellum, and submaxillary glands was measured using filtration...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1990-11-01 00:00:00
abstract::The effect of ethanol on intracellular ionized calcium concentrations (Cai) was studied in synaptosomes isolated from mouse whole brain and in hepatocytes isolated from rat liver. The fluorescent calcium chelator, fura-2, was used to quantitate Cai. Incubation of synaptosomes with ethanol (350-700 mM) increased restin...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1987-12-01 00:00:00
abstract::We reported previously that protein associated with Myc (PAM) interacts with the C2 domain of type V adenylyl cyclase (ACV-C2) and that purified PAM is a potent inhibitor of Galphas-stimulated ACV activity (J Biol Chem 276:47583-47589, 2001). The present study was conducted to identify the region in PAM that inhibits ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.104.005355
更新日期:2005-01-01 00:00:00
abstract::The mouse 5-hydroxytryptamine4a (5-HT4a) receptor is an unusual member of the G protein-coupled receptor superfamily because it possesses two separate carboxyl-terminal palmitoylation sites, which may allow the receptor to adopt different conformations in an agonist-dependent manner (J Biol Chem 277:2534-2546, 2002). ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.104.008748
更新日期:2005-05-01 00:00:00
abstract::To investigate the roles of individual transmembrane segments (TM) of the human D3 dopamine receptor in its ligand-receptor interactions, we generated chimeric receptors in which its TMs were replaced, one at a time, partially or entirely, by the corresponding TM of the homologous human D1 receptor. Ligand binding pro...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.54.2.379
更新日期:1998-08-01 00:00:00
abstract::Up-regulation of fractalkine is involved in vascular and tissue damage in inflammatory conditions. Resveratrol has been shown to have anti-inflammatory, antioxidant, and antitumor activities. Its regulatory effects on expression of fractalkine in vascular endothelial cells and fractalkine receptor CX3CR1 in monocytes ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.106.022392
更新日期:2006-07-01 00:00:00
abstract::Effects of pimaric acid (PiMA) and eight closely related compounds on large-conductance K(+) (BK) channels were examined using human embryonic kidney (HEK) 293 cells, in which either the alpha subunit of BK channel (HEKBKalpha) or both alpha and beta1 (HEKBKalphabeta1) subunits were heterologously expressed. Effects o...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.62.4.836
更新日期:2002-10-01 00:00:00
abstract::The effect of endocytosis inhibitors on 5-hydroxytryptamine(2A) (5-HT(2A)) receptor desensitization and resensitization was examined in transiently transfected human embryonic kidney (HEK) 293 cells and in C6 glioma cells that endogenously express 5-HT(2A) receptors. In HEK-293 cells, 5-HT(2A) receptor desensitization...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.60.5.1020
更新日期:2001-11-01 00:00:00
abstract::Low-density lipoprotein (LDL) is known to be a mitogenic factor for vascular smooth muscle cells (VSMCs), fibroblasts, and endothelial cells. In the current study, we describe possible intracellular mechanisms by which LDL elicits its mitogenic effects. Stimulation of VSMCs with LDL resulted in a pertussis-toxin (PTX)...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.52.3.389
更新日期:1997-09-01 00:00:00
abstract::Stimulation of beta2-adrenoceptors with the selective beta2 agonist procaterol caused a biphasic decrease in cell surface M2 muscarinic receptor number in human embryonic lung 299 cells when measured with the hydrophilic antagonist [3H]N-methylscopolamine. In contrast, total muscarinic receptor number, measured with t...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1996-04-01 00:00:00
abstract::The alpha2-adrenergic receptors (alpha2-ARs) mediate signals to intracellular second messengers via guanine nucleotide binding proteins. Three human genes encoding alpha2-AR subtypes (alpha2A, alpha2B, alpha2C) have been cloned. Several chemical compounds display subtype differences in their binding and/or functional ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.53.3.370
更新日期:1998-03-01 00:00:00
abstract::The catestatin fragment of chromogranin A is an endogenous inhibitor of nicotinic cholinergic transmission, functioning in negative feedback control of catecholamine secretion. We explored naturally occurring polymorphisms in the amino acid sequence of catestatin. Three human variants were identified: Gly364Ser, Pro37...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.104.002139
更新日期:2004-11-01 00:00:00
abstract::The nuclear pregnane X receptor (PXR) and constitutive androstane receptor (CAR) play central roles in protecting the body against environmental chemicals (xenobiotics). PXR and CAR are activated by a wide range of xenobiotics and regulate cytochrome P450 and other genes whose products are involved in the detoxificati...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.62.3.638
更新日期:2002-09-01 00:00:00
abstract::The structure-activity relationships for vasoactive intestinal peptide (VIP) receptor binding were studied using N-terminally modified VIP analogs. VIP fragments, and VIP receptor antagonists. Tissue sources included bovine coronary artery, rat mesenteric artery, rat pituitary, rat brain synaptosomes, and rat liver. E...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1990-06-01 00:00:00
abstract::The seven-transmembrane receptor Smoothened (Smo) is the major component involved in signal transduction of the Hedgehog (Hh) morphogens. Smo inhibitors represent a promising alternative for the treatment of several types of cancers linked to abnormal Hh signaling. Here, on the basis of experimental data, we generated...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.110.065102
更新日期:2010-10-01 00:00:00
abstract::A collection of analogues of atrial natriuretic peptide (ANP) were screened for their ability to inhibit ANP-induced cGMP stimulation. The antagonists revealed through this screen are structurally related; almost all are substituted at either aspartate-13 or phenylalanine-26. This tendency is consistent throughout sev...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1990-12-01 00:00:00
abstract::Several 2-amino-3-benzoylthiophenes were found to increase the binding of [3H]N6-cyclohexyladenosine to A1 adenosine receptors in rat brain membranes. Concentration-response curves were bell-shaped, with up to 45% stimulation of binding at 10 microM followed by inhibition at higher concentrations. Because these compou...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1990-12-01 00:00:00
abstract::TNP-ATP has become widely recognized as a potent and selective P2X receptor antagonist, and is currently being used to discriminate between subtypes of P2X receptors in a variety of tissues. We have investigated the ability of TNP-ATP to inhibit alpha,beta-methylene ATP (alpha,beta-meATP)-evoked responses in 1321N1 hu...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.58.6.1502
更新日期:2000-12-01 00:00:00
abstract::We describe here the cloning and characterization of a rat homolog of the chemokine receptor CXCR3. The predicted amino acid sequence of rat CXCR3 contains 367 amino acid residues, sharing 96 and 87% amino acid sequence identity to the murine and human CXCR3, respectively. Among a large panel of chemokines tested, onl...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:2000-06-01 00:00:00
abstract::The role of protein kinase C (PKC) in the human aryl hydrocarbon receptor (hAhR) signal transduction pathway was examined in cell lines stably transfected with pGUDLUC6.1, in which luc+ is solely controlled by four dioxin-responsive elements (DREs). These cell lines, P5A11 and HG40/6, were derived from HeLa and HepG2 ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.53.4.691
更新日期:1998-04-01 00:00:00
abstract::The use of classic antipsychotic drugs is limited by the occurrence of extrapyramidal motor symptoms, which are caused by dopamine (DA) receptor blockade in the neostriatum. We examined the impact of early-life stress on haloperidol-induced catalepsy using the rat model of prenatal restraint stress (PRS). Adult "PRS r...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.113.085530
更新日期:2013-08-01 00:00:00
abstract::In the human lymphocyte, desensitization of the beta-adrenergic receptor-adenylate cyclase complex is associated with sequestration of the receptor as well as a change in photolabeling of beta-receptor proteins. Thus, desensitization of the lymphocyte beta-adrenergic receptor-adenylate cyclase system is associated wit...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1986-11-01 00:00:00
abstract::Cytotoxic effects of quinones are thought to be mediated by redox cycles between quinones and quinols whereby reactive oxygen species are generated. The role of glucuronidation in preventing these toxic redox cycles was investigated by using benzo(a)pyrene-3,6-quinone and isolated rat hepatocytes or Reuber hepatoma ce...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1985-04-01 00:00:00