Abstract:
:The effect of verapamil in a model system of A23187-induced Ca2+-uptake into liposomes was studied. This was done in order to separate the effects of verapamil on the lipid phase of membranes from its effects on membraneous proteins. In the absence of A23187, the liposomes exhibited a very low Ca2+ permeability, which did not change with addition of verapamil. Creation of a valinomycin-induced negative inside membrane potential combined with increased membrane permeability to Ca2+ (A23187), increased Ca2+-entry fivefold and more. Addition of verapamil under these conditions led to a further increase in Ca2+ entry. The negative inside polarization of the liposomes' membrane (as estimated from [3H]TPP+ uptake) was not affected by verapamil. [3H] Verapamil bound specifically to native synaptic plasma membranes with a Kd = 87.4 nM +/- 21.5 (SD) and Bmax = 2.19 pmol/mg protein +/- 0.92 (SD). Specific binding to the liposomes could not be demonstrated. High nonspecific binding of up to about 20% of the total verapamil in the external solution was observed (3.8 pmoles [3H]verapamil/mg phospholipid when 30 nM verapamil was used and 50 nmoles/mg phospholipid when 200 microM [3H] verapamil was used). The high nonspecific binding of verapamil to the liposomes had no detectable effect on the fluidity of their membrane, as seen in fluorescence-anisotropy studies with the fluorescent probe DPH.
journal_name
Biochem Pharmacoljournal_title
Biochemical pharmacologyauthors
Erdreich A,Rahamimoff Hdoi
10.1016/0006-2952(87)90237-1subject
Has Abstractpub_date
1987-06-01 00:00:00pages
1775-80issue
11eissn
0006-2952issn
1873-2968pii
0006-2952(87)90237-1journal_volume
36pub_type
杂志文章abstract::One feature that contraindicates the wide therapeutic use of retinoids is their teratogenicity. Synthetic retinoids are distinguishable from each other on the basis of their partial or exclusive preference in binding and activation of all-trans retinoic acid receptors (RARs) or retinoid X receptors (RXRs). Using mouse...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(95)00183-z
更新日期:1995-08-25 00:00:00
abstract::Sulfasalazine (SF) promotes remyelination and improves the outcome of multiple sclerosis (MS) patients. However, the underlining mechanism remains elusive. Here, we examined whether SF blocks microglia switching to a pro-inflammatory M1-like phenotype through a competing endogenous RNA (ceRNA) effects in cuprizone-ind...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/j.bcp.2018.06.028
更新日期:2018-09-01 00:00:00
abstract::LLC-PK(1) is a proximal tubular cell line derived from normal pig kidney which has a structure and function similar to those of renal proximal tubular cells and which expresses baseline levels of P-glycoprotein. We isolated by drug selection a doxorubicin-resistant cell line (LLC-PK(1)/ADR) that exhibited a multidrug-...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/s0006-2952(00)00535-9
更新日期:2001-01-01 00:00:00
abstract::When rat peritoneal leucocytes were incubated with carbon tetrachloride, a PLA2 was activated, eicosanoids were generated and lysosomal and cytoplasmic enzymes were released. The predominant eicosanoid generated was TXB2 with lesser amounts of PGE2, 6-keto PGF1 alpha and LTB4. Preincubation of the cells with two struc...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(85)90693-8
更新日期:1985-05-01 00:00:00
abstract::The effects of the basic polypeptide melittin on islet phospholipid degradation and insulin release were studied in static incubations of intact rat islets as a possible model of endogenous phospholipase A2 (PLA2) activation. Melittin (2 micrograms/ml) increased [3H]-arachidonic acid [( 3H]-AA) release from prelabeled...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(86)90438-7
更新日期:1986-10-01 00:00:00
abstract::The effect of the calcium channel blocker verapamil (VRP) on the accumulation and retention of vincristine (VCR) has been examined in mice bearing xenografts of human rhabdomyosarcomas. The tumors were Rh18, moderately sensitive to VCR, and its subline, Rh18/VCR3, selected in vivo for primary resistance to VCR. Admini...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(89)90405-x
更新日期:1989-06-01 00:00:00
abstract::Quinones are ubiquitously present in mammals and their environment. They are involved in physiologic functions such as electron transport but are also toxic compounds. In particular, quinone-quinol redox cycles may lead to oxidative stress, and arylating quinones have been demonstrated to activate endoplasmic reticulu...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/j.bcp.2011.12.006
更新日期:2012-04-01 00:00:00
abstract::Anaesthetized rabbits were used to study the effect of bromobenzene-induced hepatic damage to the acinar zone 3 on bile flow, bile salt, sodium secretion as well as bilirubin transport in basal conditions or with infusion of sodium glycodeoxycholate. The bromobenzene-pretreated animals exhibited in basal conditions a ...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(85)90181-9
更新日期:1985-02-15 00:00:00
abstract::The effect of oxygen concentration and Ca2+ omission on CCl4-induced hepatotoxicity was studied in a non-recirculating and hemoglobin-free liver perfusion system using phenobarbital-pretreated rats. With 95% O2-saturated perfusate, infusion of 0.5 mM CCl4 caused an instantaneous increase of thiobarbituric acid reactiv...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(90)90368-u
更新日期:1990-10-15 00:00:00
abstract::Pretreatment with sodium phenobarbital induces hepatic microsomal enzymes which are responsible for the metabolic breakdown of a large number of endogenous and exogenous chemical compounds. A previous study [K. P. DuBois and F. K. Kinoshita, Proc. Soc. exp. Biol. Med. 129, 699 (1968)] reported that phenobarbital pretr...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(83)90455-0
更新日期:1983-04-15 00:00:00
abstract::The constitutive androstane receptor (CAR) modulates the transcription of numerous genes involving drug metabolism, energy homeostasis, and cell proliferation. Most functions of CAR however were defined from animal studies. Given the known species difference of CAR and the significant cross-talk between CAR and the pr...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/j.bcp.2015.08.087
更新日期:2015-11-01 00:00:00
abstract::Spider venoms are replete with peptidic ion channel modulators, often with novel subtype selectivity, making them a rich source of pharmacological tools and drug leads. In a search for subtype-selective blockers of voltage-gated calcium (CaV) channels, we isolated and characterized a novel 39-residue peptide, ω-TRTX-C...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/j.bcp.2014.02.008
更新日期:2014-05-15 00:00:00
abstract::The thiopurines have a wide array of effects on purine metabolism, but the primary mechanism of cytotoxicity for both 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) appears to be incorporation of drug into DNA following conversion to the thioguanylate form. In murine leukemic cell lines exposed to a range of thiopur...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(93)90333-r
更新日期:1993-11-02 00:00:00
abstract::Coenzyme CoQ10 (CoQ10), a ubiquinone compound, has been reported to inhibit tyrosinase activity and melanin production in melanoma B16F10 cells. However, the molecular mechanism underlying this inhibitory effect is poorly understood. In this paper we aimed to investigate the molecular mechanisms involved in the anti-m...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/j.bcp.2019.04.015
更新日期:2019-06-01 00:00:00
abstract::Chronic administration to rats of the anticonvulsant drug, valproate, induced proliferation of liver peroxisomes and selectively increased the activity of the enzymes involved in beta-oxidation in these organelles. In kidney cortex, only a moderate increase in enzyme activity could be recorded. Valproate (1% w/w in th...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(91)90557-l
更新日期:1991-05-15 00:00:00
abstract::The stimulated uptake of 45Ca2+ into incubated cerebrocortical synaptosomes caused by veratrine (75 microM) was blocked by low concentrations of verapamil (0.5-30 microM) which did not prevent or reduce depolarization as judged by efflux of potassium (K+). However, verapamil did not prevent amino acid neutrotransmitte...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(85)90314-4
更新日期:1985-06-01 00:00:00
abstract::The inhibitory effects of N-(4-hydroxyphenyl)retinamide (HPR) and its glucuronide derivative on the growth of MCF-7 human breast cancer cells in vitro were compared. The results indicate that the glucuronide had slightly greater potency and much less cytotoxicity than the free retinoid. At a concentration of 10(-6) M,...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(91)90563-k
更新日期:1991-05-15 00:00:00
abstract::As theophylline, caffeine and acetaminophen (APAP) are commonly found in combination in prescription and non-prescription drugs, the present study was designed to evaluate changes of hepatic glutathione (GSH) and lipid peroxidation in rats treated concurrently with these widely used drugs. In rats treated with differe...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(94)90173-2
更新日期:1994-02-09 00:00:00
abstract::Administration of pentylenetetrazol (PTZ) (60 mg/kg, s.c.) to normal or carbaryl (200 mg/kg, p.o.) treated adult male albino rats produced characteristic changes in the steady-state levels of striatal dopamine (DA), noradrenaline (NA) and homovanillic acid (HVA) at different time intervals (0.5, 1.0 and 2.0 hr). The e...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(85)90189-3
更新日期:1985-02-15 00:00:00
abstract::The formyl peptide receptor (FPR) gene family has a complex evolutionary history and comprises eight murine members but only three human representatives. To enable translation of results obtained in mouse models of human diseases, more comprehensive knowledge of the pharmacological similarities/differences between the...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/j.bcp.2016.09.004
更新日期:2016-11-01 00:00:00
abstract::Ellipticine is a potent antineoplastic agent whose mechanism of action is considered to be based mainly on DNA intercalation and/or inhibition of topoisomerase II. Recently, we found that ellipticine also forms covalent DNA adducts and that the formation of the major adduct is dependent on the activation of ellipticin...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/s0006-2952(02)01072-9
更新日期:2002-07-15 00:00:00
abstract::Polychlorinated biphenyls (PCBs) induce drug metabolism that may lead to the bioactivation of PCBs themselves or alternatively may lead to oxidative events within the cell. The goal of the present study was to determine the influence of congeneric PCBs, selected as substrates for or inducers of drug metabolism, upon h...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/s0006-2952(01)00668-2
更新日期:2001-08-01 00:00:00
abstract::Arylamine N-acetyltransferase 1 (NAT1) conjugates several aromatic amines and their N-hydroxylated metabolites by N- or O-acetylation. NAT1 genotype and phenotype is known to be variable in human populations. In this study, we set out to measure the functional relevance of the frequent NAT1 gene variants for the activ...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/s0006-2952(99)00269-5
更新日期:1999-12-01 00:00:00
abstract::The inhibitory effect of a range of nitroimidazole-derivatives on H2 production by metronidazole resistant (CDC-85) and susceptible (C1-NIH) Trichomonas vaginalis strains was investigated. The 2-, 4-, and 5-nitro-derivatives used had one-electron reduction potentials within the range -250 to -525 mV. Nitroimidazole co...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(86)90327-8
更新日期:1986-05-15 00:00:00
abstract::Current evidence demonstrates that protein kinase C (PKC) belongs to a group of cell-signaling molecules that are sensitive targets for redox modifications and functional alterations that mediate oxidant-induced cellular responses. Our studies have demonstrated that diminished intracellular GSH was associated to inact...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/s0006-2952(03)00507-0
更新日期:2003-10-15 00:00:00
abstract::Disturbed redox homeostasis with both elevated reactive oxygen species (ROS) levels and antioxidant defense mechanisms has been reported in acute lymphoblastic leukemia (ALL). We therefore hypothesized that inhibition of pathways responsible for ROS detoxification renders ALL cells more susceptible for cell death. Her...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/j.bcp.2016.01.004
更新日期:2016-04-01 00:00:00
abstract::Bovine serum albumin (BSA) catalyzes the o-rearrangement of the reactive electrophile, N-sulfooxy-2-acetylaminofluorene (NSF), a potential ultimate hepatocarcinogen in the rat, to the nonmutagenic sulfuric acid esters of 1- and 3-hydroxy-2-acetylaminofluorene. Conversion of NSF was proportional to BSA concentrations r...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(89)90678-3
更新日期:1989-11-15 00:00:00
abstract::The mechanism for formation of high-affinity binding of 1-(2,6-dichlorobenzylidene-amino)-3-hydroxyguanidine (guanoxabenz) to alpha2-adrenoceptors was studied in particulate fractions from the rat spleen. The proportion of apparent high versus low-affinity alpha2-adrenoceptor binding sites increased with increasing in...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/s0006-2952(98)00135-x
更新日期:1998-11-01 00:00:00
abstract::The effect of the cationic dye, ruthenium red (RR), on ionic fluxes, Ca2+ signal generation, and stimulation of aldosterone production was studied in isolated rat adrenal glomerulosa cells. In these cells, increased extracellular [K+] as well as angiotensin II (Ang II) elevate cytoplasmic Ca2+ concentration and thereu...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/s0006-2952(98)00285-8
更新日期:1999-01-15 00:00:00
abstract::The mechanism by which the substituted benzimidazole sulphoxide BY 1023/SK&F 96022 inhibited the (H+ + K+)-ATPase, the enzyme responsible for hydrogen ion secretion in the stomach, was studied in a variety of in vitro preparations. In gastric preparations that were capable of active hydrogen ion transport with consequ...
journal_title:Biochemical pharmacology
pub_type: 杂志文章
doi:10.1016/0006-2952(90)90128-8
更新日期:1990-06-01 00:00:00