Abstract：
:Opioid mu-receptors are membrane bound receptors. The mechanism by which they transduce their biological effect into the inner compartment of the postsynaptic cell is still not fully understood. The present study was attempted to the measurement of changes of the thermodynamic parameters of the receptor--agonist/antagonist interaction. We have set up the binding assays of a mu-receptor agonist (3H-dihydromorphine) as well as an antagonist (3H-naloxone). The saturation isotherms of both ligands have been assayed at various temperatures and from the resulting KD values the standard changes of Gibbs energy, enthalpy and entropy have been calculated. While the binding of the mu-receptor agonist 3H-dihydromorphine appears to be entropy driven (delta S0 = 230 J mol-1 K-1) and endothermic (delta H0 = 19 kJ mol-1), the binding of the mu-receptor antagonist 3H-naloxone is apparently driven by a decrease of standard enthalpy (delta H0 = -27 kJ mol-1; i.e. the reaction is exothermic) and is also characterized by an increase of standard entropy (delta S0 = 76 J mol-1 K-1). The maximal number of 3H-naloxone binding sites has to be determined by incubation at 0-4 degrees C. The present data to not support the view that opioid mu-receptors transduce their biological signal through the adenylatecyclase system by a mechanism similar to beta-adrenergically stimulated adenylatecyclase.
journal_name
Gen Physiol Biophysjournal_title
General physiology and biophysicsauthors
Zeman P,Tóth G,Kvetnanský Rsubject
Has Abstractpub_date
1987-06-01 00:00:00pages
237-48issue
3eissn
0231-5882issn
1338-4325journal_volume
6pub_type
杂志文章abstract：:Malfunction of skeletal muscles and dysregulated turnover of sphingolipids in the insulin responsive tissues have been determined at old age. Present article investigates the role of acid sphingomyelinase (SMase)-dependent ceramide accumulation in reduction of the skeletal muscle sensitivity to insulin action at old a...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017020
更新日期：2018-03-01 00:00:00
abstract：:The aim of this paper was to study the protein remodelling of the left ventricle following repeated administration of either daunorubicin (DNR) or DNR in combination with the cardioprotective agent dexrazoxane (DXZ). The experiment was carried out on three groups of Chinchilla male rabbits: 1. DNR (3 mg/kg i.v.), 2. D...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2003-09-01 00:00:00
abstract：:Sleep is considered as a physiological regulator in the body. Gamma-aminobutyric acid (GABA) is a neurotransmitter that modulates sleep and affects cardiac functions. We evaluated effects of acute sleep deprivation (SD) on cardiac hemodynamic parameters, expression of pro-inflammatory cytokines, and Heat shock protein...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017049
更新日期：2018-05-01 00:00:00
abstract：:Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted from intestinal L cells upon nutrients ingestion, and is currently used for treating diabetes mellitus. It plays an important role in receptor modulation and cross talk with insulin at the coronary endothelium (CE) and cardiomyocytes (CM) in diabetic type...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2011_01_34
更新日期：2011-03-01 00:00:00
abstract：:Apoptosis (programmed cell death) is an important process participating in the formation of organs and tissues during embryogenesis. Our aim of the work is studying the role of the apoptosis during the human embryonic differentiation. We tend to give acquired findings into the correlation with expression of proteins B...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1999-12-01 00:00:00
abstract：:Effects of six thiol reagents with different physico-chemical properties were tested on the Na+-dependent 45Ca2+ transport into the rat brain microsomal membrane vesicles. The mercurials p-chlormercuribenzoate and Mersalyl effectively inhibited 45Ca2+ uptake with IC50 values in the order of 10(-4) mol X l-1 in the med...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1987-04-01 00:00:00
abstract：:Changes in the Young elasticity modulus in perpendicular direction to the membrane surface E perpendicular, in the coefficient of dynamic viscosity eta, in the electric capacitance C, in the surface charge U1, in the conductivity g and in the coefficient of non-linearity beta of current-voltage characteristic caused b...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1987-04-01 00:00:00
abstract：:Tissue intermittent hypoxia (IH) occurs in obstructive sleep apnea, sickle cell anemia, physical exercise and other conditions. Poor gas solubility and slow diffusion through culture media hampers mimicking IH-induced transitions of O(2) in vitro. We aimed to develop a system enabling exposure of cultured cells to IH ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2014043
更新日期：2015-07-01 00:00:00
abstract：:The left and right ventricles fulfill different role in heart function. Here we compare chamber specific changes in local catecholamine concentrations; gene expression and the receptor protein amount of all three β-adrenoceptors (β-AR) in rat right heart ventricles exposed to acute (1 session) and repeated (7 sessions...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2014002
更新日期：2014-01-01 00:00:00
abstract：:The effects of pentoxifylline (PTX) on intracellular accumulation of doxorobicin (DOX), DOX cytotoxicity and expression of Pgp in multidrug resistant L1210/VCR cell line were investigated. PTX (100 mg/l) was able to enhance the DOX accumulation in resistant cells. The maximum intracellular levels of DOX were reached a...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2002-03-01 00:00:00
abstract：:Quercetin and epigallocatechin gallate are two of the most abundant polyphenols in dietary plants, including apples, onions, red wine and green tea. The bioactivity of polyphenols is linked to their ability to interact with cell membranes without being internalized. The aim of the present study was to assess the short...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2012_005
更新日期：2012-03-01 00:00:00
abstract：:The hormone leptin, by binding to hypothalamic receptors, suppresses food intake and decreases body adiposity. Leptin receptors are also widely expressed in extra-hypothalamic areas such as hippocampus, amygdala and cerebellum, where leptin modulates synaptic transmission. Here we show that a defective leptin receptor...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2013056
更新日期：2014-01-01 00:00:00
abstract：:Fusion of neuraminidase or trypsin pretreated human erythrocytes and untreated cells was performed. The obtained doublets had a permanent dipole moment which disappeared as a function of time. Since the dipole moment disappearance is due to protein interdiffusion the lateral diffusion constant may be determined. This ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1984-06-01 00:00:00
abstract：:The effect of binding of an antitumour drug cis-diamminedichloroplatinum(II) (cis-[Pt(NH3)2Cl2]) to DNA on cutting effectiveness of BamHI, EcoRI, and SalI restriction endonucleases was quantitatively determined. The platinum complex inhibits the cleavage of plasmid pHC624 DNA linearized by BglI restrictase. From the p...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1992-12-01 00:00:00
abstract：:Analogs of carbonyl cyanide phenylhydrazone providing no reaction with nucleophilic groups and lacking acidobasic properties, respectively, were synthesized for study of mechanism of uncoupling effect on oxidative phosphorylation. Their retention, influence on proton transport, abilities to SH--groups modify and to st...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1988-10-01 00:00:00
abstract：:The hyperpolarisation of the membrane potential in Characeae above that of the diffusion potential is explained by the operation of the electrogenic proton pump. We studied the interaction of calcium with the functioning of the pump. The membrane potential was measured using the standard microelectrode technique. An i...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:The voltage dependent ionic currents in cultured embryonic skeletal myocytes at stages of development ranging from 1 to 6 day were studied using the whole-cell patch clamp technique. Sodium (INa) and calcium (ICa) inward and potassium (IK) outward currents were observed at all stages. INa did not differ from that desc...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1993-06-01 00:00:00
abstract：:Somatostatin analogues are currently used to treat various disorders such as hypersecretion and different neuroendocrine tumors. In this study we examined the effects on the adrenal cortex of somatostatin (SRIH-14) and octreotide administered subcutaneously twice daily for 5 days to adult male rats. Control rats recei...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2008-09-01 00:00:00
abstract：:A number of computational methods for the description of the ligand-receptor interaction that were developed in the past decade are reviewed in this paper. The central two sections introduce the methods that are already established as useful tools for the qualitative and quantitative description of ligand-receptor com...
journal_title：General physiology and biophysics
pub_type： 杂志文章,评审
doi：
更新日期：1999-09-01 00:00:00
abstract：:The passive mechanical properties of whole muscle in active and nonactive states are compared. The experimental results are presented as stress-strain curves, which are analyzed in the framework of the current theoretical background [viz. the freely-jointed chain model (FJCM) and the worm-like chain model (WLCM)] in a...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1999-06-01 00:00:00
abstract：:Low-conductance chloride channel from skeletal muscle SR vesicles of the crayfish Astacus fluviatilis was incorporated into planar lipid bilayers and its basic characteristics were investigated. The channel has a relatively low unitary conductance of 26 pS in symmetrical 160 mmol/l choline-chloride. The dependence of ...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1991-12-01 00:00:00
abstract：:Hyperglycemia impairs oxidative capacity in skeletal muscle. Muscle oxidative capacity is regulated by peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α). Transcutaneous carbon dioxide (CO2) enhances PGC-1α expression in skeletal muscle. Therefore, the aim of this study was to clarify the effects of...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2018048
更新日期：2019-05-01 00:00:00
abstract：:This study specified the role of several key calcium-operating ion channels in contraction/relaxation of human detrusor muscle as possible target for overactive bladder (OAB) treatment. Detrusor samples, obtained from 18 males (average age 61.5 ± 5.9 years), were investigated by organ tissue bath method with following...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2017064
更新日期：2018-07-01 00:00:00
abstract：:Electron spin resonance spectroscopy (ESR) was used to study the effects of amphiphilic amines of the carbamate, amide, and ester type and amine oxide on the photosynthetic system of spinach chloroplasts. The ESR signal II connected to the photosynthetic center PS II donor side was observed to diminish in the presence...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1990-12-01 00:00:00
abstract：:Pretreatment with diazoxide, mitochondrial K(ATP) channel opener, was found to protect the rat heart against ischemia/reperfusion injury. Our aim was also to characterize the effects of diazoxide on the alterations of regulatory myocardial proteins, on mitochondrial ultrastructure, integrity and induction of apoptotic...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2007-06-01 00:00:00
abstract：:Homocysteine (Hcys) may be implicated in different diseases, especially in cardiovascular illnesses. The most reactive form of Hcys is its cyclic thioester-homocysteine thiolactone (HTL), which is formed in plasma and represents up to 0.29% of plasma total Hcys. Recently, it has been observed that Hcys and HTL may mod...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2010_02_186
更新日期：2010-06-01 00:00:00
abstract：:The hydrolytic activity and interaction of acidic and neutral phospholipase A2 (PLA2) with large unilamellar liposomes treated with cobra venom cytotoxin Vc5 (CT Vc5) were studied to more fully understand the modulating effects of cationic membrane-active peptides on PLA2. Studies were done by fluorescence displacemen...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1995-04-01 00:00:00
abstract：:Thiamine deficiency (TD) results in lactate acidosis, which is associated with neurodegeneration. The aim of this study was to investigate this alteration in primary rat brain endothelia. Spectrophotometric analysis of culture media revealed that only a higher concentration of pyrithiamine, which accelerates the intra...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：2005-12-01 00:00:00
abstract：:Photon emissions were measured at ambient temperature (21°C) in complete darkness once per min from cultures of 10(6) cells during the 12 h following removal from 37°C. The energy of emission was about 10(-20) J/s/cell. Of 8 different cell lines, B16-BL6 (mouse melanoma cells) demonstrated the most conspicuous emissio...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：10.4149/gpb_2011_03_301
更新日期：2011-09-01 00:00:00
abstract：:The plasma membrane H(+)-ATPase of Neurospora has been reconstituted into planar lipid bilayer membranes by means of the vesicle-fusion technique described by Finkelstein and his collaborators (Zimmerberg et al., 1980; Cohen et al., 1980, 1984; Akabas et al., 1984). Enzyme was first transferred from isolated plasma me...
journal_title：General physiology and biophysics
pub_type： 杂志文章
doi：
更新日期：1993-10-01 00:00:00
