Abstract：
:The platelet activating factor (PAF) receptor of the guinea pig peritoneal eosinophil was characterized by radioligand ([3H]WEB 2086) binding and measurement of PAF-stimulated membrane GTPase activity. Specific binding of [3H]WEB 2086 was rapid, reversible and saturable, with an equilibrium KD of 20.4 nM at 0 degrees C, and was displaced competitively by unlabelled PAF with a KI of 3.26 nM and a pseudo-Hill coefficient significantly less than unity (0.44). The affinity of PAF for these binding sites was reduced by the nonhydrolysable GTP analogue 5'-guanylylimidodiphosphate (GppNHp), suggesting the coupling of PAF receptors to intracellular effectors through a guanine nucleotide-binding protein (G protein). PAF stimulated a membrane-associated GTPase, indicating the formation of a G protein alpha subunit-GTP complex upon agonist occupation of the PAF receptor. The EC50 for PAF stimulation was 25.5 nM and the Hill coefficient was significantly less than unity (0.56), while the response to 1 microM PAF was antagonised by WEB 2086 with an IC50 of 128 nM and a slope factor not significantly different from unity (0.91), suggesting the coupling of multiple classes of PAF receptors to the G protein. The activation of GTPase by PAF was insensitive to inhibition by cholera toxin; basal GTPase activity was increased by pertussis toxin and no further stimulation was attainable with PAF.
journal_name
Life Scijournal_title
Life sciencesauthors
Dent G,Barnes PJdoi
10.1016/0024-3205(93)90045-5subject
Has Abstractpub_date
1993-01-01 00:00:00pages
1633-40issue
20eissn
0024-3205issn
1879-0631pii
0024-3205(93)90045-5journal_volume
52pub_type
杂志文章相关文献
LIFE SCIENCES文献大全abstract：:Progressive lysis of bone in loose total hip replacement has been ascribed to the capacity of the synovial-like membrane present at the bone interface to produce prostaglandin E2 and cytokines such as tumor necrosis factor (TNF alpha). Phospholipase A2 (PLA2) produces rate limiting precursor i.e. arachidonic acid in t...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(96)00342-6
更新日期：1996-01-01 00:00:00
abstract：:Iron imbalance has been implicated in oxidative injury associated with many brain diseases. The present study investigated the importance of iron location in hydroxyl radical (.OH) generation and the link between .OH production evaluated by the salicylate method and lipid peroxidation monitored by thiobarbituric acid-...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(00)00638-x
更新日期：2000-06-16 00:00:00
abstract：:Administration of ovine-prolactin (O-PRL) stimulated Ca2+ uptake in isolated duodenal cells prepared from vitamin D-deficient rats. The time course of this effect was biphasic: uptake activity reached a peak in 2.5 hrs followed by a decrease at 5 hrs to original levels. This stimulatory effect of O-PRL was observed in...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(90)90568-c
更新日期：1990-01-01 00:00:00
abstract：AIMS:The present work evaluated the anti-inflammatory/antioxidant activity of a well characterized extract from Citrus bergamia Risso and Poiteau (CBE), containing neoeriocitrin, naringin, neohesperidin and other flavonoids, on human NCTC 2544 keratinocytes treated with interferon-gamma (IFN-γ) and histamine (H). MAIN...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2012.04.043
更新日期：2012-06-27 00:00:00
abstract：:beta-Adrenergic agonists used in therapy of premature labor and asthma cross the placenta and can affect development of the fetal nervous system. In the current study, pregnant rats were given 10 mg/kg of terbutaline on gestational days 17, 18 and 19 and adrenergic receptor binding capabilities examined in brain regio...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(90)90440-3
更新日期：1990-01-01 00:00:00
abstract：:Activated hepatic stellate cells (HSC; lipocytes; Ito cells) proliferate and are responsible for extracellular matrix synthesis during hepatic fibrogenesis. During activation, HSC undergo transdifferentiation into myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA). Adenosine 3', 5'-cyclic monophosphate (c...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(99)00157-5
更新日期：1999-01-01 00:00:00
abstract：OBJECTIVE:To investigate the expression and time-dependent manner of bradykinin (BK) as well as its receptors (Bradykinin receptors 1 and 2, B1R and B2R) in spinal cord ischemia-reperfusion injury (SCII) in rat model. METHODS:Sprague-Dawley (SD) rats were subjected to 1 h of infra-renal abdominal aorta occlusion and r...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2018.12.034
更新日期：2019-02-01 00:00:00
abstract：:We previously demonstrated that tissue-type plasminogen activator (t-PA) specifically bound to its receptor (t-PAR) on human umbilical vein endothelial cells (HUVEC). In addition to analyses of t-PA binding to plasminogen activator inhibitor-1 (PAI-1) in the extracellular matrix (ECM) and to the t-PAR, we further eval...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(00)80007-7
更新日期：2000-01-01 00:00:00
abstract：AIMS:We have developed biochemical and cell based assays to characterize small therapeutic molecules that inhibit the DNA damage checkpoint enzyme, Chk1 (Checkpoint kinase 1). MAIN METHODS:To prepare a screen of large chemical libraries, we purified the full-length and the catalytic domain versions of human Chk1. We c...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2011.06.010
更新日期：2011-08-15 00:00:00
abstract：:Gloriosaols A-C, isolated from Yucca gloriosa (Agavaceae), are novel phenolic compounds structurally related to resveratrol. In the present study, we show that gloriosaols possess antiproliferative and pro-apoptotic activity on tumor cells of different histogenetic origin and that their cell growth inhibition potentia...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2007.07.010
更新日期：2007-08-23 00:00:00
abstract：:To investigate whether endogenous opioid peptides mediate time-dependent changes in ventilatory control during prolonged hypoxia, we studied four adult goats at rest during 14 days at simulated high altitude in a hypobaric chamber (PB approximately 450 Torr). Arterial PCO2 fell during the first several hours of hypoxi...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(87)90260-8
更新日期：1987-02-16 00:00:00
abstract：:Both in men and rats, most of the ethanol ingested at a low dose is metabolized before it reaches the systemic circulation. Oxidation of ethanol (mainly in the stomach) accounts for the bulk of this effect. This "first pass" metabolism (FPM) may be viewed as a barrier which protects against the systemic toxicity of et...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(85)90470-9
更新日期：1985-08-12 00:00:00
abstract：:A time course study on the effects of an interferon inducing agent, polyriboinosinic polyribocytidylic acid (poly rIrC) on the hepatic cytochrome P-450 dependent progesterone metabolism was performed. Administration of a single dose of poly rIrC (10 mg/kg i.p.) to adult male Wistar rats caused a time dependent effect ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(93)90029-3
更新日期：1993-01-01 00:00:00
abstract：AIMS:Previous work has demonstrated that ketogenic diets promote white fat browning; however, the exact mechanisms underlying this phenomenom have yet to be elucidated. Recently, an in vitro study showed that supraphysiological concentrations of β-hydroxybutyrate (βHB) had a strong influence on the induction of adipocy...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2019.116683
更新日期：2019-09-01 00:00:00
abstract：:An increase in natural killer (NK) cell activity can be conditioned with a one trial learning paradigm to demonstrate the interaction between the central nervous system (CNS) and the immune system. In order to demonstrate learning possibilities during 'non-conscious' state, mice were anesthetized with a ketamin/rompun...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(92)90573-8
更新日期：1992-01-01 00:00:00
abstract：AIMS:The objective of this study was to establish a more accurate analytical model and method for grip strength test of mice and to investigate the beneficial effects of lifelong exercise training to prevent functional decline of muscle during aging. MAIN METHODS:Fifty randomly selected adult male BALB/c mice (24-56 w...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2020.117603
更新日期：2020-06-15 00:00:00
abstract：AIMS:Constant development of chemotherapeutic strategies has considerably improved the efficiency of tumor treatment. However, adverse effects of chemotherapeutics enforce premature treatment cessation, which leads to the tumor recurrence and accelerated death of oncologic patients. Recently, sodium ascorbate (ASC) has...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2019.116657
更新日期：2019-09-01 00:00:00
abstract：:Anandamide (arachidonylethanolamide), isolated from porcine brain, has been shown to bind to the cannabinoid receptor and also to produce cannabimimetic activity in pharmacological assays. This study examined structure-activity relationships in alkylated anandamide analogs. The analogs were evaluated for their ability...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(95)00187-b
更新日期：1995-01-01 00:00:00
abstract：:We investigated the effects of the chronic administration of hesperetin on the activation of the antioxidant defence system in mice in which oxidative stress had been induced by 7,12-dimethylbenz(a)anthracene (DMBA). Mice were divided randomly into three treatment groups. Hesperetin was administered orally to two of t...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2008.03.002
更新日期：2008-05-23 00:00:00
abstract：:T cell receptor (TCR/CD3) induced fluctuations in intracellular free ionizied calcium, [Ca2+]i, was analysed in the human T leukemia cell clone, Jurkat, cultured in the presence of the opioid methionine enkephalinamide (Met-Enk) in titrated concentrations (10[-7] to 10[-15] M) or saline (PBS). In the majority of indiv...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(98)00055-1
更新日期：1998-01-01 00:00:00
abstract：:Effects of lithium (Li) deficiency and/or immobilization stress on the thymus weight and differential blood count of rats were studied. The thymus weight of the rats fed a low Li diet were lighter than those of rats fed a Li supplemented diet, whether the rats were exposed to stress or not. Of the rats not exposed to ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(97)00740-6
更新日期：1997-01-01 00:00:00
abstract：AIMS:Transplantation of bone marrow mononuclear cells (BMMCs) exerts neuroprotection against cerebral ischemia. We examined the therapeutic timepoint of allogeneic BMMC transplantation in a rat model of focal cerebral ischemia, and determined the effects of repeated transplantation outside the therapeutic window. MAIN...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2013.12.016
更新日期：2014-01-24 00:00:00
abstract：:During the myocardial protection induced by ischemic preconditioning a reduction in myocardial metabolism occurs due to activation of the A1 adenosine receptors. This study investigates whether preconditioning changes both resting coronary flow and the magnitude of coronary reactive hyperemia and whether A1 adenosine ...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/s0024-3205(99)00034-x
更新日期：1999-01-01 00:00:00
abstract：:Propentofylline (PPF) is a xanthine derivative with pharmacological effects that are distinct from those of classic methylxanthines. It depresses the activation of microglial cells and astrocytes, which is associated with neuronal damage during neural inflammation and hypoxia. Our previous studies showed that PPF impr...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2016.02.028
更新日期：2016-03-01 00:00:00
abstract：AIMS:Colorectal cancer (CRC) is one of the most common cancers with poor prognosis worldwide. The advent of immunotherapy has greatly improved survival in refractory patients of CRC. In this study, we aimed to identify reliable immune classification and biomarkers that predict immunotherapeutic responses in CRC patient...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2020.118368
更新日期：2020-11-15 00:00:00
abstract：:Ten neuropeptides were measured by RIA in human cerebrospinal fluid obtained from 30 normal volunteers. The levels of seven peptides (corticotropin releasing factor, adrenocorticotropin, vasoactive intestinal peptide, somatostatin, beta-endorphin, beta-lipotropin, and the N-terminal fragment of proopiomelanocortin) we...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(85)90139-0
更新日期：1985-09-30 00:00:00
abstract：:In order to investigate the action of ethanol on the anterior pituitary gland, the effect of ethanol on prolactin secretion in vitro was studied. Ethanol significantly increased the in vitro incorporation of 3H-leucine into both prolactin contained within the pituitary gland and that released into the medium. The enha...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(84)90473-9
更新日期：1984-11-05 00:00:00
abstract：AIMS:Sickle cell disease (SCD) pathogenesis leads to recurrent vaso-occlusive and hemolytic processes, causing numerous clinical complications including renal damage. As vasoconstrictive mechanisms may be enhanced in SCD, due to endothelial dysfunction and vasoactive protein production, we aimed to determine whether th...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2014.08.021
更新日期：2014-11-04 00:00:00
abstract：:Down syndrome (DS) is the most common chromosomal abnormality and is associated with an extra copy of the chromosome 21. Although several markers are commonly used during pregnancy for the screening of DS, the definitive diagnosis is based on karyotype after amniocentesis, which is an expensive and laborious analysis....
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/j.lfs.2004.09.003
更新日期：2004-12-10 00:00:00
abstract：:Several serotonin (5-HT) receptor antagonists with varying specificities for the 5-HT receptor types, were studied with regard to their effects on blood glucose levels in mice. The non-selective antagonists, metergoline and methysergide, proved to be hyperglycemic at doses commonly used to antagonize 5-HT receptors. I...
journal_title：Life sciences
pub_type： 杂志文章
doi：10.1016/0024-3205(91)90023-5
更新日期：1991-01-01 00:00:00
