Abstract:
:Hemi-pituitary glands of ovariectomized rats were superfused for 4 h with either LHRH or the analog buserelin (HOE 766) at several concentrations, and thereafter with medium only for another 1.5 h. In a further experiment glands were exposed for 2.5 h to LHRH or buserelin at a single concentration (5 ng/ml) and subsequently for another 2.5 h to either the same agonist (LHRH or buserelin) alone (5 ng/ml), the agonist plus an LHRH-antagonist (ORG 30093, 1000 ng/ml), the LHRH- antagonist alone, or medium alone. LHRH and buserelin stimulated gonadotropin release equally well. After cessation of this stimulation, the gonadotropin release by the buserelin-treated pituitary glands and the glands, treated with the highest dose of LHRH (1000 ng/ml), continued, while the release by the glands, treated with the lower doses of LHRH, declined. The LHRH-antagonist completely blocked the release of LH, stimulated by buserelin or LHRH, as well as the prolonged activation of the release, caused by buserelin pre-treatment. In a superfusion experiment with pituitary cell aggregates of 14-day-old intact female rats, buserelin stimulated the release of LH much more effectively than LHRH itself. Moreover, the release caused by buserelin declined more slowly after cessation of the stimulation. Finally, in a pituitary cell monolayer culture the Kd's of LHRH, buserelin and the antagonist were determined as 4.7 X 10(-9) M, 2.4 X 10(-10) M and 4.6 X 10(-9) respectively. It was concluded that the estimates of the potencies of LHRH and buserelin depend on the choice of the test-system. It is suggested that the long duration of action of buserelin is at least partly due to prolonged binding to the LHRH-receptor.
journal_name
Life Scijournal_title
Life sciencesauthors
Koiter TR,Denef C,Andries M,Moes H,Schuiling GAdoi
10.1016/0024-3205(86)90524-2subject
Has Abstractpub_date
1986-08-04 00:00:00pages
443-52issue
5eissn
0024-3205issn
1879-0631pii
0024-3205(86)90524-2journal_volume
39pub_type
杂志文章相关文献
LIFE SCIENCES文献大全abstract::We studied the effects of cAMP on cytokine (interferon-gamma plus tumor necrosis factor-alpha)-induced stimulation of tetrahydrobiopterin (BH4) synthesis in human umbilical vein endothelial cells (HUVEC). The cytokine mixture caused a marked increase in the biosynthesis and release of BH4 by HUVEC. Dibutyryl-cAMP prod...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/s0024-3205(02)01503-5
更新日期:2002-03-22 00:00:00
abstract::The present study investigates the effect of a pituitary hormone (LH) and a thymic factor (Thymosin Fraction 5 = TF5) on in vitro and in vivo spleen cell proliferative response of 2, 6 and 8-month-old Balb/c mice. In vitro experiments showed that the addition of LH at various concentrations (0.5, 5, 50 or 500 ng/ml) t...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(90)90031-l
更新日期:1990-01-01 00:00:00
abstract::The dramatic activities of bradykinin and related peptides as mediators of pain, inflammation and hypotension have been intensely studied for several decades. More recently, the involvement of bradykinin in regulation of ion transport by epithelia, hormone release from endocrine organs, energy metabolism, tissue growt...
journal_title:Life sciences
pub_type: 杂志文章,评审
doi:10.1016/0024-3205(92)90201-y
更新日期:1992-01-01 00:00:00
abstract::5-Bromo-2'-deoxyuridine (BrdU) has been recently found to enhance adrenal glucocorticoid secretion in rats. Since BrdU-labeling is today the most employed technique for assessing cell proliferation, we have investigated whether this side-effect of BrdU may influence mitotic activity (as evaluated by metaphase-arrested...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/s0024-3205(97)00439-6
更新日期:1997-01-01 00:00:00
abstract::Rats were made sensitive to the effects of the opioid antagonist naltrexone by treating them once weekly with cumulative doses of the drug (1, 3, 10, 30 and 100 mg/kg). Sensitization was monitored by measuring salivation following naltrexone administration. During the first week of treatment, no salivation was noted f...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(92)90341-l
更新日期:1992-01-01 00:00:00
abstract::Tramadol is a clinically-effective, centrally-acting analgesic. This drug is a racemic mixture of two enantiomers, each one displaying different mechanisms: (+)tramadol displays opioid agonist properties and inhibits serotonin reuptake while (-)tramadol inhibit preferentially noradrenaline reuptake. The action of tram...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/s0024-3205(98)00369-5
更新日期:1998-01-01 00:00:00
abstract::As a decrease in cholinergic neurons has been observed in Alzheimer's Disease (AD), therapeutic approaches to AD include inhibition of acetylcholinesterase to increase acetylcholine levels. Evidence suggests that acetylcholine release in the CNS is modulated by negative feedback via presynaptic M2 receptors, blockade ...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/s0024-3205(98)00598-0
更新日期:1999-01-01 00:00:00
abstract::Preconditioning (PC) is a potential approach to myocardial protection. We hypothesize that brief ischemia or adenosine given prior to an extended period of warm ischemia may prevent myocardial stunning by altering myocardial metabolism. Using a global ischemia model, 19 dogs were subjected to no PC(control), two episo...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2007.08.037
更新日期:2007-10-13 00:00:00
abstract:AIMS:Multiple sclerosis (MS) whose pathogenesis is still unclear is a chronic progressive disease in the central nervous system. Gut microbiota can directly or indirectly affect the immune system through the brain gut axis to engage in the occurrence and development of the disease. MATERIALS AND METHODS:C57BL/6 mice w...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2020.117747
更新日期:2020-07-15 00:00:00
abstract::Based on the finding of decreased mitochondrial complex I activity in the substantia nigra of patients with Parkinson's disease, we propose that the consequent reduction of ATP synthesis and increased generation of reactive oxygen species may be a possible cause of nigrostriatal cell death. Since sulfhydryl groups are...
journal_title:Life sciences
pub_type: 杂志文章,评审
doi:10.1016/s0024-3205(98)00472-x
更新日期:1999-01-01 00:00:00
abstract::In the present study we compared, in vivo in rats, the hepatobiliary transport of monovalent (silver:Ag) and divalent metals (zinc:Zn; cadmium:Cd) with that of copper (Cu). Cu can have two oxidation states in vivo, i.e. Cu(I) and Cu(II). Studies were performed in normal Wistar (NW) rats and mutant GY Wistar rats. The ...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(96)00447-x
更新日期:1996-01-01 00:00:00
abstract:AIMS:This study was performed to assess isolated and combined effects of nandrolone and resistance training on the blood pressure, cardiac electrophysiology, and expression of the β1- and β2-adrenergic receptors in the heart of rats. MAIN METHODS:Wistar rats were randomly divided into four groups and submitted to a 6-...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2013.04.002
更新日期:2013-05-30 00:00:00
abstract:AIMS:Benzodiazepines (BZDs) produce various pharmacological actions by binding to and allosterically regulating GABAA receptors. Several in vitro studies have demonstrated diazepam, the prototypic BZD, produces a high-dose action that cannot be countered with the classical BZD-binding site antagonist flumazenil. Here, ...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2019.117033
更新日期:2019-12-15 00:00:00
abstract::Recent evidence suggests that the Type 1 opiate receptor (in rat striatal patches) is a mobile receptor which is able to adopt a mu, delta, or kappa opiate receptor ligand selectivity pattern under appropriate conditions. In this paper, we have investigated such a possibility for Type 2 opiate receptors which are visu...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(82)90183-7
更新日期:1982-10-18 00:00:00
abstract::The anticonvulsant activity of U-54494A was studied in a 4-aminopyridine (4-AP) epilepsy model using extracellular recordings in in vitro hippocampal slices. Field potentials were evoked by stimulation of Schaffer collaterals, and recorded from the CA1 region of the hippocampus after infusion of 4-AP in the absence an...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(92)90381-x
更新日期:1992-01-01 00:00:00
abstract::The study was designed to investigate the role of molybdenum iron-sulfur flavin hydroxylases in the pathogenesis of liver injuries induced by structurally and mechanistically diverse hepatotoxicants. While carbon tetrachloride (CCl4), thioacetamide (TAA) and chloroform (CHCl3) inflict liver damage by producing free ra...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2008.01.011
更新日期:2008-03-26 00:00:00
abstract::The lymphatic vessels have been implicated in maintenance of interstitial fluid homeostasis and immune responses, and pathological conditions including inflammation, wound healing, lymphedema and tumor progression. The knowledge about the lymphatic structure and function in muscles, especially in muscular disorders, r...
journal_title:Life sciences
pub_type: 杂志文章,评审
doi:10.1016/j.lfs.2018.09.043
更新日期:2018-10-15 00:00:00
abstract::Previous investigations showed that chronic metabolic acidosis (CMA) increased the paracellular permeability of ion and neutral hydrophilic molecules in the duodenum of rats and small intestinal-like cell lines. Since proteins of the claudin family have been known to regulate the paracellular transport in several epit...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2007.01.063
更新日期:2007-04-17 00:00:00
abstract::An experimental model which resembles human drug addiction was developed to study the effect of chronic drug (cocaine or morphine) administration on the immune system. As malnutrition has been associated with drug use, a low protein diet has been evaluated for its contribution to the impairment of the immune system du...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(91)90138-2
更新日期:1991-01-01 00:00:00
abstract::The risk of atherosclerosis (AS) ascends among post-menopausal women, while current hormone replacement therapy exerts several adverse effects. Alisol B 23-acetate (AB23A), a tetracyclic triterpenoid isolated from the rhizome of Alisma orientale, was reported to show multiple physiological activities, including regula...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2020.118030
更新日期:2020-10-01 00:00:00
abstract::The metabolism of benzene and toluene was investigated in preparations of human bone marrow incubated with S-adenosyl-L-methionine. Benzene undergoes a methyl-substitution reaction to yield toluene as a metabolite. Furthermore, toluene undergoes methyl-substitution in preparations of human bone marrow incubated with S...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(91)90100-p
更新日期:1991-01-01 00:00:00
abstract::The actions of insulin-like growth factor I (IGF-I) and growth hormone (GH) on lipid metabolism have been investigated in hormonally intact rats. The subcutaneous injection of IGF-I (100 micrograms) and GH (100 micrograms) lowered total cholesterol plasma levels. The in vitro assays on isolated rat adipocytes showed a...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(95)02067-s
更新日期:1995-01-01 00:00:00
abstract::Using absorption spectroscopy we have found that metallothionein I at concentrations as low as 1 microM reduces ferricytochrome c. This reduction is more potent than that of another abundant intracellular thiol, glutathione. Also, oxidation of ferricytochrome c which had been reduced by metallothionein I occurs more s...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(93)90019-y
更新日期:1993-01-01 00:00:00
abstract::In transversely sectioned rat hippocampal slices, population spikes and population "EPSPs" were recorded from CA1 neurones in response to the stimulation of Schaffer collateral and commissural inputs. High frequency tetanic stimulation (400 Hz, 200 pulses) of an input induced LLP of the homosynaptic response without s...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(84)90021-3
更新日期:1984-03-12 00:00:00
abstract::The effects of different kinds of acute stress on collagen-induced whole blood platelet aggregation and fibrinolysis in relation to blood serotonergic measures were studied. In rats water-immersion restraint stress resulted in a shortening of euglobulin clot lysis time (ECLT), an increase in tissue plasminogen activat...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(94)00855-8
更新日期:1994-01-01 00:00:00
abstract::Human histiocytic lymphoma cells (U-937) undergo similar differentiation when incubated with the phorbol ester 12-0-tetradecanoyl phorbol-13-acetate (TPA) and 1,25-dihydroxycholecalciferol. In this action, TPA somehow implicates calcium-sensitive and phospholipid-dependent protein kinase (protein kinase C), which is r...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(87)90105-6
更新日期:1987-05-25 00:00:00
abstract::Kinetics of activation of the NADPH oxidase in a fully soluble cell-free system from phorbol myristate acetate (PMA)-stimulated human neutrophils were investigated. In a cell-free system in which Mg2+ and sodium dodecyl sulfate, an anionic detergent required for the activation of NADPH oxidase are contained, cytosol p...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(90)90447-y
更新日期:1990-01-01 00:00:00
abstract::Optically active hydroperoxides of phospholipids including phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidic acid were synthesized, and their cytotoxicity to cultured bovine pulmonary artery endothelial cells was examined. Phospholipid hydroperoxides were readily incorporated into c...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/0024-3205(94)00684-9
更新日期:1994-01-01 00:00:00
abstract::Stem cells have potential to develop into numerous cell types, thus they are good cell source for tissue engineering. As an external physical signal, material stiffness is capable of regulating stem cell fate. Biomaterial stiffness is an important parameter in tissue engineering. We summarize main measurements of mate...
journal_title:Life sciences
pub_type: 杂志文章,评审
doi:10.1016/j.lfs.2017.04.014
更新日期:2017-06-01 00:00:00
abstract:AIMS:With the improvement of the survival rates in children acute lymphoblastic leukemia (ALL), some children ALL survivors show impaired cognitive function. Methotrexate (MTX), an essential component in ALL treatment, has been reported to be related to neurologic sequelae and to increased oxidative stress through its ...
journal_title:Life sciences
pub_type: 杂志文章
doi:10.1016/j.lfs.2019.116931
更新日期:2020-02-01 00:00:00