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Results 451 - 500 of 1568
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Zeng L - - 1996
Cell surface expression of multiple structurally and functionally distinct prostaglandin E2 (PGE2) receptors (Rs), designated the EP1, EP2, EP3, and EP4 Rs, is a principal determinant of the diverse cellular effects of PGE2. The RNK-16 line of rat large granular lymphocytes, which has served as a model for natural killer ...
Lemmens R - - 1996
1. Using the incorporation of [methyl-3H]thymidine as a proliferation marker, the effects of various nucleosides and nucleotides on endothelial LLC-MK2 cells were studied. We found that ATP, ADP, AMP and adenosine in concentrations of 10 microM or higher stimulate the proliferation of these cells. 2. Inhibition of ecto-ATPase (EC 3.6.1.15), ...
Mikuni-Takagaki Y - - 1996
To explore lineage-dependent responses to mechanical stress in bone cells, newborn rat calvarial cells, exhibiting differential characteristics of osteoblastic and osteocytic cells, were compared in their immediate and late responses to stretching. Seven fractions of sequentially prepared cells were cultured on Matrigel to promote their differentiation. By cyclically stretching the ...
Okuda H - - 1996
Norepinephrine stimulated lipolysis in rat fat cells while (-)-alprenolol completely inhibited this lipolysis. (-)-Alprenolol competed for (-)-[3H] dihydroalprenolol (DHA) binding sites on rat fat cells. The specific (-)-[3H]DHA binding sites identified by competition with (-)-alprenolol were found to be transferred to the solubilized supernatant during preparation of endogenous lipid droplets ...
May L G - - 1996
Techniques for the isolation of a highly pure population of viable osteoclasts are limited. For this reason, we developed an isolation procedure that results in a high yield of osteoclast-like cells, up to 92% pure, from 3-wk-old chicken tibias. The unique feature of the method is the migration of cells ...
Belhassen L - - 1996
Cardiac myocytes express the nitric oxide synthase isoform originally identified in constitutive nitric oxide synthase cells (NOS3), which mediates the attenuation by muscarinic cholinergic agonists of beta-adrenergic stimulation of L-type calcium current and contractility in these cells. However, calcium current and contractility in these cells. However, the reciprocal regulation of ...
Estival A - - 1996
Basic fibroblast growth factor (FGF-2) is synthesized as different molecular mass isoforms all lacking the signal-peptide sequence. The high molecular-mass isoforms (21-24 kDa) possess a signal sequence directing their nuclear translocation. The role of each isoform is still poorly understood, however, modifications in intracellular signalling pathways could explain some effects ...
Wang D - - 1996
The effects of adenosine on action potentials, rate-dependent activation failure (the cellular basis for second-degree atrioventricular [AV] block), and the recovery of excitability in rabbit isolated single AV nodal cells were studied using the whole-cell patch-clamp technique. Adenosine (1 micromol/L) shortened the duration, depressed the amplitude, and reduced the rate ...
Ockenfels H M - - 1996
The influence of the immunosuppressants, cyclosporin A (CsA) and FK506, on cAMP formation was studied in T cells from healthy controls and patients with psoriasis. While basal cAMP levels were not affected, CsA (1 microM) and FK506 (2 nM) prevented the isoprenaline (0.1 microM)-induced increase in cAMP formation. Half-maximal inhibition ...
Furger C - - 1996
Granulosa cells are known to be the site of action of various hormones and agents that regulate ovarian function. This study was conducted to evaluate the effects of gonadotrophins, vasoactive intestinal peptide (VIP), prostaglandin (PG) F2 alpha and angiotensin II on the cyclic AMP (c-AMP) signalling transduction pathway in human ...
Millul V - - 1996
Egression of atrial natriuretic peptide (ANP)-stimulated guanosine 3', 5'-cyclic monophosphate (cGMP) was compared with that of isoproterenol-stimulated adenosine 3', 5'-cyclic monophosphate (cAMP) in a rabbit collecting duct cell line transformed with a temperature-sensitive strain of simian virus 40 (SV40). At 39.5 degrees C (inactivated large T), cells exhibit major features ...
Nakamura J - - 1996
Adenylyl cyclase activity was determined in membranes from wild-type S49 murine lymphoma cells that had been exposed to ethanol for 4 hr. Mn-, NaF-, and forskolin-stimulated adenylyl cyclase activities of cells-pretreated with cycloheximide, puromycin, or serum deprivation-were significantly decreased by treatment with 50 mM of ethanol. As demonstrated for Mn-stimulated ...
Chang J Y - - 1996
Cultured cerebellar granule cells undergo programmed cell death when they are deprived of depolarizing KCl. Results from this study indicate that the cAMP analog cyclic 8-(4-chlorophenylthio) adenosine-3'5'-monophosphate (CPT-cAMP) can prevent the cell death in a dose-dependent manner, with the maximal effect seen at 500 microM. Approximately 70% of cells can ...
Guh J H - - 1996
The antiproliferative effect of osthole on rat vascular smooth muscle cells was examined in this study. A number of mitogenic agents, e.g., foetal-calf serum (10%, v/v) and platelet-derived growth factor (20 ng/ml), and pharmacological agents, e.g., serotonin (10 microM), ionomycin (3 nM), phorbol 12,13-dibutyrate (20 nM) and phorbol myristate acetate ...
Stanislaus D - - 1996
GH3 cells are a PRL-secreting adenoma cell line derived from pituitary lactotropes. These cells have been stably transfected with rat GnRH receptor complementary DNA to produce four cell lines: GGH(3)1', GGH(3)2', GGH(3)6', and GGH(3)12'. In response to either GnRH or Buserelin (a metabolically stable GnRH agonist), these cell lines synthesize ...
Jilling T - - 1996
Epithelial cells of the colonic crypt engage in cAMP-mediated fluid and electrolyte secretion. In addition to participating in electrolyte transport, colonic crypt cells also synthesize and secrete a number of proteins and peptides that play a crucial role in mucosal homeostasis. In the present study we show that cAMP regulates ...
Kumar R - - 1996
Adenosine is one of the most important inhibitory modulators of heart function, producing negative inotropic, chronotropic and dromotropic effects and is also a major regulator of coronary circulation. The decrease in contractility by adenosine is mediated through inhibition of adenylyl cyclase by Gi-proteins coupled to adenosine receptors. However, little is ...
Hausman G J - - 1996
Fetal hypophysectomy (hypox) slightly enhances lipid accretion in adipose tissue and markedly increases fat cell size and de novo lipogenesis. Thyroxine (T4) treatment (14 to 20 d) had no influence on fat cell size but markedly increased lipogenesis, lipid accretion, and apparent fat cell number in hypox fetuses. Although vascular ...
Staub M - - 1996
As has been shown earlier by us, the metabolism of extracellular deoxycytidine (dCyd) is 2-3 times higher in follicular and in PNA+ cells than in other cells. Deoxycytidine kinase (dCK) is one of the most important target enzymes for anti-proliferative drugs such as arabinosile-cytosine (ara-C), 2-Cl-deoxyadenosine (CdA). Neither the dCK ...
Hahn K - - 1996
Normal G(0) pig lymphocytes were maintained in a hypoxic or aerobic environment for one hour and then concurrently exposed to bleomycin at varying concentrations for a second hour. The cytochalasin-block micronucleus assay was used to determine cytotoxicity. Exposure to transient hypoxia significantly decreased the frequency of bleomycin-induced micronuclei per cell ...
Rao L G - - 1996
We previously developed two models of human osteoblasts with distinct differentiation stages using cells derived from iliac crest trabecular bone explants cultured long term in the presence (HOB + DEX) and absence (HOB - DEX) of 10 nM dexamethasone (DEX) (Wong et al., J Bone Miner Res 1990;5:803). Using these ...
Thoreux K - - 1996
Trophic effects of milk fermented with Lactobacillus helveticus, Lactobacillus paracasei ssp. paracasei, Bifidobacterium sp., or the combination of Lactobacillus bulgaricus and Streptococcus thermophilus (yogurt) were studied on the IEC-6 intestinal epithelial cell line. Incorporation of [methyl-3H]thymidine, mitochondrial dehydrogenase activities, cyclic AMP production, and differentiation of levels of the IEC-6 strain ...
Portillo M P - - 1995
The presence of beta1- and beta2-adrenoceptors has been clearly established in human fat cells. There is some controversy about the presence and function of beta3-adrenoceptors. It is well established that there are marked regional variations in catecholamine-induced lipolysis. In this work the possibility that a beta3-adrenoceptor plays a significant role ...
Bani D - - 1995
Recently, we demonstrated that relaxin (RLX), a peptide hormone of ovarian origin, inhibits growth and promotes differentiation of MCF-7 breast adenocarcinoma cells. We also showed that RLX stimulates the production of nitric oxide (NO) in several cell types. NO has been reported to have antitumor activity by inhibiting proliferation, promoting ...
Amikam D - - 1995
1. The effect of the novel, naturally occurring nucleotide 3'-5' cyclic diguanylic acid (c-di-GMP) on the lymphoblastoid Molt 4 cell line was studied. When exposed to this guanine nucleotide. Molt 4 cells exhibited a marked increase in [3H]thymidine incorporation, up to 200-fold at 50 microM c-di-GMP. Correspondingly, the DNA content ...
Kitten A M - - 1995
Osteogenic protein-1 (OP-1) stimulates bone morphogenesis in vivo and modulates osteoblast growth and differentiation in vitro. Treatment of ROS 17/2.8 cells with OP-1 resulted in a time- and concentration-dependent inhibition of [3H]thymidine incorporation. In contrast, OP-1 treatment stimulated phenotypic differentiation in ROS 17/2.8 cells, as indicated by enhanced 1) alkaline ...
Boyer J L - - 1995
1. Analogues of adenine nucleotides inhibited beta-adrenoceptor-stimulated cyclic AMP accumulation in C6 rat glioma cells with a pharmacological selectivity consistent with that for involvement of a P2Y-purinoceptor. 2. The inhibitory effect of adenine nucleotides was completely prevented by pretreatment of cells with pertussis toxin. 3. The capacity of a series ...
Omatsu-Kanbe M - - 1995
The presence and regulation of a hormone-sensitive cyclic GMP-inhibited cyclic nucleotide phosphodiesterase (cGI PDE) in rat brown adipose cells was investigated. cDNA clones for two cGI PDE isoforms, cGIP1 and cGIP2, have been isolated. Using a rat cGIP1 (RcGIP1) cDNA probe, RcGIP1 mRNA (approximately 5.3 kb) was detected in Northern ...
Nemoz G - - 1995
The expression of a constitutively activated Gs alpha protein in the rat thyroid cell line FRTL-5 causes an increase in the hormone-independent adenylyl cyclase activity and promotes TSH-independent growth of the cells. In spite of the constitutive activation of the adenylyl cyclase, the basal cAMP levels in these cells are ...
Tanaka H - - 1995
1 The ability of various prostaglandins (PGs) to inhibit monocyte chemotaxis induced by monocyte chemoattractant protein-1 (MCP-1) was investigated with a human monocytic leukaemia cell line, THP-1. Moreover, to investigate the mechanism of the inhibitory action of PGs the involvement of either intracellular adenosine 3': 5'-cyclic monosphosphate (cyclic AMP) accumulation ...
Yousefian J - - 1995
An apparatus was developed to apply positive or negative hydrostatic pressure dynamically to periodontal ligament (PDL) cells in vitro. The objective of this investigation was to construct this apparatus and to determine its effects on PDL cells. Human PDL cells were collected from freshly extracted premolars. At the sixth passage, ...
Splawski Judy B. - - 1995
Prostaglandin E(2) (PGE(2)) and other cAMP elevating agents inhibited neonatal but not adult T cell dependent Ig production. PGE(2) did not inhibit IL-2-dependent anti-CD3 stimulated neonatal T cell proliferation or T cell-dependent neonatal B cell proliferation. The results could not be explained by differences in the effect of PGE(2) on ...
Orbo A - - 1995
The ratio between extracellular levels of cGMP and cAMP (cGMPex/cAMPex) has been proposed as diagnostic tool in many forms of malignancies. In vitro and in vivo studies have shown that sex steroids effect extracellular levels of cyclic nucleotides. Cyclic changes of these hormones in premenopausal women may disturb the interpretation ...
Smerdely P - - 1995
Previously, we have shown that the iodide was able to inhibit TSH induced thyrocyte proliferation by arresting the cell cycle at G0G1 and G2M, suggesting that the iodide may be exerting its effects through more than the TSH-adenylate cyclase-cAMP system. To confirm the effects of iodide on the adenylate cyclase ...
Toki S - - 1995
PS-990, which is a novel microbial metabolite, induced neurite formation in a murine neuroblastoma cell line, Neuro2A. In the presence of PS-990 at 30 micrograms/ml, significant neurite outgrowth was observed. Cultures maintained for 12 h in the presence of PS-990 resulted in the maximal number of neurite-bearing cells, and then ...
Sorci G - - 1995
We studied the activity and the ultracytochemical localization of membrane-bound guanylate cyclase (GC) after stimulation with rat atrial natriuretic peptide (rANP), porcine brain natriuretic peptide (pBNP), rat brain natriuretic peptide (rBNP), or porcine C-type natriuretic peptide (CNP) in rat C6 glioma cells during proliferation or following exposure of confluent cells ...
Vittet D - - 1995
Intracellular signaling processes by which hematopoietic growth factors regulate megakaryocytopoiesis remain incompletely understood. Cyclic AMP (cAMP) has been shown to be implicated in the regulation of growth and differentiation in various normal and malignant cell types. Since a few studies have suggested the possible involvement of the cAMP pathway as ...
Nohutcu R M - - 1995
Periodontal ligament cells (PDL) are thought to play a major role in promoting periodontal regeneration. Recent studies, focused on characterizing PDL cells, have been directed at establishing their osteoblast-like properties and determining biological mediators and/or factors that induce osteoblastic cell populations in the PDL. The glucocorticoid, dexamethasone (Dex), has been ...
Gonzales J M - - 1995
Cyclic AMP (cAMP) regulates many important physiological processes. Barbiturates influence cAMP regulation, possibly through effects on G proteins. This study used intact S49 mouse lymphoma cells to characterize the role of G proteins in the effect of barbiturates on cAMP regulation. cAMP accumulation was determined in intact S49 WT (wild-type) ...
Agarwal R P - - 1995
Salvage and de novo purine and pyrimidine nucleotide syntheses were studied in H9 (a human lymphoid cell line) and H9-AZT cells (chronically zidovudine-exposed H9 cells). H9-AZT cells incorporated 18% and 27% more hypoxanthine and uridine, respectively, than H9 cells. The incorporation of the formate and bicarbonate was similar in both ...
Hoermann R - - 1995
The role of hCG as a stimulator of the human thyroid has been a subject of controversy, because discrepant results have been obtained in different in vitro assays. In an attempt to explain the variation observed in the thyroid response to hCG, we investigated the ability of hCG and that ...
Huang R - - 1995
We have previously described a novel human B cell differentiation factor (BCDF), 446-BCDF, that is distinct biochemically and functionally from other cytokines. Since signal transduction pathways involved in human B cell differentiation have been incompletely studied and are poorly understood, we assessed the effects of 446-BCDF on various intracellular second ...
Yamaguchi M - - 1995
To determine whether cAMP regulates mouse placental lactogen-I (mPL-I) and mPL-II secretion at midpregnancy in vitro, mouse placental tissue from day 9 of pregnancy was dispersed with collagenase, cells were fractionated on a Percoll gradient, and the purified trophoblast cells were plated in a serum-free medium. The cells were then ...
Patel M J - - 1995
LLC-PK1 epithelial cells and RFL-6 fibroblasts secreted both cyclic AMP (cAMP) and cyclic GMP (cGMP) when costimulated with forskolin and 3-morpholinosydnonimine (a chemical nitric oxide generator). Intracellular cAMP levels as high as 1100 and 12,000 pmol/10(6) cells were achieved for the two cell types, respectively. These levels were high enough ...
Albert D A - - 1995
Myc is implicated in the control of growth in a variety of cell types. I investigated c-myc gene expression in several lymphoid cell lines to determine the response to cyclic AMP. Cyclic AMP causes a precipitous decline in c-myc message concentration that precedes G1 cell cycle arrest in wild type ...
Qin Y - - 1995
The effect of somatostatin analog RC-160 on the growth of CFPAC-1 human pancreatic cancer cells in vitro was investigated. RC-160 effectively inhibited the proliferation of CFPAC-1 cells in culture, inducing a time- and dose-dependent decrease in the number of treated cells. A significant suppression of cell growth was observed after ...
McDermott A M - - 1995
In some cells a supersensitive adenylyl cyclase response follows hormonal inhibition of the enzyme. We have compared the effect of pre-treatment with noradrenaline in RINm5F cells to that in cells known to demonstrate supersensitivity. In NG108-15 cells, 12 or 24 hours pre-treatment with 1-10 microM noradrenaline markedly enhanced forskolin (1 ...
Ohrui T - - 1995
This paper describes a method for measuring the increase in halide permeability of isolated airway epithelial cells induced by adenosine 3',5'-cyclic monophosphate (cAMP). Suspensions of isolated cells, known to contain the cystic fibrosis transmembrane conductance regulator (CFTR), were placed in the upper part of a Swinnex filter holder containing a ...
Funatsumaru S - - 1995
A primary culture of undigested fat tissue fragments was used to obtain fat cells in vitro. On day 2 of culture, immature fat cells, which are fibroblast-like fat cells containing fine lipid droplets, appeared, surrounding the fat tissue fragments, and began to proliferate extensively. Afterwards, these fibroblast-like fat cells grew ...
Deguine V - - 1995
It has been proposed that cyclic adenosine monophosphate (cAMP) is involved in the differentiation of several cell types and this study analysed whether von Willebrand factor (vWf) synthesis, which is a marker of the megakaryocyte maturation of these cells, would be enhanced by agents acting on cAMP formation. Different compounds ...
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