scholarly journals Regulation of β-adrenoceptor density and mRNA levels in the rat heart cell-line H9c2

1996 ◽  
Vol 317 (3) ◽  
pp. 925-931 ◽  
Author(s):  
Volker DANGEL ◽  
Jeanette GIRAY ◽  
Dieter RATGE ◽  
Hermann WISSER
Keyword(s):  
Cell Line ◽  
Half Life ◽  
Rat Heart ◽  
Radioligand Binding ◽  
Mrna Level ◽  
Fold Increase ◽  
Heart Cell ◽  
H9c2 Cell ◽  
Heart Cells ◽  
Mrna Levels

The regulation of the expression of β-adrenoceptors (β-ARs) is not thoroughly understood. We demonstrate that the rat heart cell-line H9c2 expresses both β1- and β2-ARs. In radioligand-binding experiments, the maximal binding capacity of (-)-[125I]-iodocyanopindolol was determined as 18±0.6 fmol/mg of protein with a KD of 35.4±4.1 pM. Competitive radioligand-binding experiments with subtype-specific β-antagonists reveal a subtype ratio of β1- to β2-ARs of 29%:71%. With competitive reverse-transcriptase PCR we found β2-mRNA to be up to 1600 times more frequent than β1-mRNA. Treatment of the H9c2 cell-line with the β-adrenergic agonist (-)-isoproterenol (10-6 M), the antagonist (-)-propranolol (10-6 M) and the glucocorticoid dexamethasone (500 nM) induces regulatory effects on both the β-AR protein and mRNA level. Isoproterenol treatment leads to down-regulation of the total receptor number by 56±4%, due to a decrease in β2-ARs, while maintaining the β1-AR number constant. On the transcription level, both β1-and β2-mRNAs are decreased by 30% and 42% respectively. mRNA stability measurements reveal a reduced half-life of β2-mRNA from 9.3 h to 6.5 h after isoproterenol treatment. Incubation of cells with (-)-propranolol does not affect the amounts of β-ARs and their mRNAs. Dexamethasone induces a 1.8±0.2-fold increase in β-AR number over the basal level as well as a 1.9±0.2-fold increase in the amount of β2-mRNA. Because the half-life of β2-mRNA was unaffected by dexamethasone, the increased β2-mRNA level must be due to an enhanced transcription rate. The β1-mRNA levels are unchanged during dexamethasone-incubation of the cells. Our data clearly demonstrate that treatment of H9c2 rat heart cells with isoproterenol and dexamethasone induces alterations in the level of RNA stability as well as gene transcription, leading to altered receptor numbers.

HIF1A is Overexpressed in Medulloblastoma and its Inhibition Reduces Proliferation and Increases EPAS1 and ATG16L1 Methylation

2018 ◽  
Vol 18 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Gustavo Alencastro Veiga Cruzeiro ◽  
Maristella Bergamo dos Reis ◽  
Vanessa Silva Silveira ◽  
Regia Caroline Peixoto Lira ◽  
Carlos Gilberto Carlotti Jr ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Line ◽  
Cellular Proliferation ◽  
Mrna Level ◽  
Relevant Information ◽  
Protein Stabilization ◽  
Mrna Levels ◽  
Medulloblastoma Cell Line ◽  
Pediatric Medulloblastoma ◽  
Fresh Frozen

Background: Genetic and epigenetic modifications are closely related to tumor initiation and progression and can provide guidance for understanding tumor functioning, potentially leading to the discovery of new therapies. Studies have associated hypoxia-related genes to tumor progression and chemo/radioresistance in brain tumors. Information on the expression profile of hypoxiarelated genes in pediatric medulloblastoma, although scarce, may reveal relevant information that could support treatment decisions. Objective: Our study focused on evaluation the of CA9, CA12, HIF1A, EPAS1, SCL2A1 and VEGF genes in 41 pediatric fresh-frozen medulloblastoma sample. Additionally, we analyzed the effect of hypoxia and normoxia in the pediatric medulloblastoma cell-line UW402. Furthermore, we assessed the effects of HIF1A knockdown in cell-proliferation and methylation levels of genes related to hypoxia, apoptosis and autophagy. Method: qPCR was performed to evaluate mRNA levels, and Western blot to confirm HIF1A silencing in both patient samples and cell line. Pyrosequencing was performed to asses the methylation levels after HIF1A knockdown in the UW402 cell line. Results: A higher HIF1A mRNA level was observed in MB patients when compared to the cerebellum (non-tumor match). In UW402 MB cell-line, chemically induced hypoxic resulted in an increase of mRNA levels of HIF1A, VEGF, SCL2A1 and CA9 genes. Additionally, HIF1A knockdown induced a decrease in the expression of hypoxia related genes and a decrease of 30% in cell proliferation was also observed. Also, a significant increase in the methylation of ATG16L1 promoter and decrease in the methylation of EPAS1 promoter were observed after HIF1A knockdown. Conclusion: HIF1A knockdown in medulloblastoma cells lead to decreased cellular proliferation, suggesting that HIF1A can be a potential therapeutic target to be explored in the medulloblastoma. However, the mechanisms behind HIF1A protein stabilization and function are very complex and more data need to be generated to potentially use HIF1A as a therapeutical target.

Effect of Soil Salinity on the Expression of Betaine Aldehyde Dehydrogenase in Leaves: Investigation of Hydraulic, Ionic and Biochemical Signals.

1992 ◽  
Vol 19 (5) ◽  
pp. 555 ◽  
Author(s):  
KF Mccue ◽  
AD Hanson
Keyword(s):  
Enzyme Activity ◽  
Aldehyde Dehydrogenase ◽  
Half Life ◽  
Mrna Level ◽  
State Level ◽  
Betaine Aldehyde Dehydrogenase ◽  
Mrna Levels ◽  
Betaine Aldehyde ◽  
Hydraulic Signal ◽  
Leaf Disks

Betaine aldehyde dehydrogenase (BADH) catalyses the last step in glycine betaine synthesis. The levels of BADH enzyme and BADH mRNA have previously been shown to be increased several-fold by salt stress. To characterise this induction more thoroughly, BADH mRNA levels and enzyme activities were analysed in leaves of sugar beet plants (Beta vulgaris L.) subjected to different salinisation regimes. Following a salt shock (transfer from 0 to 400 mM NaCI) BADH enzyme activity rose slowly for several days. In contrast, BADH mRNA level first decreased for several hours, and then increased. When salt was leached from the rooting medium of salinised plants, BADH enzyme activity declined, with a half-life of more than 4 days. However, the level of BADH mRNA declined sharply with an apparent half-life of 2 h showing that transcription of the BADH gene or the stability of BADH mRNA in leaves can respond very dynamically to salinity changes around the root. In plants which had been gradually salinised and then held at various NaCl concentrations, the steady state level of enzyme rose continuously between 0 and 500 mM NaCl, whereas that of BADH mRNA reached a plateau at 100 mM NaCl. In general, the observed BADH mRNA fluctuations could not be satisfactorily explained by assuming them to be responses to hydraulic signals. This suggests the participation of a non-hydraulic signal or signals coming from the root. The non-hydraulic signal is unlikely to be NaCl, because leaf disks exposed to salt concentrations typical of the apoplast of salinised leaves did not accumulate BADH mRNA. A biochemical messenger is thus implied. Although abscisic acid application to leaf disks elicited significant increases in BADH mRNA level, these were several-fold smaller than those observed in leaves of intact salinised plants, suggesting the involvement of some other substance.

scholarly journals MicroRNA-130a–mediated down-regulation of Smad4 contributes to reduced sensitivity to TGF-β1 stimulation in granulocytic precursors

Blood ◽  
2011 ◽  
Vol 118 (25) ◽  
pp. 6649-6659 ◽  
Author(s):  
Mattias Häger ◽  
Corinna Cavan Pedersen ◽  
Maria Torp Larsen ◽  
Mette Klarskov Andersen ◽  
Christoffer Hother ◽  
...  
Keyword(s):  
Cell Growth ◽  
Growth Inhibition ◽  
Cell Line ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Mrna Level ◽  
Myelogenous Leukemia ◽  
Mrna Levels ◽  
Smad4 Protein ◽  
Tgf Β1

Abstract Smad4 is important in the TGF-β pathway and required for transcriptional activation and inhibition of cell growth after TGF-β1 stimulation. We demonstrate that miR-130a is differentially expressed during granulopoiesis and targets Smad4 mRNA. The transcript for Smad4 is present throughout neutrophil maturation, but Smad4 protein is undetectable in the most immature cells, where miR-130a is highly expressed. Two miR-130a binding sites were identified in the 3′-untranslated region of the Smad4 mRNA. Overexpression of miR-130a in HEK293, A549, and 32Dcl3 cells repressed synthesis of Smad4 protein without affecting Smad4 mRNA level. Repression of Smad4 synthesis in a granulocytic cell line by miR-130a reduced its sensitivity to TGF-β1–induced growth inhibition. This effect was reversed by inhibiting the activity of miR-130a with an antisense probe or by expressing a Smad4 mRNA lacking miR-130a binding sites. High endogenous miR-130a and Smad4 mRNA levels and low expression of Smad4 protein were found in the t(8;21)(q22;q22) acute myelogenous leukemia–derived cell line Kasumi-1. When miR-130a was inhibited by an antisense RNA, the amount of Smad4 protein increased in Kasumi-1 cells and rendered it susceptible for TGF-β1–mediated cell growth inhibition. Our data indicate that miR-130a is involved in cell cycle regulation of granulocytic cells through engagement of Smad4 in the TGF-β pathway.

Deferasirox Inhibit Doxorubicin-Induced Reactive Oxygen Species Generation in Both Acute Myeloid Leukemia and Normal Heart Cell While Maintain the Cytotoxicity of Doxorubicin Only on Acute Myeloid Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3620-3620
Author(s):  
Su-Peng Yeh ◽  
Yu-Chien Chang ◽  
Wen-Jyi Lo ◽  
Min-Lih Huang ◽  
Yang-Sheng Yang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Line ◽  
Myeloid Leukemia ◽  
Heart Cell ◽  
Ros Generation ◽  
Heart Cells ◽  
Normal Heart ◽  
Intracellular Ros ◽  
Induced Apoptosis ◽  
Acute Myeloid

Abstract Abstract 3620 Background: Deferasirox (DFX) was recently found to have anti-leukemia effect both in vitro and in vivo. DFX can also potently inhibit the generation of intracellular reactive oxygen species (ROS). On the other hand, the generation of ROS by Doxorubicin (DOX) is critical for the cytotoxicity on both leukemia and normal heart cells. It is not known whether combining DFX and DOX will have synergistic or antagonizing effect on leukemic cells. Similarly, it is also unknown whether adding DFX to DOX will have protective effect on normal heart cell. Method: Cells of human acute myeloid leukemia (AML) cell line THP1, mice AML cell line WEHI3, and rat normal heart cell line H9C2 were treated with Doxorubicin 5microM for various duration in the presence of absence of DFX pretreatment (100microM for 10 minutes). Intracellular ROS generation was measured by the detection of 2,7-dichlorodihydrofluorescein (DCF) fluorescence intensity using flow cytometry. Apoptosis was determined by Annexin V-Propidium Iodide staining using flow cytometry. Cytotoxicity was determined by Trypan blue exclusion assay. Results: Although intracellular ROS was reduced, DFX alone induced apoptosis of THP1 (from 3% to 18%) and WEHI3 (from 31% to 49%) AML cells. DOX-induced ROS production was also significantly reduced when THP1, WEHI3, and H9C2 cells were pretreated with DFX (Figure 1a, 1b, 1c respectively). However, the DOX-induced apoptosis of THP1 and WEHI3 AML cells were not antagonized by DFX (Figure 2a). 24 hours after exposure to this physiological dose DOX, all the WEHI3 cells died in both DFX treated or untreated group (figure 2b). More importantly, DFX-pretreated H9C2 heart cells had fewer cell death (3.7%) after exposure to DOX (5microM for 24 hours) compared to non-DFX pretreated cells (8.5%). Conclusions: DFX alone induced apoptosis in two different AML cell lines. DFX also markedly reduced the ROS generation due to DOX treatment. However, DFX did not negatively influence the pro-apoptotic and cytotoxic effect of DOX on these AML cell lines. Interestingly, DFX also markedly reduced the DOX-induced ROS generation and DOX-induced cell death in normal rat heart cell, which might have protective effect on DOX-related cardiomyopathy. We are now using Balb/c-WEHI3 AML mice model to test whether DFX can protect cardiomyocytes from DOX-related damage while maintain the cytotoxic effect of DOX on AML cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Role of nerve growth factor in the development of rat sympathetic neurons in vitro. III. Effect on acetylcholine production.

1977 ◽  
Vol 75 (3) ◽  
pp. 712-718 ◽  
Author(s):  
L L Chun ◽  
P H Patterson
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Rat Heart ◽  
Neuronal Survival ◽  
Sympathetic Neurons ◽  
Cell Monolayer ◽  
Heart Cell ◽  
Heart Cells ◽  
Nerve Growth ◽  
Rat Heart Cells

The effect of nerve growth factor (NGF) on the development of cholinergic sympathetic neurons was studied in cultures grown either on monolayers of dissociated rat heart cells or in medium conditioned by them. In the presence of rat heart cells the absolute requirement of neurons for exogenous NGF was partially spared. The ability of heart cells to support neuronal survival was due at least in part to production of a diffusable NGF-like substance into the medium. Although some neurons survived on the heart cell monolayer without added NGF, increased levels of exogenous NGF increased neuronal survival until saturation was achieved at 0.5 microgram/ml 7S NGF. The ability of neurons to produce acetylcholine (ACh) from choline was also dependent on the level of exogenous NGF. In mixed neuron-heart cell cultures, NGF increased both ACh and catecholamine (CA) production per neuron to the same extent; saturation occurred at 1 microgram/ml 7S NGF. As cholinergic neurons developed in culture, they became less dependent on NGF for survival and ACh production, but even in older cultures approximately 40% of the neurons died when NGF was withdrawn. Thus, NGF is as necessary for survival, growth, and differentiation of sympathetic neurons when the neurons express cholinergic functions as when the neurons express adrenergic functions (4, 5).

Expression and localization of renin and angiotensinogen in rat heart after myocardial infarction

1996 ◽  
Vol 271 (3) ◽  
pp. H1040-H1048 ◽  
Author(s):  
R. C. Passier ◽  
J. F. Smits ◽  
M. J. Verluyten ◽  
M. J. Daemen
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Hypertrophy ◽  
Rat Heart ◽  
Dominant Role ◽  
Rna Isolation ◽  
Fold Increase ◽  
Border Zone ◽  
Mrna Levels ◽  
Renin Mrna ◽  
Wistar Kyoto

Wistar-Kyoto rats underwent myocardial infarction (MI) or sham surgery. At different time points after surgery (1-90 days), hearts were removed and divided into infarcted left ventricle (LV), noninfarcted septum, and right ventricle. The tissues were used for total RNA isolation or Formalin fixation for in situ hybridization (ISH). Renin and angiotensinogen mRNA contents were quantified by the competitive reverse transcriptase polymerase chain reaction. We found a 4-, 14-, and 8-fold increase (P < 0.05, n = 6) in renin mRNA in the infarcted LV at 2, 4, and 7 days after MI, respectively. No differences were observed between angiotensinogen mRNA levels in sham and infarcted hearts. ISH at 4 days after surgery revealed a dense renin mRNA labeling around the infarcted area, whereas ISH of angiotensinogen displayed an overall low density in the myocardium with somewhat higher levels in the epicardium of sham and MI animals. Atrial natriuretic factor mRNA, a marker for cardiac hypertrophy, was approximately twofold higher in all compartments of the hearts after MI. The low amounts of renin and angiotensinogen mRNA in the noninfarcted hypertrophied myocardium indicate that the intracardiac synthesis of these components does not play a dominant role in the development of cardiac hypertrophy in the rat heart after MI. In addition, the increased renin mRNA expression in the border zone of the infarcted LV suggests a role for intracardiac angiotensin II in infarct healing.

The SCL-LMO2 Interaction Nucleates Hematopoietic Transcription Factor Complexes: Coupling Protein Stability and Complex Assembly.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 779-779
Author(s):  
Marie-Claude Sincennes ◽  
Eric Lecuyer ◽  
Simon Lariviere ◽  
Andre Haman ◽  
Rachid Lahlil ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Stability ◽  
Cell Line ◽  
Half Life ◽  
Gene Activation ◽  
Hematopoietic Cells ◽  
Mrna Levels ◽  
Protein Levels ◽  
Transcription Factor Complexes

Abstract The differentiation of hematopoietic cells is tightly controlled by transcription factor complexes, composed of hemato-specific and ubiquitous proteins. The bHLH factor SCL and the LIM-only protein LMO2 are central components of transcription factor complexes and are essential for hematopoiesis. However, the mechanism regulating the assembly of SCL-complexes is unknown. Here we show that SCL, in contrast to LMO, GATA and E proteins, cannot be replaced by other members of its family in hematopoietic gene transactivation and in gel shift assays. Furthermore, we show by GST pull-down assays and by co-immunoprecipitation that interaction with LMO2 is a unique property of SCL, as the neurogenic bHLH NSCL1 related to SCL cannot bind LMO2. By generating SCL-NSCL1 chimeras, and by phylogenetic alignment, we identified the SCL interface that confers transcriptional specificity to the complex. Strikingly, this interface is also necessary for the interaction with LMO2. In contrast with the wild type SCL, the mutant without this interface is not able to enhance erythroid differentiation when overexpressed in hematopoietic cells, as assessed by glycophorin A gene activation, benzidine staining and methylcellulose cultures. Interestingly, we also demonstrate in vivo and in vitro that LMO2 protein levels are greatly increased in the presence of SCL, while mRNA levels remain constant. When the SCL interface described above is mutated, LMO2 protein level is no longer increased, suggesting that the accumulation of LMO2 is mediated by a direct interaction with SCL. In primary hematopoietic cells, when SCL protein levels are genetically reduced by LacZ insertion into one allele in the SCL locus, we observe a dramatic decrease in LMO2 protein levels. In addition, in the TF-1 hematopoietic cell line, most of the LMO2 protein (90%) is found associated with SCL and/or Ldb1, suggesting that free LMO2 is rapidly degraded. Thus, SCL levels determine LMO2 levels in hematopoietic cells. Next, we provide direct evidence that LMO2 is a target for proteasomal degradation. First, we show that LMO2 is ubiquitinated in vivo, by GST purification. Second, by using the ts20 cell line expressing a temperature-sensitive ubiquitin-activating E1 enzyme, we show that LMO2 degradation requires a functional ubiquitin conjugation system, since LMO2 is not degraded when E1 is inactive. Third, we show that the half-life of LMO2 is very short, and it can be increased with the proteasome inhibitor MG132. Finally, a similar increase in LMO2 half-life can be observed when SCL is co-expressed with LMO2. These data indicate that SCL stabilizes LMO2, which is otherwise rapidly degraded by the ubiquitin-proteasome pathway in absence of its interacting partners. Taken together, our results strongly suggest that SCL, by binding and stabilizing LMO2, is a critical determinant of the hematopoietic transcriptional specificity. The interaction between SCL and LMO2 is an essential nucleation step for the assembly of SCL-complexes on DNA, where the regulation of LMO2 levels appears to be the rate-limiting step. We propose that protein stability is a new mechanism of regulation in the formation of SCL complexes, required for proper gene activation during eryhtroid differentiation.

scholarly journals Apolipoprotein CI overexpression is not a relevant strategy to block cholesteryl ester transfer protein (CETP) activity in CETP transgenic mice

2004 ◽  
Vol 385 (1) ◽  
pp. 189-195 ◽  
Author(s):  
Thomas GAUTIER ◽  
David MASSON ◽  
Miek C. JONG ◽  
Jean-Paul PAIS DE BARROS ◽  
Linda DUVERNEUIL ◽  
...  
Keyword(s):  
Cholesteryl Ester ◽  
Cholesteryl Ester Transfer Protein ◽  
Mrna Level ◽  
Fold Increase ◽  
Receptor Activation ◽  
Liver X Receptor ◽  
Mrna Levels ◽  
Transfer Protein ◽  
Transfer Activity

ApoCI (apolipoprotein CI) is a potent inhibitor of plasma CETP [CE (cholesteryl ester) transfer protein]. The relevance of apoCI overexpression as a method for CETP blockade in vivo was addressed in the present study in CETPTg/apoCITg mice (mice expressing both human CETP and apoCI). Despite a significant reduction in specific CETP activity in CETPTg/apoCITg mice compared with CETPTg mice [transgenic mouse to human CETP; 46.8±11.1 versus 101.8±25.7 pmol·h−1·(μg of plasma CETP)−1 respectively; P<0.05], apoCI overexpression increased both the CETP mass concentration (3-fold increase; P<0.05) and the hepatic CETP mRNA level (4-fold increase, P<0.005), leading to an increase in total plasma CE transfer activity (by 39%, P<0.05). The ratio of apoB-containing lipoprotein to HDL (high-density lipoprotein) CE was 10-fold higher in CETPTg/apoCITg mice than in apoCITg mice (P<0.0005). It is proposed that the increased CETP expression in CETPTg/apoCITg mice is a direct consequence of liver X receptor activation in response to the accumulation of cholesterol-rich apoB-containing lipoproteins. In support of the latter view, hepatic mRNA levels of other liver X receptor-responsive genes [ABCG5 (ATP-binding cassette transporter GS) and SREBP-1c (sterol-regulatory-binding protein-1c)] were higher in CETPTg/apoCITg mice compared with CETPTg mice. In conclusion, overexpression of apoCI, while producing a significant inhibitory effect on specific CETP activity, does not represent a suitable method for decreasing total CE transfer activity in CETPTg/apoCITg mice, owing to an hyperlipidaemia-mediated effect on CETP gene expression.

scholarly journals Establishment and characterization of the thrombopoietin-dependent megakaryocytic cell line, UT-7/TPO

Blood ◽  
1996 ◽  
Vol 87 (11) ◽  
pp. 4552-4560 ◽  
Author(s):  
N Komatsu ◽  
M Kunitama ◽  
M Yamada ◽  
T Hagiwara ◽  
T Kato ◽  
...  
Keyword(s):  
Cell Line ◽  
Mrna Level ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Mrna Levels ◽  
Platelet Factor ◽  
Growth And Survival ◽  
Megakaryoblastic Leukemia ◽  
Absolute Dependence ◽  
High Level

UT-7 is a human megakaryoblastic leukemia cell line with absolute dependence on interleukin-3, granulocyte-macrophage colony-stimulating factor, or erythropoietin (EPO) for growth and survival. We investigated the effect of thrombopoietin (TPO), the ligand for the receptor encoded by c-mpl proto-oncogene, on the proliferation and differentiation of UT-7 and its sublines. We found that UT-7/GM, which is a subline of UT-7, but neither UT-7 nor UT-7/EPO, can proliferate in response to TPO. The subline, UT-7/TPO, was established from UT-7/GM by culture at lower concentrations of TPO. UT-7/TPO cells had morphologically mature megakaryocytic characteristics such as developed demarcation membrane in the cytoplasm and multinucleated appearance. This was also confirmed by the high expression of platelet factor-4 and glycoprotein IIb at the mRNA levels and by the high level of DNA content. UT-7/TPO can be maintained by TPO alone, with a doubling time of 24 hours in log growth phase. In the absence of TPO, the majority of the cells died within a few days. Thus, UT-7/TPO has an absolute dependence on TPO for growth and survival and has mature megakaryocytic features. The mRNA for c-mpl was detected in UT-7/TPO and, to a lesser degree, in UT-7/GM. The mRNA level of NF- E2 p45, reported to be an erythroid-specific transcription factor, was upregulated in UT-7/TPO, whereas it was down-regulated in the erythroid subline, UT-7/EPO. There were no significant differences in GATA-1 and GATA-2 mRNA levels among UT-7 and its sublines. Not only EPO but also TPO induced the tyrosine phosphorylation of JAK2 tyrosine kinase and STAT5-related protein. These findings indicate that UT-7/TPO would be a useful model with which to analyze the gene regulation of megakaryocytic maturation- associated proteins and to study the specific actions of TPO.

scholarly journals Adenosine formation and release from neonatal-rat heart cells in culture

1985 ◽  
Vol 229 (3) ◽  
pp. 799-805 ◽  
Author(s):  
P Meghji ◽  
C A Holmquist ◽  
A C Newby
Keyword(s):  
Rat Heart ◽  
Neonatal Rat ◽  
Heart Cell ◽  
Heart Cells ◽  
Dependent Manner ◽  
Nucleoside Transporter ◽  
Concentration Dependent Manner ◽  
Cells In Culture ◽  
Neonatal Rat Heart ◽  
Rat Heart Cells

The incorporation of [3H]adenosine (10 microM) into neonatal-rat heart cell nucleotides was inhibited in a concentration-dependent manner, such that 50% inhibition was obtained with 0.75 microM-dipyridamole, 0.26 microM-hexobendine or 0.22 microM-dilazep. Adenosine formation was accelerated 2.5-fold to 2.1 +/- 0.3 nmol/10(7) cells in 10 min when cells were incubated with a combination of 30 mM-2-deoxyglucose and 2 micrograms of oligomycin/ml. Of the newly formed adenosine, 6 +/- 2% was in the cells. Dipyridamole, hexobendine or dilazep (10 microM) increased the amount of adenosine in the cells and decreased that in the medium such that 45-50% of the newly formed adenosine was in the cells. Antibodies which inhibited ecto-5'-nucleotidase by 98.7 +/- 0.3% did not alter the rate of adenosine formation or its distribution between cells and medium. We conclude that adenosine was formed in the cytoplasm during catabolism of cellular ATP and was released via the dipyridamole-sensitive symmetric nucleoside transporter.

Sign in / Sign up

Export Citation Format

Share Document