Triiodothyronine restricts myofibrillar growth and enhances beating frequency in cultured adult rat cardiomyocytes

1998 ◽  
Vol 93 (5) ◽  
pp. 391-395 ◽  
Author(s):  
M.C. Schaub ◽  
M.A. Hefti ◽  
B.A. Harder ◽  
H.M. Eppenberger
Keyword(s):  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Beating Frequency

scholarly journals IP3R1 regulates Ca2+ transport and pyroptosis through the NLRP3/Caspase-1 pathway in myocardial ischemia/reperfusion injury

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Guixi Mo ◽  
Xin Liu ◽  
Yiyue Zhong ◽  
Jian Mo ◽  
Zhiyi Li ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Cell Model ◽  
Ischemia Reperfusion ◽  
Inflammatory Factors ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Caspase 1 ◽  
Intracellular Ca ◽  
Myocardial Ischemia Reperfusion

AbstractIntracellular ion channel inositol 1,4,5-triphosphate receptor (IP3R1) releases Ca2+ from endoplasmic reticulum. The disturbance of IP3R1 is related to several neurodegenerative diseases. This study investigated the mechanism of IP3R1 in myocardial ischemia/reperfusion (MI/R). After MI/R modeling, IP3R1 expression was silenced in myocardium of MI/R rats to explore its role in the concentration of myocardial enzymes, infarct area, Ca2+ level, NLRP3/Caspase-1, and pyroptosis markers and inflammatory factors. The adult rat cardiomyocytes were isolated and cultured to establish hypoxia/reperfusion (H/R) cell model. The expression of IP3R1 was downregulated or ERP44 was overexpressed in H/R-induced cells. Nifedipine D6 was added to H/R-induced cells to block Ca2+ channel or Nigericin was added to activate NLRP3. IP3R1 was highly expressed in myocardium of MI/R rats, and silencing IP3R1 alleviated MI/R injury, reduced Ca2+ overload, inflammation and pyroptosis in MI/R rats, and H/R-induced cells. The binding of ERP44 to IP3R1 inhibited Ca2+ overload, alleviated cardiomyocyte inflammation, and pyroptosis. The increase of intracellular Ca2+ level caused H/R-induced cardiomyocyte pyroptosis through the NLRP3/Caspase-1 pathway. Activation of NLRP3 pathway reversed the protection of IP3R1 inhibition/ERP44 overexpression/Nifedipine D6 on H/R-induced cells. Overall, ERP44 binding to IP3R1 inhibits Ca2+ overload, thus alleviating pyroptosis and MI/R injury.

Ca2 Mobilization in Adult Rat Cardiomyocytes by Angiotensin Type 1 and 2 Receptors

1998 ◽  
Vol 55 (9) ◽  
pp. 1413-1418 ◽  
Author(s):  
Qiming Shao ◽  
Laura Saward ◽  
Peter Zahradka ◽  
Naranjan S Dhalla
Keyword(s):  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Angiotensin Type

Arachidonic acid mediates dual effect of TNF-α on Ca2+ transients and contraction of adult rat cardiomyocytes

2002 ◽  
Vol 282 (6) ◽  
pp. C1339-C1347 ◽  
Author(s):  
Aïssata Amadou ◽  
Artur Nawrocki ◽  
Martin Best-Belpomme ◽  
Catherine Pavoine ◽  
Françoise Pecker
Keyword(s):  
Arachidonic Acid ◽  
Cyclooxygenase Inhibitors ◽  
High Dose ◽  
Negative Effects ◽  
Dual Effect ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Tnf Α ◽  
Biphasic Effect

Tumor necrosis factor (TNF)-α has a biphasic effect on heart contractility and stimulates phospholipase A2 (PLA2) in cardiomyocytes. Because arachidonic acid (AA) exerts a dual effect on intracellular Ca2+ concentration ([Ca2+]i) transients, we investigated the possible role of AA as a mediator of TNF-α on [Ca2+]i transients and contraction with electrically stimulated adult rat cardiac myocytes. At a low concentration (10 ng/ml) TNF-α produced a 40% increase in the amplitude of both [Ca2+]i transients and contraction within 40 min. At a high concentration (50 ng/ml) TNF-α evoked a biphasic effect comprising an initial positive effect peaking at 5 min, followed by a sustained negative effect leading to 50–40% decreases in [Ca2+]i transients and contraction after 30 min. Both the positive and negative effects of TNF-α were reproduced by AA and blocked by arachidonyltrifluoromethyl ketone (AACOCF3), an inhibitor of cytosolic PLA2. Lipoxygenase and cyclooxygenase inhibitors reproduced the high-dose effects of TNF-α and AA. The negative effects of TNF-α and AA were also reproduced by sphingosine and were abrogated by the ceramidase inhibitor n-oleoylethanolamine. These results point out the key role of the cytosolic PLA2/AA pathway in mediating the contractile effects of TNF-α.

scholarly journals Adenoprotection of the heart involves phospholipase C-induced activation and translocation of PKC-ε to RACK2 in adult rat and mouse

2009 ◽  
Vol 297 (2) ◽  
pp. H718-H725 ◽  
Author(s):  
Richard A. Fenton ◽  
Satoshi Komatsu ◽  
Mitsuo Ikebe ◽  
Lynne G. Shea ◽  
James G. Dobson
Keyword(s):  
Confocal Microscopy ◽  
Phospholipase C ◽  
Adrenergic Agonist ◽  
Rat Cardiomyocytes ◽  
Scanning Confocal Microscopy ◽  
Adult Rat ◽  
Sds Page ◽  
T Tubules ◽  
Isolated Rat ◽  
Stimulation Of

Adenosine protects the heart from adrenergic overstimulation. This adenoprotection includes the direct anti-adrenergic action via adenosine A1 receptors (A1R) on the adrenergic signaling pathway. An indirect A1R-induced attenuation of adrenergic responsiveness involves the translocation of PKC-ε to t-tubules and Z-line of cardiomyocytes. We investigated with sarcomere imaging, immunocytochemistry imaging, and coimmunoprecipitation (co-IP) whether A1R activation of PKC-ε induces the kinase translocation to receptor for activated C kinase 2 (RACK2) in isolated rat and mouse hearts and whether phospholipase C (PLC) is involved. Rat cardiomyocytes were treated with the A1R agonist chlorocyclopentyladenosine (CCPA) and exposed to primary PKC-ε and RACK2 antibodies with secondaries conjugated to Cy3 and Cy5 (indodicarbocyanine), respectively. Scanning confocal microscopy showed that CCPA caused PKC-ε to reversibly colocalize with RACK2 within 3 min. Additionally, rat and mouse hearts were perfused and stimulated with CCPA or phenylisopropyladenosine to activate A1R, or with phorbol 12-myristate 13-acetate to activate PKC. RACK2 was immunoprecipitated from heart extracts and resolved with SDS-PAGE. Western blotting showed that CCPA, phenylisopropyladenosine, and phorbol 12-myristate 13-acetate in the rat heart increased the PKC-ε co-IP with RACK2 by 186, 49, and >1,000%, respectively. The A1R antagonist 8-cyclopentyl-1,3-dipropylxanthine prevented the CCPA-induced co-IP with RACK2. In mouse hearts, CCPA increased the co-IP of PKC-ε with RACK2 by 61%. With rat cardiomyocytes, the β-adrenergic agonist isoproterenol increased sarcomere shortening by 177%. CCPA reduced this response by 47%, an action inhibited by the PLC inhibitor U-73122 and 8-cyclopentyl-1,3-dipropylxanthine. In conclusion, A1R stimulation of the heart is associated with PLC-initiated PKC-ε translocation and association with RACK2.

scholarly journals Purinergic stimulation of rat cardiomyocytes induces tyrosine phosphorylation and membrane association of phospholipase Cγ: a major mechanism for InsP3 generation

1996 ◽  
Vol 318 (2) ◽  
pp. 723-728 ◽  
Author(s):  
Michel PUCEAT ◽  
Guy VASSORT
Keyword(s):  
Tyrosine Kinase ◽  
Time Course ◽  
Kinase Inhibitor ◽  
Extracellular Atp ◽  
Rat Cardiomyocytes ◽  
Major Mechanism ◽  
Adult Rat ◽  
Hydrolysis Of ◽  
Purinergic Stimulation ◽  
Stimulation Of

Phospholipase Cγ (PLCγ) expression and activation by a purinergic agonist were investigated in adult rat cardiomyocytes. PLCγ is expressed in isolated cardiomyocytes. Stimulation of cells with extracellular ATP induces a rapid increase in membrane-associated PLCγ immunoreactivity most probably due to redistribution of the lipase from the cytosol to the membrane. The purine triggers a significant phosphorylation on tyrosine residues of a cytosolic pool of PLCγ with a time course that correlates with that of translocation. Extracellular ATP also increases intracellular Ins(1,4,5)P3 content. All these events (translocation and phosphorylation of PLCγ, InsP3 formation) are blocked by genistein, a tyrosine kinase inhibitor. The purinergic effect on both PLCγ translocation and phosphorylation are Ca-sensitive. We thus propose that the purinergic stimulation activates a non-receptor tyrosine kinase that phosphorylates PLCγ in the presence of an increased Ca level and induces PLCγ redistribution to the membrane. There, PLCγ becomes activated leading to the hydrolysis of phosphatidylinositol diphosphate and in turn Ins(1,4,5)P3 formation. This cascade of events may play a significant role in the induction of arrhythmogenesis by purinergic agonists.

Hyperthyroid adult rat cardiomyocytes. I. Nucleotide content, beta- and alpha-adrenoreceptors, and cAMP production

1989 ◽  
Vol 257 (5) ◽  
pp. C948-C956 ◽  
Author(s):  
C. M. Hohl ◽  
S. Wetzel ◽  
R. H. Fertel ◽  
D. K. Wimsatt ◽  
G. P. Brierley ◽  
...  
Keyword(s):  
Ventricular Myocytes ◽  
Adenine Nucleotide ◽  
Phosphodiesterase Inhibitor ◽  
Cardiac Cells ◽  
Beta Agonist ◽  
Camp Production ◽  
Adult Rats ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Half Maximal Effective Concentration

Ventricular myocytes isolated from the hypertrophied hearts of thyrotoxic adult rats have an increase in mean protein content per myocyte (6.3 +/- 0.2 vs. 4.4 +/- 0.2 ng) compared with euthyroid cells. Viability and adenine nucleotide profiles are similar in both populations, but NAD content of the hyperthyroid myocytes is depressed (4.9 +/- 0.2 vs. 5.5 +/- 0.2 nmol/mg for controls) and UTP is higher (1.2 +/- 0.09 vs. 0.9 +/- 0.04 nmol/mg). Binding of (-)-[125I]iodocyanopindolol to intact hyperthyroid myocytes is increased by 42% compared with controls, with no change in the dissociation constant (Kd). This elevation in beta-receptor number is correlated to enhanced beta-agonist-induced adenosine 3',5'-cyclic monophosphate (cAMP) production. The half-maximal effective concentration (EC50) for the euthyroid isoproterenol dose-response curve is 2.14 x 10(-7) M but is decreased to 2.51 x 10(-8) M in hyperthyroid cardiac cells. Basal adenylate cyclase activity is apparently not affected by thyroid hormones, since basal cAMP levels for both groups are identical (5 pmol/mg) and both rise roughly twofold in the presence of a phosphodiesterase inhibitor. Forskolin-induced cAMP production and cAMP-specific phosphodiesterase activity are similar as well. In contrast to beta-adrenergic response, there are no significant differences in alpha 1-antagonist [3H]prazosin binding parameters between hyperthyroid and euthyroid cardiomyocytes.

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