scholarly journals Calcium modulation of inositol 1,4,5-trisphosphate-induced calcium release from neuroblastoma x glioma hybrid (NG108-15) microsomes.

1986 ◽  
Vol 261 (35) ◽  
pp. 16414-16420
Author(s):  
T Jean ◽  
C B Klee
Keyword(s):  
Calcium Release ◽  
Calcium Modulation ◽  
Inositol 1,4,5 Trisphosphate

scholarly journals Nonlinear Dynamic Modeling of 2-Dimensional Interdependent Calcium and Inositol 1,4,5-Trisphosphate in Cardiac Myocyte

2019 ◽  
Vol 14 (1) ◽  
pp. 290-305 ◽  
Author(s):  
N. Singh ◽  
N. Adlakha
Keyword(s):  
Cardiac Myocyte ◽  
Calcium Release ◽  
Feedback Regulation ◽  
Calcium Oscillations ◽  
The Body ◽  
Calcium Dependent ◽  
Coupled Equations ◽  
Calcium Modulation ◽  
Inositol 1,4,5 Trisphosphate ◽  
The Impact

Calcium (Ca2+) and inositol 1,4,5-trisphosphate (IP3) is critically important actors for a vast array of cellular processes. The most significant of the functions is One of the main functions is communication in all parts of the body which is achieved through cell signaling. Abnormalities in Ca2+signaling have been implicated in clinically important conditions such as heart failure and cardiac arrhythmias. We propose a mathematical model which systematically investigates complex Ca2+and IP3dynamics in cardiac myocyte. This two dimensional model is based on calcium-induced calcium release via inositol 1,4,5-trisphosphate receptors and includes calcium modulation of IP3levels through feedback regulation of degradation and production. Forward-Time Centered-Space method has been used to solve the coupled equations. We were able to reproduce the observed oscillatory patterns in Ca2+as well as IP3signals. The model predicts that calcium-dependent production and degradation of IP3is a key mechanism for complex calcium oscillations in cardiac myocyte. The impact and sensitivity of source, leak, diffusion coefficients on both Ca2+and IP3dynamics have been investigated. The results show that the relationship between Ca2+and IP3dynamics is nonlinear.

scholarly journals Characterization of the inositol 1,4,5-trisphosphate-induced calcium release from permeabilized endocrine cells and its inhibition by decavanadate and p-hydroxymercuribenzoate

1989 ◽  
Vol 262 (1) ◽  
pp. 83-89 ◽  
Author(s):  
K J Föhr ◽  
J Scott ◽  
G Ahnert-Hilger ◽  
M Gratzl
Keyword(s):  
Endocrine Cells ◽  
Calcium Release ◽  
Cell Types ◽  
Inhibitory Effect ◽  
Maximal Effect ◽  
Thiol Compounds ◽  
Inositol 1,4,5 Trisphosphate ◽  
Dependent Inhibition ◽  
Pheochromocytoma Pc12 ◽  
First Time

The inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ compartment of endocrine cells was studied with alpha-toxin- and digitonin-permeabilized rat insulinoma (RINA2) and rat pheochromocytoma (PC12) cells. The Ca2+ uptake was ATP-dependent, and submicromolar concentrations of IP3 specifically released the stored Ca2+. Half-maximal Ca2+ release was observed with 0.25-0.5 mumol of IP3/l, and the amount of Ca2+ released due to IP3 could be enhanced by additional loading of the Ca2+ compartment. Consecutive additions of the same concentration of IP3 for 1-2 h always released the same amount of Ca2+ without desensitization, providing an ideal basis to further characterize the IP3-induced Ca2+ release. Here we describe for the first time a reversible inhibitory effect of decavanadate on the IP3-induced Ca2+ release. Among the vanadium species tested (decavanadate, oligovanadate and monovanadate), only decavanadate was inhibitory, with a half-maximal effect at 5 mumol/l in both cell types. The effect of decavanadate could be overcome by increasing the amount of sequestered Ca2+ or added IP3. Decavanadate did not affect the ATP-driven Ca2+ uptake but oligovanadate was inhibitory on Ca2+ uptake. p-Hydroxymercuribenzoate (pHMB) at concentrations between 10 and 30 mumol/l also inhibited the Ca2+ release due to IP3. Thiol compounds such as dithiothreitol (DTT; 1 mmol/l) added before pHMB removed all its inhibitory effect on the IP3-induced Ca2+ release, whereas the inhibition caused by decavanadate was unaffected by DTT. Thus, the decavanadate-dependent inhibition functions by a distinctly different mechanism than pHMB and could serve as a specific tool to analyse various aspects of the IP3-induced Ca2+ release within endocrine cells.

Differential modulation of caffeine- and IP3-induced calcium release in cultured arterial tissue

1999 ◽  
Vol 276 (5) ◽  
pp. C1115-C1120 ◽  
Author(s):  
Karl Dreja ◽  
Per Hellstrand
Keyword(s):  
Calcium Release ◽  
Cyclopiazonic Acid ◽  
Differential Modulation ◽  
Transient Responses ◽  
Inositol 1,4,5 Trisphosphate ◽  
Arterial Tissue ◽  
Intracellular Ca ◽  
Rat Tail

To investigate the Ca2+-dependent plasticity of sarcoplasmic reticulum (SR) function in vascular smooth muscle, transient responses to agents releasing intracellular Ca2+ by either ryanodine (caffeine) ord- myo-inositol 1,4,5-trisphosphate [IP3; produced in response to norepinephrine (NE), 5-hydroxytryptamine (5-HT), arginine vasopressin (AVP)] receptors in rat tail arterial rings were evaluated after 4 days of organ culture. Force transients induced by all agents were increased compared with those induced in fresh rings. Stimulation by 10% FCS during culture further potentiated the force and Ca2+ responses to caffeine (20 mM) but not to NE (10 μM), 5-HT (10 μM), or AVP (0.1 μM). The effect was persistent, and SR capacity was not altered after reversible depletion of stores with cyclopiazonic acid. The effects of serum could be mimicked by culture in depolarizing medium (30 mM K+) and blocked by the addition of verapamil (1 μM) or EGTA (1 mM) to the medium, lowering intracellular Ca2+ concentration ([Ca2+]i) during culture. These results show that modulation of SR function can occur in vitro by a mechanism dependent on long-term levels of basal [Ca2+]iand involving ryanodine- but not IP3 receptor-mediated Ca2+release.

scholarly journals Effect of adenine nucleotides on myo-inositol-1,4,5-trisphosphate-induced calcium release

1997 ◽  
Vol 325 (3) ◽  
pp. 661-666 ◽  
Author(s):  
Ludwig MISSIAEN ◽  
Jan B. PARYS ◽  
Humbert DE SMEDT ◽  
Ilse SIENAERT ◽  
Henk SIPMA ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Binding Site ◽  
Calcium Release ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Release Process ◽  
A7r5 Cells ◽  
Channel Opening ◽  
Inositol 1,4,5 Trisphosphate

The effects of a whole series of adenine nucleotides on Ins(1,4,5)P3-induced Ca2+ release were characterized in permeabilized A7r5 smooth-muscle cells. Several adenine nucleotides activated the Ins(1,4,5)P3 receptor. It was observed that 3′-phosphoadenosine 5′-phosphosulphate, CoA, di(adenosine-5′)tetraphosphate (Ap4A) and di(adenosine-5′)pentaphosphate (Ap5A) were more effective than ATP. Ap4A and Ap5A also interacted with a lower EC50 than ATP. In order to find out how these adenine nucleotides affected Ins(1,4,5)P3-induced Ca2+ release, we have measured their effect on the response of permeabilized A7r5 cells to a progressively increasing Ins(1,4,5)P3 concentration. Stimulatory ATP and Ap5A concentrations had no effect on the threshold Ins(1,4,5)P3 concentration for initiating Ca2+ release, but they stimulated Ca2+ release in the presence of supra-threshold Ins(1,4,5)P3 concentrations by increasing the co-operativity of the release process. Inhibition of the Ins(1,4,5)P3-induced Ca2+ release at higher ATP concentrations was associated with a further increase in co-operativity and also with a shift in threshold towards higher Ins(1,4,5)P3 concentrations. ATP had no effect on the non-specific Ca2+ leak in the absence of Ins(1,4,5)P3. We conclude that the adenine-nucleotide-binding site can be activated by many different adenine nucleotides. Binding of these compounds to the transducing domain of the Ins(1,4,5)P3 receptor increases the efficiency of transmitting Ins(1,4,5)P3 binding to channel opening. The inhibition by high ATP concentrations is exerted at a different site, related to Ins(1,4,5)P3 binding.

Calcium as a coagonist of inositol 1,4,5-trisphosphate-induced calcium release

Science ◽  
1991 ◽  
Vol 252 (5004) ◽  
pp. 443-446 ◽  
Author(s):  
E. Finch ◽  
T. Turner ◽  
S. Goldin
Keyword(s):  
Calcium Release ◽  
Inositol 1,4,5 Trisphosphate

scholarly journals Inositol 1,4,5-Trisphosphate Receptors in Human Disease: A Comprehensive Update

2020 ◽  
Vol 9 (4) ◽  
pp. 1096
Author(s):  
Jessica Gambardella ◽  
Angela Lombardi ◽  
Marco Bruno Morelli ◽  
John Ferrara ◽  
Gaetano Santulli
Keyword(s):  
Human Disease ◽  
Calcium Release ◽  
Current Knowledge ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Loss Of Function ◽  
Genome Wide ◽  
Inositol 1,4,5 Trisphosphate ◽  
Human Disorders

Inositol 1,4,5-trisphosphate receptors (ITPRs) are intracellular calcium release channels located on the endoplasmic reticulum of virtually every cell. Herein, we are reporting an updated systematic summary of the current knowledge on the functional role of ITPRs in human disorders. Specifically, we are describing the involvement of its loss-of-function and gain-of-function mutations in the pathogenesis of neurological, immunological, cardiovascular, and neoplastic human disease. Recent results from genome-wide association studies are also discussed.

Partial calcium release in response to submaximal inositol 1,4,5-trisphosphate receptor activation

1994 ◽  
Vol 98 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Ludwig Missiaen ◽  
Jan B. Parys ◽  
Humbert De Smedt ◽  
Masahiro Oike ◽  
Rik Casteels
Keyword(s):  
Calcium Release ◽  
Receptor Activation ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor
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