Measurement of Free Intracellular Calcium (Cai) in Fibroblasts

1989 ◽  
pp. 239-248 ◽  
Author(s):  
R. W. Tucker ◽  
K. Meade-Cobun ◽  
H. Loats
Keyword(s):  
Intracellular Calcium ◽  
Free Intracellular Calcium

Free Intracellular Calcium in Aging and Alzheimer's Disease

1996 ◽  
Vol 786 (1 Near-Earth Ob) ◽  
pp. 305-320 ◽  
Author(s):  
WALTER E. MÜLLER ◽  
HENRIKE HARTMANN ◽  
ANNE ECKERT ◽  
KARSTEN VELBINGER ◽  
HANS FöRSTL
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Intracellular Calcium ◽  
Free Intracellular Calcium

Down-regulation of free intracellular calcium in dissociated brain cells of aged mice and rats

Life Sciences ◽  
1996 ◽  
Vol 59 (5-6) ◽  
pp. 435-449 ◽  
Author(s):  
Henrike Hartmann ◽  
Anne Eckert ◽  
Karsten Velbinger ◽  
Michael Rewsin ◽  
Walter E. Müller
Keyword(s):  
Intracellular Calcium ◽  
Brain Cells ◽  
Down Regulation ◽  
Aged Mice ◽  
Free Intracellular Calcium ◽  
Dissociated Brain Cells

Lowering the stimulated free intracellular calcium level in platelets in the refractory state

1988 ◽  
Vol 106 (6) ◽  
pp. 1699-1702
Author(s):  
E. Ya. Pozin ◽  
E. G. Popov ◽  
I. Yu. Gavrilov ◽  
Z. A. Gabbasov ◽  
S. N. Krotov
Keyword(s):  
Intracellular Calcium ◽  
Calcium Level ◽  
Intracellular Calcium Level ◽  
Free Intracellular Calcium ◽  
Refractory State

scholarly journals Human recombinant interferon gamma enhances neonatal polymorphonuclear leukocyte activation and movement, and increases free intracellular calcium.

1991 ◽  
Vol 173 (3) ◽  
pp. 767-770 ◽  
Author(s):  
H R Hill ◽  
N H Augustine ◽  
H S Jaffe
Keyword(s):  
Intracellular Calcium ◽  
Interferon Gamma ◽  
Messenger Rna ◽  
Intrinsic Defect ◽  
Mononuclear Leukocytes ◽  
Developmental Defect ◽  
Phagocytic Cells ◽  
Ifn Gamma ◽  
Recombinant Interferon ◽  
Free Intracellular Calcium

In previous studies, we have reported that after chemotactic factor stimulation, PMNs from neonates fail to undergo certain critical activation steps. Furthermore, the concentration of free intracellular calcium reached is significantly below that of PMNs from adults. Interferon-gamma (IFN-gamma) is a lymphokine that has been shown to activate phagocytic cells, and IFN-gamma messenger RNA production by neonatal mononuclear leukocytes has been reported to be depressed. In the present studies, we found that recombinant human IFN-gamma markedly enhanced the chemotactic responses of PMNs from neonates to levels that were not different from that of PMNs from adults. Furthermore, preincubation of the neonatal cells with this recombinant human lymphokine also corrected the abnormality in intracellular calcium metabolism. These results suggest that this developmental defect in phagocytic cell movement may be the result of an intrinsic defect in IFN-gamma production resulting in deficiency of this critical phagocyte-activating lymphokine.

PGE2 attenuates PGF2α-induced increases in free intracellular calcium in ovine large luteal cells

1993 ◽  
Vol 45 (2) ◽  
pp. 167-176 ◽  
Author(s):  
G.J. Wiepz ◽  
M.C. Wiltbank ◽  
S.B. Kater ◽  
G.D. Niswender ◽  
H.R. Sawyer
Keyword(s):  
Intracellular Calcium ◽  
Luteal Cells ◽  
Free Intracellular Calcium

Diffusion, Buffering, and Binding

1998 ◽  
Author(s):  
Christof Koch
Keyword(s):  
Synaptic Plasticity ◽  
Intracellular Calcium ◽  
Temporal Dynamics ◽  
Critical Concentration ◽  
Two Photon Microscopy ◽  
Calcium Dependent ◽  
Calcium Sensors ◽  
Free Intracellular Calcium ◽  
Messenger Molecules ◽  
Spatio Temporal

In Chap. 9 we introduced calcium ions and alluded to their crucial role in regulating the day-to-day life of neurons. The dynamics of the free intracellular calcium is controlled by a number of physical and chemical processes, foremost among them diffusion and binding to a host of different proteins, which serve as calcium buffers and as calcium sensors or triggers. Whereas buffers simply bind Ca2+ above some critical concentration, releasing it back into the cytoplasm when [Ca2+]i has been reduced below this level, certain proteins— such as calmodulin—change their conformation when they bind with Ca2+ ions, thereby activating or modulating enzymes, ionic channels, or other proteins. The calcium concentration inside the cell not only determines the degree of activation of calcium-dependent potassium currents but—much more importantly—is relevant for determining the changes in structure expressed in synaptic plasticity. As discussed in Chap. 13, it is these changes that are thought to underlie learning. Given the relevance of second messenger molecules, such as Ca2+, IP3, cyclic AMP and others, for the processes underlying growth, sensory adaptation, and the establishment and maintenance of synaptic plasticity, it is crucial that we have some understanding of the role that diffusion and chemical kinetics play in governing the behavior of these substances. Today, we have unprecedented access to the spatio-temporal dynamics of intracellular calcium in individual neurons using fluorescent calcium dyes, such as fura-2 or fluo-3, in combination with confocal or two-photon microscopy in the visible or in the infrared spectrum (Tsien, 1988; Tank et al., 1988; Hernández-Cruz, Sala, and Adams, 1990; Ghosh and Greenberg, 1995).

Axotomy induces a transient and localized elevation of the free intracellular calcium concentration to the millimolar range

1995 ◽  
Vol 74 (6) ◽  
pp. 2625-2637 ◽  
Author(s):  
N. E. Ziv ◽  
M. E. Spira
Keyword(s):  
Intracellular Calcium ◽  
Calcium Concentration ◽  
Intracellular Calcium Concentration ◽  
Concentration Gradients ◽  
Fura 2 ◽  
Direct Demonstration ◽  
Free Intracellular Calcium ◽  
Axonal Transection ◽  
Transient Elevation

1. Axonal transection triggers a cascade of pathological processes that frequently lead to the degeneration of the injured neuron. It is generally believed that the degenerative process is triggered by an overwhelming influx of calcium through the cut end of the axon. 2. Theoretical considerations and indirect observations suggest that axotomy is followed by an increase in the free intracellular calcium concentration ([Ca2+]i) to the millimolar level. In contrast, only relatively modest and transient elevation in [Ca2+]i to the micromolar level was revealed by recent fura-2 studies. 3. In the current study we used the low-affinity Ca2+ indicator mag-fura-2 to reexamine the spatiotemporal distribution pattern of Ca2+ after axotomy and to map the free intracellular Mg2+ concentration gradients. 4. We report that axotomy elevates [Ca2+]i well beyond the "physiological" range of calcium concentrations, to levels > 1 mM near the tip of the cut axon and to hundreds of micromolars along the axon further away from the cut end. Nevertheless, [Ca2+]i recovers to the control levels within 2-3 min after the resealing of the cut end. 5. A comparison of the behavior of fura-2 and mag-fura-2 in the cytosol of the axotomized neurons reveals that the determination of [Ca2+]i by fura-2 largely underestimates the actual intracellular Ca2+ concentrations. 6. Experiments in which one branch of a bifurcated axon was transected revealed that the elevation in [Ca2+]i is confined to the transected axonal branch and does not spread beyond the bifurcation point. 7. After axotomy, the intracellular Mg2+ concentration equilibrates rapidly with the external concentration and then recovers at a rate somewhat slower than that of [Ca2+]i. 8. To the best of our knowledge, this study is the first direct demonstration that axotomy elevates [Ca2+]i to the millimolar range and that neurons are able to recover from these extreme calcium concentrations.

scholarly journals Mechanisms underlying oocyte activation and postovulatory ageing

Reproduction ◽  
2002 ◽  
pp. 745-754 ◽  
Author(s):  
RA Fissore ◽  
M Kurokawa ◽  
J Knott ◽  
M Zhang ◽  
J Smyth
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Intracellular Calcium ◽  
Oocyte Maturation ◽  
Abnormal Development ◽  
Oocyte Activation ◽  
Molecular Changes ◽  
Free Intracellular Calcium ◽  
Developmental Programme ◽  
Nuclear Modifications

Mammalian oocytes undergo significant growth during oogenesis and experience extensive cytoplasmic and nuclear modifications immediately before ovulation in a process commonly referred to as oocyte maturation. These changes are intended to maximize the developmental success after fertilization. Entry of a spermatozoon into the oocyte, which occurs a few hours after ovulation, initiates long-lasting oscillations in the free intracellular calcium ([Ca(2+)](i)) that are responsible for all events of oocyte activation and the initiation of the developmental programme that often culminates in the birth of young. Nevertheless, the cellular and molecular changes that occur during maturation to optimize development are transient, and exhibit rapid deterioration. Moreover, fertilization of oocytes after an extended residence in the oviduct (or in culture) initiates a different developmental programme, one that is characterized by fragmentation, programmed cell death, and abnormal development. Inasmuch as [Ca(2+)](i) oscillations can trigger both developmental programmes in mammalian oocytes, this review addresses one of the mechanism(s) possibly used by spermatozoa to initiate these persistent [Ca(2+)](i) responses, and the cellular and molecular changes that may underlie the postovulatory cellular fragmentation of ageing mammalian oocytes.

Region-specific downregulation of free intracellular calcium in the aged rat brain

1996 ◽  
Vol 17 (4) ◽  
pp. 557-563 ◽  
Author(s):  
Henrike Hartmann ◽  
Karsten Velbinger ◽  
Anne Eckert ◽  
Walter E. Müller
Keyword(s):  
Intracellular Calcium ◽  
Rat Brain ◽  
Aged Rat ◽  
Free Intracellular Calcium
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