scholarly journals Expressed Ryanodine Receptor Can Substitute for the Inositol 1,4,5-Trisphosphate Receptor inXenopus laevisOocytes during Progesterone-Induced Maturation

1995 ◽  
Vol 172 (2) ◽  
pp. 531-540 ◽  
Author(s):  
Evgeny Kobrinsky ◽  
Karol Ondrias ◽  
Andrew R. Marks
Keyword(s):  
Ryanodine Receptor ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

Effect of halothane on intracellular calcium oscillations in porcine tracheal smooth muscle cells

1999 ◽  
Vol 276 (1) ◽  
pp. L81-L89 ◽  
Author(s):  
Christina M. Pabelick ◽  
Y. S. Prakash ◽  
Mathur S. Kannan ◽  
Keith A. Jones ◽  
David O. Warner ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Ryanodine Receptor ◽  
Muscle Cells ◽  
Calcium Oscillations ◽  
Tracheal Smooth Muscle ◽  
Permeabilized Cells ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca ◽  
Trisphosphate Receptor

The effect of halothane on intracellular Ca2+ concentration ([Ca2+]i) regulation in porcine tracheal smooth muscle cells was examined with real-time confocal microscopy. Both 1 and 2 minimum alveolar concentration (MAC) halothane increased basal [Ca2+]iwhen Ca2+ influx and efflux were blocked, suggesting increased sarcoplasmic reticulum (SR) Ca2+ leak and/or decreased reuptake. In β-escin-permeabilized cells, heparin inhibition of inositol 1,4,5-trisphosphate-receptor channels blunted the halothane-induced increase in [Ca2+]i. Both 1 and 2 MAC halothane decreased the frequency and amplitude of ACh-induced [Ca2+]ioscillations (which represent SR Ca2+ release through ryanodine-receptor channels), abolishing oscillations in ∼20% of tracheal smooth muscle cells at 2 MAC. When Ca2+ influx and efflux were blocked, halothane increased the baseline and decreased the frequency and amplitude of [Ca2+]ioscillations, inhibiting oscillations in ∼70% of cells at 2 MAC. The fall time of [Ca2+]ioscillations and the rate of fall of the [Ca2+]iresponse to caffeine were both increased by halothane. These results suggest that halothane abolishes agonist-induced [Ca2+]ioscillations by 1) depleting SR Ca2+ via increased Ca2+ leak through inositol 1,4,5-trisphosphate-receptor channels, 2) decreasing Ca2+ release through ryanodine-receptor channels, and 3) inhibiting reuptake.

Inositol 1,4,5-trisphosphate receptor and ryanodine receptor in the aging brain of Wistar rats

1994 ◽  
Vol 15 (2) ◽  
pp. 203-206 ◽  
Author(s):  
Adelina Martini ◽  
Fiorenzo Battaini ◽  
Stefano Govoni ◽  
Pompeo Volpe
Keyword(s):  
Ryanodine Receptor ◽  
Wistar Rats ◽  
Aging Brain ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

Increase of cGMP, cADP-ribose and inositol 1,4,5-trisphosphate preceding Ca2+ transients in fertilization of sea urchin eggs

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4405-4414 ◽  
Author(s):  
Ritsu Kuroda ◽  
Kenji Kontani ◽  
Yasunari Kanda ◽  
Toshiaki Katada ◽  
Takashi Nakano ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Sea Urchin ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Sea Urchin Eggs ◽  
Direct Measurements ◽  
Cyclic Adp Ribose ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor ◽  
Receptor Channel

Transient increases, or oscillations, of cytoplasmic free Ca2+ concentration, [Ca2+]i, occur during fertilization of animal egg cells. In sea urchin eggs, the increased Ca2+ is derived from intracellular stores, but the principal signaling and release system involved has not yet been agreed upon. Possible candidates are the inositol 1,4,5-trisphosphate receptor/channel (IP3R) and the ryanodine receptor/channel (RyR) which is activated by cGMP or cyclic ADP-ribose (cADPR). Thus, it seemed that direct measurements of the likely second messenger candidates during sea urchin fertilization would be essential to an understanding of the Ca2+ signaling pathway. We therefore measured the cGMP, cADPR and inositol 1,4,5-trisphosphate (IP3) contents of sea urchin eggs during the early stages of fertilization and compared these with the [Ca2+]i rise in the presence or absence of an inhibitor against soluble guanylate cyclase. We obtained three major experimental results: (1) cytosolic cGMP levels began to rise first, followed by cADPR and IP3 levels, all almost doubling before the explosive increase of [Ca2+]i; (2) most of the rise in IP3 occurred after the Ca2+ peak; IP3 production could also be induced by the artificial elevation of [Ca2+]i, suggesting the large increase in IP3 is a consequence, rather than a cause, of the Ca2+ transient; (3) the measured increase in cGMP was produced by the soluble guanylate cyclase of eggs, and inhibition of soluble guanylate cyclase of eggs diminished the production of both cADPR and IP3 and the [Ca2+]i increase without the delay of Ca2+ transients. Taken together, these results suggest that the RyR pathway involving cGMP and cADPR is not solely responsible for the initiating event, but contributes to the Ca2+ transients by stimulating IP3 production during fertilization of sea urchin eggs.

scholarly journals Differential Intracellular Distributions of Inositol Trisphosphate and Ryanodine Receptors Within and Among Hematopoietic Cells

2005 ◽  
Vol 53 (7) ◽  
pp. 913-916 ◽  
Author(s):  
Andrea J. Clark ◽  
Howard R. Petty
Keyword(s):  
Ryanodine Receptor ◽  
Immunofluorescence Microscopy ◽  
Ryanodine Receptors ◽  
Hematopoietic Cells ◽  
Cell Integrity ◽  
Fixation Methods ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca ◽  
A Cell ◽  
Trisphosphate Receptor

To better understand the mechanism(s) of leukocyte Ca2+ signaling, we have studied the intracellular locations of two Ca2+-mobilizing receptors, the inositol 1,4,5-trisphosphate receptor and ryanodine receptor, by immunofluorescence microscopy. Our results show that localization differs not only between receptor classes within a cell, but among leukocyte types as well. We also illustrate the importance of preserving labile cellular filaments in maintaining cell integrity by fixation with the Safiejko-Mroczka and Bell protocol, because conventional fixation methods distort receptor patterns. We suggest that the observed differences influence intracellular Ca2+ signaling.

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