CONTROL OF MUSCLE RYANODINE RECEPTOR CALCIUM RELEASE CHANNELS BY PROTEINS IN THE SARCOPLASMIC RETICULUM LUMEN

Cyclic ADP-ribose (cADPR), an endogenous metabolite of beta-NAD+, activates Ca2+ release from endoplasmic reticulum in sea urchin eggs via the ryanodine receptor (RyR) pathway. A similar role has been proposed in cardiac sarcoplasmic reticulum (SR), although this remains controversial. We therefore investigated the ability of cADPR to induce Ca2+ release from canine cardiac SR microsomes using fluo 3 to monitor extravesicular Ca2+ concentration. We found that cADPR induced Ca2+ release in a concentration-dependent manner, whereas neither its precursor, NAD+, nor its metabolite, ADP-ribose, elicited a consistent effect. In addition, an additive effect on calcium release between cADPR and 9-Me-7-Br-eudistomin-D (MBED), an activator of RyR, was found as well as no cross-desensitization between cADPR and MBED. Specific blockers of the RyR did not abolish the cADPR-induced Ca2+ release. These results provide evidence for cADPR-induced Ca2+ release from dog cardiac SR via a novel mechanism which is independent of RyR activation.

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708 Loss of ryanodine receptor calcium release channels in Alzheimer's disease brain

Neurobiology of Aging ◽

10.1016/s0197-4580(96)80710-x ◽

1996 ◽

Vol 17 (4) ◽

pp. S176 ◽

Cited By ~ 1

Author(s):

C. O' Neill ◽

M. Kelliher ◽

R. Ravid

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Ryanodine Receptor ◽

Calcium Release ◽

Calcium Release Channels

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Effect of flecainide derivatives on sarcoplasmic reticulum calcium release suggests a lack of direct action on the cardiac ryanodine receptor

British Journal of Pharmacology ◽

10.1111/bph.13521 ◽

2016 ◽

Vol 173 (15) ◽

pp. 2446-2459 ◽

Cited By ~ 5

Author(s):

Mark L Bannister ◽

Anita Alvarez‐Laviada ◽

N Lowri Thomas ◽

Sammy A Mason ◽

Sharon Coleman ◽

...

Keyword(s):

Sarcoplasmic Reticulum ◽

Ryanodine Receptor ◽

Calcium Release ◽

Direct Action ◽

Sarcoplasmic Reticulum Calcium ◽

Cardiac Ryanodine Receptor

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Luminal calcium regulation of calcium release from sarcoplasmic reticulum

Bioscience Reports ◽

10.1007/bf01788370 ◽

1995 ◽

Vol 15 (5) ◽

pp. 387-397 ◽

Cited By ~ 19

Author(s):

Cecilia Hidalgo ◽

Paulina Donoso

Keyword(s):

Sarcoplasmic Reticulum ◽

Calcium Concentration ◽

Calcium Release ◽

Single Channel ◽

Release Rates ◽

Calcium Release Channels ◽

Channel Opening ◽

Inositol 1,4,5 Trisphosphate ◽

Luminal Calcium ◽

Trisphosphate Receptor

This article discusses how changes in luminal calcium concentration affect calcium release rates from triad-enriched sarcoplasmic reticulum vesicles, as well as single channel opening probability of the ryanodine receptor/calcium release channels incorporated in bilayers. The possible participation of calsequestrin, or of other luminal proteins of sarcoplasmic reticulum in this regulation is addressed. A comparison with the regulation by luminal calcium of calcium release mediated by the inositol 1,4,5-trisphosphate receptor/calcium channel is presented as well.

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Sarcoplasmic Reticulum Calcium Release Channels in Ventricles of Older Adult Hamsters

Canadian Journal on Aging / La Revue canadienne du vieillissement ◽

10.1353/cja.2006.0026 ◽

2006 ◽

Vol 25 (1) ◽

pp. 107-113 ◽

Cited By ~ 3

Author(s):

Peter A. Nicholl ◽

Susan E. Howlett

Keyword(s):

Sarcoplasmic Reticulum ◽

Older Adult ◽

Binding Sites ◽

Calcium Release ◽

Ryanodine Receptors ◽

Calcium Release Channels ◽

Site Density ◽

Age Related ◽

Sarcoplasmic Reticulum Calcium ◽

Age Related Changes

ABSTRACTWhether the density of sarcoplasmic reticulum (SR) calcium release channels / ryanodine receptors in the heart declines with age is not clear. We investigated age-related changes in the density of «3H»-ryanodine receptors in crude ventricular homogenates, which contained all ligand binding sites in heart and in isolated junctional SR membranes. Experiments utilized young (120 days) and older adult (300 days) hamsters. «3H»-ryanodine binding site density did not change with age in crude homogenate preparations, although total heart protein concentration increased significantly with age. In contrast, the density of «3H»-ryanodine binding sites decreased markedly in heavy SR membranes purified from older hearts. These results show that demonstration of age-related changes in cardiac ryanodine receptor density depends upon the preparation used. Furthermore, the increase in total ventricular protein with age suggests that normalization of data by membrane protein should be used with caution in studies of aging heart.

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