scholarly journals Calcium pools mobilized by calcium or inositol 1,4,5-trisphosphate are differentially localized in rat heart and brain.

1992 ◽  
Vol 3 (6) ◽  
pp. 621-631 ◽  
Author(s):  
A Verma ◽  
D J Hirsch ◽  
S H Snyder
Keyword(s):  
Binding Sites ◽  
Calcium Release ◽  
Cardiac Tissue ◽  
Coronary Vessels ◽  
Medial Septum ◽  
Ruthenium Red ◽  
Cardiac Conduction ◽  
Inositol 1,4,5 Trisphosphate ◽  
Calcium Induced Calcium Release ◽  
The Brain

Calcium-induced calcium release (CICR) pools have been demonstrated in brain and heart microsomes biochemically and autoradiographically by the sensitivity of 45Ca2+ accumulation to Mg2+, ATP, ruthenium red, caffeine, and tetracaine. The CICR pool colocalizes with [3H]ryanodine binding sites, supporting the notion that [3H]ryanodine labels CICR pools. Sites of CICR pools in the brain contrast with those of inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ pools with reciprocal localizations between the two Ca2+ pools in several structures. Thus, in the hippocampus CA-1 is enriched in IP3-sensitive Ca2+ pools, whereas CICR pools are highest in CA-3 and the dentate gyrus. The corpus striatum and cerebellum are enriched in IP3 pools, whereas the medial septum and olfactory bulb have high CICR densities. In cardiac tissue, CICR is localized to atrial and ventricular muscle, whereas IP3 pools are concentrated in coronary vessels and cardiac conduction fibers. The reciprocal enrichment of IP3 and CICR Ca2+ pools implies differential regulation of Ca2+ hemostasis in these tissues.

Endotoxin Alteration of the Mucopolysaccharide Blood Vessel Coating in Rats

1974 ◽  
Vol 32 ◽  
pp. 148-149
Author(s):  
D. E. Philpott ◽  
A. Takahashi
Keyword(s):  
Skeletal Muscle ◽  
Endothelial Cells ◽  
Salivary Gland ◽  
Carotid Artery ◽  
Basement Membrane ◽  
Coronary Vessels ◽  
Ruthenium Red ◽  
E Coli ◽  
Old Rats ◽  
The Brain

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.

scholarly journals Sphingosylphosphocholine modulates the ryanodine receptor/calcium-release channel of cardiac sarcoplasmic reticulum membranes

1997 ◽  
Vol 322 (1) ◽  
pp. 327-333 ◽  
Author(s):  
Romeo BETTO ◽  
Alessandra TERESI ◽  
Federica TURCATO ◽  
Giovanni SALVIATI ◽  
Roger A. SABBADINI ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Ryanodine Receptor ◽  
Calcium Release ◽  
Cardiac Tissue ◽  
Ruthenium Red ◽  
Release Mechanism ◽  
Calcium Release Channel ◽  
Release Channel ◽  
Cardiac Sarcoplasmic Reticulum ◽  
High Calcium

Sphingosylphosphocholine (SPC) modulates Ca2+ release from isolated cardiac sarcoplasmic reticulum membranes; 50 ƁM SPC induces the release of 70Ő80% of the accumulated calcium. SPC releases calcium from cardiac sarcoplasmic reticulum through the ryanodine receptor, since the release is inhibited by the ryanodine receptor channel antagonists ryanodine, Ruthenium Red and sphingosine. In intact cardiac myocytes, even in the absence of extracellular calcium, SPC causes a rise in diastolic Ca2+, which is greatly reduced when the sarcoplasmic reticulum is depleted of Ca2+ by prior thapsigargin treatment. SPC action on the ryanodine receptor is Ca2+-dependent. SPC shifts to the left the Ca2+-dependence of [3H]ryanodine binding, but only at high pCa values, suggesting that SPC might increase the sensitivity to calcium of the Ca2+-induced Ca2+-release mechanism. At high calcium concentrations (pCa 4.0 or lower), where [3H]ryanodine binding is maximally stimulated, no effect of SPC is observed. We conclude that SPC releases calcium from cardiac sarcoplasmic reticulum membranes by activating the ryanodine receptor and possibly another intracellular Ca2+-release channel, the sphingolipid Ca2+-release-mediating protein of endoplasmic reticulum (SCaMPER) [Mao, Kim, Almenoff, Rudner, Kearney and Kindman (1996) Proc. Natl. Acad. Sci. U.S.A 93, 1993Ő1996], which we have identified for the first time in cardiac tissue.

Ruthenium red selectively prevents Ins(1,4,5)P3-but not caffeine-gated calcium release in avian atrium

1992 ◽  
Vol 262 (1) ◽  
pp. H268-H277 ◽  
Author(s):  
A. M. Vites ◽  
A. J. Pappano
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Calcium Release ◽  
Present Report ◽  
Ruthenium Red ◽  
Detectable Effect ◽  
Calcium Accumulation ◽  
Two Agents ◽  
Release Mechanisms ◽  
Subsequent Response ◽  
Inositol 1,4,5 Trisphosphate

We previously reported that inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and caffeine evoked contractures in saponin-permeabilized chick atria. The magnitude of contractures evoked by maximally effective concentrations of Ins(1,4,5)P3 were half those evoked by maximally effective concentrations of caffeine. In the present report, we tested the hypothesis that these two agents may act on distinct calcium-release mechanisms by comparing the effects of ryanodine, ruthenium red, and procaine on the responses to Ins(1,4,5)P3 and caffeine. We find that procaine inhibits both responses with similar mean inhibitory concentrations in the millimolar range. Nanomolar concentrations of ryanodine selectively potentiate the contractures induced by Ins(1,4,5)P3 but have no effect on those induced by caffeine. Micromolar concentrations of ryanodine inhibit responses to both Ins(1,4,5)P3 and caffeine in a use-dependent way. Ruthenium red prevents the response to Ins(1,4,5)P3 and potentiates that to caffeine, as if ruthenium red had enhanced calcium accumulation in the caffeine-sensitive pool(s). Because we found that caffeine prevented the subsequent response to Ins(1,4,5)P3, but Ins(1,4,5)P3 had no detectable effect on the caffeine-induced contracture, we conclude that Ins(1,4,5)P3 and caffeine act on pharmacologically distinct calcium-release mechanisms that may reside in the same sarcoplasmic reticulum compartment.

scholarly journals Activation of Ca(2+)-dependent currents in cultured rat dorsal root ganglion neurones by a sperm factor and cyclic ADP-ribose.

1992 ◽  
Vol 3 (12) ◽  
pp. 1415-1425 ◽  
Author(s):  
K P Currie ◽  
K Swann ◽  
A Galione ◽  
R H Scott
Keyword(s):  
Dorsal Root Ganglion ◽  
Dorsal Root ◽  
Calcium Release ◽  
Ruthenium Red ◽  
Buffering Capacity ◽  
Mammalian Sperm ◽  
Cyclic Adp Ribose ◽  
Sperm Factor ◽  
Calcium Induced Calcium Release ◽  
Mammalian Eggs

The effects of intracellular application of two novel Ca2+ releasing agents have been studied in cultured rat dorsal root ganglion (DRG) neurones by monitoring Ca(2+)-dependent currents as a physiological index of raised free cytosolic Ca2+ ([Ca2+]i). A protein based sperm factor (SF) extracted from mammalian sperm, has been found to trigger Ca2+ oscillations and to sensitize unfertilized mammalian eggs to calcium induced calcium release (CICR). In this study intracellular application of SF activated Ca(2+)-dependent currents in approximately two-thirds of DRG neurones. The SF induced activity was abolished by heat treatment, attenuated by increasing the intracellular Ca2+ buffering capacity of the cells and persisted when extracellular Ca2+ was replaced by Ba2+. In addition, activity could be triggered or potentiated by loading the cells with Ca2+ by activating a series of voltage-gated Ca2+ currents. Ca(2+)-activated inward current activity was also generated by intracellular application of cyclic ADP-ribose (cADPR), a metabolite of NAD+, which causes Ca2+ release in sea urchin eggs. This activity could also be enhanced by loading the cells with Ca2+. The cADPR induced activity, but not the SF induced activity, was abolished by depleting the caffeine sensitive Ca2+ store. Ruthenium red markedly attenuated SF induced activity but had little action on cADPR induced activity or caffeine induced activity. Our results indicate that both SF and cADPR release intracellular Ca2+ pools in DRG neurones and that they appear to act on subtly distinct stores or distinct intracellular Ca2+ release mechanisms, possibly by modulating CICR.

Interaction of ryanodine with the calcium releasing system of sarcoplasmic reticulum vesicles

1988 ◽  
Vol 43 (1-2) ◽  
pp. 140-148 ◽  
Author(s):  
Wilhelm Hasselbach ◽  
Andrea Migala
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Binding Sites ◽  
Time Course ◽  
Calcium Release ◽  
Reaction Times ◽  
Titration Curves ◽  
Equilibrium Data ◽  
Number Of Binding Sites ◽  
Reported Data ◽  
Calcium Induced Calcium Release

Heavy sarcoplasmic reticulum vesicles were reacted with ryanodine in 0.6 ᴍKCl 0.3 ᴍ sucrose at pH 6.3 and pH 7.0 at 20 °C. The inhibition of caffeine induced calcium release from actively loaded vesicles by ryanodine was applied to monitor time course and attainment of equilibrium of the interaction of ryanodine with its receptors in the vesicular membranes. At ryanodine concentrations rising from 0.1-100 μᴍ, the logarithms of the release amplitudes linearly decline with time. The dependence of the inactivation reaction on the concentration of ryanodine did not saturate in the applicable concentration range. The reaction halflife times are concentration dependent. At pH 7.0, the half times decline from 100 to 10 s when the ryanodine concentration is raised from 0.1 to 1 μᴍ. At pH 6.3 a corresponding decline occurs between 3 μᴍ and 100 μᴍ. The marked dependence of the inactivation reaction on medium pH requires reaction times of one and five hours at pH 7.0 and 6.3, respectively for the attainment of reaction equilibrium at low ryanodine concentrations. The dependence of the amplitude of calcium release on the concentration of added ryanodine has been evaluated as proposed by Gutfreund (Enzymes: Physical Principles, p. 71, Wiley-Interscience, London 1972) for the preparation’s affinity for ryanodine and its number of binding sites. At pH 7.0, preparations appear to contain only 0.7 pmol sites per mg protein having an affinity for ryanodine of 0.33 nᴍ-1. The titration curves for caffeine induced calcium release, initial calcium uptake and final calcium level are identical, indicating that the three functions are controlled by the same receptor. Calcium induced calcium release, however, is only partially and differently affected by the occupancy of the high affinity ryanodine binding sites. The kinetic and equilibrium data for the effects of ryanodine were combined and analyzed on account of a two step reaction sequence. The corresponding dissociation and rate constants were evaluated and combined with reported data of [3H]ryanodine binding (Pessah et al., J. Biol. Chem. 261, 8643-8648 (1986))

Immunoelectron microscope detection of C-type natriuretic peptide in normal human atrial tissue

1993 ◽  
Vol 51 ◽  
pp. 388-389
Author(s):  
Chi-Ming Wei ◽  
Margaret Hukee ◽  
Christopher G.A. McGregor ◽  
John C. Burnett
Keyword(s):  
Amino Acid ◽  
Natriuretic Peptide ◽  
Vascular Tone ◽  
Cardiac Tissue ◽  
Ring Structure ◽  
Terminal Amino Acid ◽  
Amino Acid Peptide ◽  
Normal Human ◽  
Terminal Amino ◽  
The Brain

C-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial (ANP) and brain natriuretic peptide (BNP). CNP exists as a 22-amino acid peptide and like ANP and BNP has a 17-amino acid ring formed by a disulfide bond. Unlike these two previously identified cardiac peptides, CNP lacks the COOH-terminal amino acid extension from the ring structure. ANP, BNP and CNP decrease cardiac preload, but unlike ANP and BNP, CNP is not natriuretic. While ANP and BNP have been localized to the heart, recent investigations have failed to detect CNP mRNA in the myocardium although small concentrations of CNP are detectable in the porcine myocardium. While originally localized to the brain, recent investigations have localized CNP to endothelial cells consistent with a paracrine role for CNP in the control of vascular tone. While CNP has been detected in cardiac tissue by radioimmunoassay, no studies have demonstrated CNP localization in normal human heart by immunoelectron microscopy.

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