Potentiation of sarcoplasmic reticulum Ca2+ release by 2,3-butanedione monoxime in crustacean muscle

1993 ◽  
Vol 424 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Sandor Gy�rke ◽  
Christine Dettbarn ◽  
Philip Palade
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Crustacean Muscle ◽  
Butanedione Monoxime

scholarly journals Energy expenditure by Ba2+contracture in rat ventricular slices derives from cross-bridge cycling

1999 ◽  
Vol 277 (1) ◽  
pp. H74-H79 ◽  
Author(s):  
Hisaharu Kohzuki ◽  
Hiromi Misawa ◽  
Susumu Sakata ◽  
Yoshimi Ohga ◽  
Hiroyuki Suga ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Energy Expenditure ◽  
Cyclopiazonic Acid ◽  
Left Ventricular ◽  
Basal Metabolism ◽  
Dependent Manner ◽  
Tyrode Solution ◽  
Cross Bridge ◽  
Butanedione Monoxime ◽  
Dose Dependent

To clarify the energy-expenditure mechanism during Ba2+ contracture of mechanically unloaded rat left ventricular (LV) slices, we measured myocardial O2 consumption (V˙o 2) of quiescent slices in Ca2+-free Tyrode solution andV˙o 2 during Ba2+ contracture by substituting Ca2+ with Ba2+. We then investigated the effects of cyclopiazonic acid (CPA) and 2,3-butanedione monoxime (BDM) on the Ba2+ contractureV˙o 2. The Ca2+-freeV˙o 2 corresponds to that of basal metabolism (2.32 ± 0.53 ml O2 ⋅ min−1 ⋅ 100 g LV−1). Ba2+ increased theV˙o 2 in a dose-dependent manner (from 0.3 to 3.0 mmol/l) from 110 to 150% of basal metabolic V˙o 2. Blockade of the sarcoplasmic reticulum (SR) Ca2+ pump by CPA (10 μmol/l) did not at all decrease the Ba2+-activatedV˙o 2. BDM (5 mmol/l), which specifically inhibits cross-bridge cycling, reduced the Ba2+activatedV˙o 2 almost to basal metabolic V˙o 2. These energetic results revealed that the Ba2+-activatedV˙o 2 was used for the cross-bridge cycling but not for the Ca2+ handling by the SR Ca2+ pump.

Effects of isoflurane on [Ca2+]i, SR Ca2+ content, and twitch force in intact trabeculae

1998 ◽  
Vol 275 (4) ◽  
pp. H1360-H1369 ◽  
Author(s):  
Yandong Jiang ◽  
Fred J. Julian
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Depressant Effect ◽  
Rapid Cooling ◽  
Twitch Force ◽  
Isoflurane Concentration ◽  
Contractile System ◽  
Intracellular Ca ◽  
Butanedione Monoxime ◽  
Versus Peak ◽  
Ventricular Trabeculae

The goal was to test whether isoflurane exerts its depressant effect on the heart by mainly affecting the intracellular Ca2+ transient [Ca2+]i. Intact rat ventricular trabeculae, paced at 0.5 Hz and 30°C with extracellular [Ca2+] ([Ca2+]o) of 2 mM, were used. The [Ca2+]iwas monitored using fura 2 injected into the myoplasm. The sarcoplasmic reticulum (SR) Ca2+ content was estimated using rapid cooling with or without caffeine to induce Ca2+ release and contracture. A plot of peak twitch force versus peak [Ca2+]itransient with increasing isoflurane concentration declines linearly so that a 56% reduction in the peak [Ca2+]itransient would abolish twitch force. This relationship is intermediate between those obtained with lowering [Ca2+]o, which depresses twitch force through a reduction of the [Ca2+]itransient, and adding 2,3-butanedione monoxime, which reduces the responsiveness of the contractile system to [Ca2+]i. The isoflurane effect is different from that of halothane with respect to both the above relationship and the rapid-cooling response. Isoflurane abolishes the ability of rapid cooling to liberate Ca2+ from the SR.

Effects of 2,3-butanedione monoxime on sarcoplasmic reticulum of saponin-treated rat cardiac muscle

1993 ◽  
Vol 265 (5) ◽  
pp. H1493-H1500 ◽  
Author(s):  
D. S. Steele ◽  
G. L. Smith
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Cardiac Muscle ◽  
Adenine Nucleotides ◽  
Direct Action ◽  
Negative Inotropic Effect ◽  
Inotropic Effect ◽  
Butanedione Monoxime ◽  
Net Release

We have studied the effects of 2,3-butanedione monoxime (BDM) on the sarcoplasmic reticulum (SR) of saponin-treated rat cardiac trabeculae. Rapid application of 20 mM caffeine released Ca2+ from the SR, which was detected using the fluorescent Ca2+ indicator indo 1. The amplitude of the caffeine-induced Ca2+ transient was used as an index of the Ca2+ content of the SR before, during, and after exposure to various concentrations of BDM. BDM (1-5 mM) had little effect on caffeine-induced Ca2+ release. At these levels of BDM, force was inhibited predominantly by a direct action of BDM on the myofilaments. However, with higher concentrations (5-30 mM), BDM caused a concentration-dependent decrease in the amount of Ca2+ released from the SR in response to caffeine. This action of BDM may contribute to the negative inotropic effect of the drug in intact cardiac preparations by reducing the amount of Ca2+ available for release during systole. Rapid application of BDM induced a net release of Ca2+ from the SR. Both BDM and caffeine-induced Ca2+ releases were abolished following treatment of the muscle with 10 microM ryanodine. BDM failed to release Ca2+ in the absence of ATP or after substitution of ATP with nonhydrolyzable adenine nucleotides. In contrast, caffeine released Ca2+ in the absence of ATP. The possible involvement of the Ca(2+)-uptake pump in the action of BDM on the SR is discussed.

scholarly journals Caffeine and micromolar Ca2+ concentrations can release Ca2+ from ryanodine-sensitive stores in crab and lobster striated muscle fibres

1996 ◽  
Vol 199 (11) ◽  
pp. 2419-2428 ◽  
Author(s):  
T Lea
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Cardiac Muscle ◽  
Striated Muscle ◽  
Abdominal Muscle ◽  
Isometric Tension ◽  
Muscle Fibres ◽  
Phasic Contraction ◽  
Crustacean Muscle ◽  
Time Integral ◽  
Variable Nature

Ca2+ release mechanisms were studied in striated muscle from the walking legs of crabs using isometric tension recordings from isolated myofibrillar bundles. Caffeine-induced phasic contractions had properties consistent with Ca2+ release from a sarcoplasmic store, which could be optimally loaded in the presence of ATP at pCa 6.4­6.1. Ryanodine (10 µmol l-1) abolished the caffeine-induced contractions and in solutions with low Ca2+ buffering (0.1 mmol l-1 EGTA) itself caused phasic contractions, indicative of Ca2+ release. Ca2+-induced Ca2+ release (CICR) was observed in a pCa 5.8 solution (buffered by 1 mmol l-1 EGTA) as a phasic contraction of variable nature, inhibited by ryanodine (10 µmol l-1), procaine (10 mmol l-1) or benzocaine (5 mmol l-1). Ca2+ release was measured as a function of releasing pCa by using the force­time integral of the caffeine-induced contraction as an estimate of the Ca2+ remaining in the store. After the Ca2+ store had been loaded for 2 min at pCa 6.6, CICR was measured in the presence of 1 mmol l-1 Mg2+, 1 mmol l-1 EGTA and 5 mmol l-1 ATP. The threshold pCa for CICR was 6.0­6.4 under these conditions and more than 90 % of stored Ca2+ was released in 1 min by pCa values in the range 3.5­5.3. Benzocaine totally inhibited the release and promoted extra Ca2+ loading. Preliminary experiments showed a similar caffeine-releasable store in lobster abdominal muscle, which was slightly less sensitive to free [Ca2+]. It is concluded that in crustacean muscle caffeine and micromolar [Ca2+] can release Ca2+ from a ryanodine-sensitive store, which in many respects is similar to the sarcoplasmic reticulum of vertebrate skeletal and cardiac muscle.

scholarly journals LOCALIZATION AND PROPERTIES OF THE CHOLINESTERASE IN CRUSTACEAN MUSCLE

1973 ◽  
Vol 59 (2) ◽  
pp. 407-420 ◽  
Author(s):  
Neil I. Spielholz ◽  
William G. Van der Kloot
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Blood Cells ◽  
Substrate Inhibition ◽  
Frozen Sections ◽  
Flexor Muscle ◽  
Muscle Enzyme ◽  
Crustacean Muscle ◽  
Dense Deposits ◽  
Whole Muscle ◽  
Kinetics Of

Cholinesterase (ChE) activity is present in crustacean muscle extracts. However, since acetylcholine (ACh) is not a neuromuscular transmitter in these animals, the role and exact localization of ChE was unknown. The histochemical localization of the enzyme was studied in whole muscle and in the sarcoplasmic reticulum fraction of the extract, 50-µm frozen sections of glutaraldehyde-fixed crayfish tail flexor muscle were incubated with acetylthiocholine (ATC) as substrate, and examined under the electron microscope. After some modifications in published techniques, dense deposits were found associated with the sarcolemma, sarcolemmal invaginations, and transverse tubules. No deposits were found in 10-4 M eserine, or if butyrylthiocholine (BTC) was substituted for ATC. The vesicles in the sarcoplasmic reticulum fraction which demonstrate the activity must represent minced bits of these membranes. Using a spectrophotometric method, the kinetics of the crustacean muscle enzyme was compared to the acetylcholinesterase (AChE) on mammalian red blood cells and in the lobster ventral nerve cord. Surprisingly, and contrary to previous reports, the crustacean muscle enzyme did not demonstrate substrate inhibition. While a number of similarities to AChE were found, this lack of substrate inhibition makes questionable an unequivocal similarity with classical AChE.

Effects of the Ca2+ sensitizer EMD 57033 on intracellular Ca2+ in rat ventricular myocytes: relevance to arrhythmogenesis during positive inotropy

2000 ◽  
Vol 99 (6) ◽  
pp. 547-554 ◽  
Author(s):  
Makoto KAWAI ◽  
John A. LEE ◽  
Clive H. ORCHARD
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Rise Time ◽  
Time Course ◽  
Ventricular Myocytes ◽  
Troponin C ◽  
Intact Cells ◽  
Positive Inotropy ◽  
Rat Ventricular Myocytes ◽  
Cross Bridge ◽  
Butanedione Monoxime

We have investigated the effects of the calcium-sensitizing inotropic agent EMD 57033 on Ca2+ handling in intact and skinned rat ventricular myocytes. Intracellular Ca2+ was monitored using fura 2. Myocytes were saponin-skinned, allowing study of sarcoplasmic reticulum (SR) function. In intact myocytes EMD 57033 (1–10 µmol/l) produced a concentration-dependent decrease in the amplitude of the Ca2+ transient and prolonged its declining phase, but had no effect on the rise time. In skinned myocytes, the amplitude of spontaneous Ca2+ release from the SR was decreased by EMD 57033 (5 and 10 µmol/l), although this agent had no significant effect on the frequency of spontaneous Ca2+ release. In the presence of the cross-bridge inhibitor 2,3-butanedione monoxime (5 mmol/l), or in a low bathing Ca2+ concentration (1 mmol/l), EMD 57033 (10 µmol/l) had smaller effects on both the amplitude and time course of the Ca2+ transient in intact cells than in the absence of 2,3-butanedione monoxime or in the presence of 2 and 5 mmol/l Ca2+ respectively. These data suggest that the effects of EMD 57033 on Ca2+ are due to changes in Ca2+ binding to troponin C, secondary to cross-bridge formation. Thus, during positive inotropy, EMD 57033 is unlikely to provoke arrhythmias due to effects on SR Ca2+ handling. In intact cells, its effects on Ca2+ handling would be expected to protect against arrhythmias.

scholarly journals Biochemical Studies on the Sarcoplasmic Reticulum of Fish and Crustacean Muscle.

1996 ◽  
Vol 62 (4) ◽  
pp. 559-561
Author(s):  
Hideki Ushio
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Crustacean Muscle ◽  
Biochemical Studies

Inositol 1,4,5-trisphosphate-induced Ca2+ release from the sarcoplasmic reticulum and contraction in crustacean muscle

1987 ◽  
Vol 65 (4) ◽  
pp. 672-680 ◽  
Author(s):  
Eduardo Rojas ◽  
Verónica Nassar-Gentina ◽  
Mario Luxoro ◽  
Michael E. Pollard ◽  
M. Angélica Carrasco
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Time Course ◽  
Muscle Fibers ◽  
High Dose ◽  
Fixed Amount ◽  
Peak Tension ◽  
Crustacean Muscle ◽  
Period 2 ◽  
Inositol 1,4,5 Trisphosphate ◽  
Phosphatidylinositol 4

Intracellular applications of a fixed amount (0.2 to 8 nmol) of inositol 1,4,5-trisphosphate (InsP3) over a brief period (2 s) into barnacle muscle fibers induced vigorous contractures. Peak tension attained during the first application depended on [InsP3]; the maximum tension evoked by the injection of 8 nmol was 1.6 kg/cm2. Peak tension during a second application of a high dose of InsP3 (> 10 μM) was always smaller than that during the first application. Extracellular Ca2+ could be omitted with no measurable effects on either the amplitude or time course of the contractures evoked by InsP3. Aequorin was used to measure InsP3-evoked Ca2+ release from intracellular stores in minced muscle fibers from lobster and in skinned muscle fibers from barnacle. Provided the sarcoplasmic reticulum was preloaded with Ca2+, application of InsP3 induced a transient Ca2+ release that was [InsP3] dependent. During each transient, [Ca2+] rose rapidly to a peak value (t1/2 < 5 s) and then slowly returned (t1/2 < 100 s) to a basal level. Maximum Ca2+ release was obtained at [InsP3] < 100 μM and amounted to 4 nmol Ca2+/g of muscle, enough to increase [Ca2+]i from 0.1 to 8 μM had the Ca2+ release occurred in the intact fiber. Successive applications of a fixed amount of InsP3 elicited successive transient increases in Ca2+. The effects of [Ca2+] on the incorporation of [3H]inositol into the pools of phosphatidylinositol, phosphatidylinositol 4-phosphate, and phosphatidylinositol 4,5-bisphosphate pools were measured. At 1 μM [Ca2+] the levels of the labelled phosphoinositides increased from 0.98, 0.40, and 0.17 pmol/μmol phosphorus (measured at 0.1 μM) to 1.63, 0.54, and 0.46 pmol/μmol lipid phosphorus, for phosphatidylinositol, phosphatidylinositol 4-phosphate, and phosphatidylinositol 4,5-biphosphate, respectively. These data support the hypothesis that InsP3 could be an intracellular messenger, presumably between the site of Ca2+ entry at the level of the transverse tubular membrane and the sarcoplasmic reticulum membrane, which causes Ca2+ release from Ca2+-loaded sarcoplasmic reticulum in crustacean muscle.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Sign in / Sign up

Export Citation Format

Share Document