Excitation‐contraction coupling in skeletal muscle fibers injected with the InsP<sub>3</sub>blocker, heparin

Pape, Paul C.; Konishi, Masato; Baylor, Stephen M.; Somlyo, Andrew P.

doi:10.1016/0014-5793(88)81233-x

Cited by 35 publications

(11 citation statements)

References 26 publications

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“…However, in connection with skeletal muscle, controversial results have been reported regarding the ability of heparin to inhibit the InsP3 -i n d u c e d r e l e a s e o f C a t o r t o b l o c k E -C c o u p l i n g [35,36]. We have previously shown that lengthening of muscle fibers beyond 3.70 tm of sarcomere length induced an irreversible increase in [Ca2+]i (> pCa6) [1].…”

Section: Discussionmentioning

confidence: 97%

Inositol 1,4,5-trisphosphate-induced Ca2+ release is regulated by cytosolic Ca2+ in intact skeletal muscle

López

Terzic

1996

Pflugers Arch - Eur J Physiol

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Microinjection of inositol 1,4,5-trisphosphate (InsP3) into intact skeletal muscle fibers isolated from frogs (Rana temporaria) increased resting cytosolic Ca2+ concentration ([Ca2+]i) as measured by double-barreled Ca2+-selective microelectrodes. In contrast, microinjection of inositol 1-phosphate, inositol 1,4-biphosphate, and inositol 1,4,5,6-tetrakisphosphate did not induce changes in [Ca2+]i. Incubation in low-Ca2+ solution, or in the presence of L-type Ca2+ channel blockers did not affect InsP3-induced release of cytosolic Ca2+. Neither ruthenium red, a blocker of ryanodine receptor Ca2+-release channels, nor cytosolic Mg2+, a known inhibitor of the Ca2+-induced Ca2+-release process, modified the InsP3-induced release of cytosolic Ca2+. However, heparin, a blocker of InsP3 receptors, inhibited InsP3-induced release of cytosolic Ca2+. Also, pretreatment with dantrolene or azumulene, two inhibitors of cytosolic Ca2+ release, reduced [Ca2+]i, and prevented InsP3 from inducing release of cytosolic Ca2+. Incubation in caffeine or lengthening of the muscle increased [Ca2+]i and enhanced the ability of InsP3 to induce release of cytosolic Ca2+. These results indicate that InsP3, at physiological concentrations, induces Ca2+ release in intact muscle fibers, and suggest that the InsP3-induced Ca2+ release is regulated by [Ca2+]i. A Ca2+-dependent effect of InsP3 on cytosolic Ca2+ release could be of importance under physiological or pathophysiological conditions associated with alterations in cytosolic Ca2+ homeostasis.

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Section: Discussionmentioning

confidence: 97%

Inositol 1,4,5-trisphosphate-induced Ca2+ release is regulated by cytosolic Ca2+ in intact skeletal muscle

López

Terzic

1996

Pflugers Arch - Eur J Physiol

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“…This compound was first used to block mitochondrial Ca 2+ transport (Moore, 1971). Later it was shown to inhibit Ca 2+ release from the SR of striated and smooth muscles (Ohnishi, 1979;Miyamoto and Racker, 1982;Antoniu, Kim, Morii, and Ikemoto, 1985;Pampe, Konishi, Baylor, and Somlyo, 1988). It is capable of quenching the efflux of 45Ca from the junctional SR vesicles within milliseconds after addition (Ikemoto, Antoniu, and Meszaros, 1985;Meissner, Darling, and Eveleth, 1986;Sumbilla and Inesi, 1987;Calviello and Chiesi, 1989).…”

Section: Introductionmentioning

confidence: 99%

Block by ruthenium red of the ryanodine-activated calcium release channel of skeletal muscle.

1993

The Journal of General Physiology

101

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A B S T R A C T The effects of ruthenium red and the related compounds tetraamine palladium (4APd) and tetraamine platinum (4APt) were studied on the ryanodine activated Ca ~+ release channel reconstituted in planar bilayers with the immunoaffinity purified ryanodine receptor. Ruthenium red, applied at submicromolar concentrations to the myoplasmic side (c/s), induced an all-or-none flickery block of the ryanodine activated channel. The blocking effect was strongly voltage dependent, as large positive potentials that favored the movement of ruthenium red into the channel conduction pore produced stronger block. The half dissociation constants (Kd) for ruthenium red block of the 500 pS channel were 0.22, 0.38, and 0.62 p-M, at +100, +80, and +60 mV, respectively. Multiple ruthenium red molecules seemed to be involved in the inhibition, because a Hill coefficient of close to 2 was obtained from the dose response curve. The half dissociation constant of ruthenium red block of the lower conductance state of the ryanodine activated channel (250 pS) was higher (Kd = 0.82 p-M at + 100 mV), while the Hill coefficient remained approximately the same (nil ----2.7). Ruthenium red block of the channel was highly asymmetric, as tram ruthenium red produced a different blocking effect. The blocking and unblocking events (induced by c/s ruthenium red) can be resolved at the single channel level at a cutoff frequency of 2 kHz. The closing rate of the channel in the presence of ruthenium red increased linearly with ruthenium red concentration, and the unblocking rate of the channel was independent of ruthenium red concentrations. This suggests that ruthenium red block of the channel occurred via a simple blocking mechanism. The on-rate of ruthenium red binding to the channel was 1.32 x 109 M -I s -l, and the off-rate of ruthenium red binding was 0.75 x l0 s s -1 at +60 mV, in the presence of 200 nM ryanodine. The two related compounds, 4APd and 4APt, blocked the channel in a similar way to that of ruthenium red. These compounds inhibited the open channel with lower affinities (Kd = 170 p.M, 4APd; Kd = 656 p-M, 4APt), and had Hill coefficients of close to 1. The results suggest that ruthenium red block of the ryanodine receptor is due to binding to multiple sites located in the conduction pore of the channel.

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“…The effect of extracellular heparin on mammalian muscle is controversial: the ryanodine receptor (RyR) is activated by heparin in vitro (Ritov et al, 1985;Bezprozvanny et al, 1993), and the heparin antagonist protamine reversibly blocks the RyR (Koulen and Ehrlich, 2000). Paradoxically, the structurally similar inositol trisphosphate receptor (InsP3R) is inhibited by heparin (Gosh et al, 1988;Kobayashi et al, 1988), whereas in frog muscle heparin cannot activate RyR nor inhibit InsP3R (Pape et al, 1988;Rojas and Jamovich, 1990). Heparin also affects the kinetic properties of the dihydropyridine receptor (DHPR; Knaus et al, 1990;Martinez et al, 1996): intracellular application blocks excitation-contraction coupling in toad (but not in rat) muscle fibers, an effect likely caused by desensitizing the DHPR voltage sensor (Lamb et al, 1994).…”

Section: Hs In Excitation-contraction Couplingmentioning

confidence: 99%

Heparan sulfates in skeletal muscle development and physiology

Jenniskens

Veerkamp²,

Kuppevelt³

2005

Journal Cellular Physiology

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Recent years have seen an emerging interest in the composition of the skeletal muscle extracellular matrix (ECM) and in the developmental and physiological roles of its constituents. Many cell surface-associated and ECM-embedded molecules occur in highly organized spatiotemporal patterns, suggesting important roles in the development and functioning of skeletal muscle. Glycans are historically underrepresented in the study of skeletal muscle ECM, even though studies from up to 30 years ago have demonstrated specific carbohydrates and glycoproteins to be concentrated in neuromuscular junctions (NMJs). Changes in glycan profile and distribution during myogenesis and synaptogenesis hint at an active involvement of glycoconjugates in muscle development. A modest amount of literature involves glycoconjugates in muscle ion housekeeping, but a recent surge of evidence indicates that glycosylation defects are causal for many congenital (neuro)muscular disorders, rendering glycosylation essential for skeletal muscle integrity. In this review, we focus on a single class of ECM-resident glycans and their emerging roles in muscle development, physiology, and pathology: heparan sulfate proteoglycans (HSPGs), notably their heparan sulfate (HS) moiety.

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Excitation‐contraction coupling in skeletal muscle fibers injected with the InsP₃blocker, heparin

Cited by 35 publications

References 26 publications

Inositol 1,4,5-trisphosphate-induced Ca2+ release is regulated by cytosolic Ca2+ in intact skeletal muscle

Inositol 1,4,5-trisphosphate-induced Ca2+ release is regulated by cytosolic Ca2+ in intact skeletal muscle

Block by ruthenium red of the ryanodine-activated calcium release channel of skeletal muscle.

Heparan sulfates in skeletal muscle development and physiology

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Excitation‐contraction coupling in skeletal muscle fibers injected with the InsP3blocker, heparin

Cited by 35 publications

References 26 publications

Inositol 1,4,5-trisphosphate-induced Ca2+ release is regulated by cytosolic Ca2+ in intact skeletal muscle

Inositol 1,4,5-trisphosphate-induced Ca2+ release is regulated by cytosolic Ca2+ in intact skeletal muscle

Block by ruthenium red of the ryanodine-activated calcium release channel of skeletal muscle.

Heparan sulfates in skeletal muscle development and physiology

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Excitation‐contraction coupling in skeletal muscle fibers injected with the InsP₃blocker, heparin