Pharmacological block of chloride channels of developing rat skeletal muscle affects the differentiation of specific contractile properties

Stability of rat skeletal muscle contractile properties with time in vitro as a function of incubation temperature was characterized. Female Sprague-Dawley rats (8 wk, 148 g) were anesthetized with pentobarbital sodium (40 mg/kg, ip). Intact soleus (SOL) and extensor digitorum longus (EDL) muscles of 70- to 90-mg mass were removed and studied at incubation temperatures of 20, 25, 30, 35, and 40 degrees C. The average muscle thickness was 2.0 mm. Each muscle was studied at one temperature only. At 5, 15, 30, 45, and 60 min following immersion in an oxygenated Krebs-Ringer bicarbonate solution, isometric contractile properties were measured. Peak twitch tension, maximum tetanic tension, and rate of tension development of both SOL and EDL muscles were stable with time at 20 and 25 degrees C but decreased with time as a function of bath temperature above 25 degrees C. The calculated critical radius for O2 diffusion declined from 1.19 mm at 20 degrees C to 0.51 mm at 40 degrees C. For SOL and EDL muscles incubated at 25 degrees C, the histochemical demonstration of glycogen content was similar to that of fresh muscles, whereas muscles incubated at 40 degrees C showed staining for glycogen only in peripheral fibers. Observed and calculated results both infer a progressively larger hypoxic core at incubation temperatures above 25 degrees C.

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Voltage-dependent gating mechanism for single fast chloride channels from rat skeletal muscle.

The Journal of Physiology ◽

10.1113/jphysiol.1992.sp019229 ◽

1992 ◽

Vol 453 (1) ◽

pp. 279-306 ◽

Cited By ~ 16

Author(s):

D S Weiss ◽

K L Magleby

Keyword(s):

Skeletal Muscle ◽

Chloride Channels ◽

Rat Skeletal Muscle ◽

Gating Mechanism ◽

Voltage Dependent

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Stilbene derivatives inhibit the activity of the inner mitochondrial membrane chloride channels

Cellular & Molecular Biology Letters ◽

10.2478/s11658-007-0019-9 ◽

2007 ◽

Vol 12 (4) ◽

Cited By ~ 10

Author(s):

Izabela Koszela-Piotrowska ◽

Katarzyna Choma ◽

Piotr Bednarczyk ◽

Krzysztof Dołowy ◽

Adam Szewczyk ◽

...

Keyword(s):

Skeletal Muscle ◽

Chloride Channel ◽

Chloride Channels ◽

Mitochondrial Membrane ◽

Disulfonic Acid ◽

Mitochondrial Membranes ◽

Rat Skeletal Muscle ◽

Inner Mitochondrial Membrane ◽

Stilbene Derivatives ◽

Rat Heart Mitochondria

AbstractIon channels selective for chloride ions are present in all biological membranes, where they regulate the cell volume or membrane potential. Various chloride channels from mitochondrial membranes have been described in recent years. The aim of our study was to characterize the effect of stilbene derivatives on single-chloride channel activity in the inner mitochondrial membrane. The measurements were performed after the reconstitution into a planar lipid bilayer of the inner mitochondrial membranes from rat skeletal muscle (SMM), rat brain (BM) and heart (HM) mitochondria. After incorporation in a symmetric 450/450 mM KCl solution (cis/trans), the chloride channels were recorded with a mean conductance of 155 ± 5 pS (rat skeletal muscle) and 120 ± 16 pS (rat brain). The conductances of the chloride channels from the rat heart mitochondria in 250/50 mM KCl (cis/trans) gradient solutions were within the 70–130 pS range. The chloride channels were inhibited by these two stilbene derivatives: 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) and 4-acetamido-4′-isothiocyanostilbene-2,2′-disulfonic acid (SITS). The skeletal muscle mitochondrial chloride channel was blocked after the addition of 1 mM DIDS or SITS, whereas the brain mitochondrial channel was blocked by 300 μM DIDS or SITS. The chloride channel from the rat heart mitochondria was inhibited by 50–100 μM DIDS. The inhibitory effect of DIDS was irreversible. Our results confirm the presence of chloride channels sensitive to stilbene derivatives in the inner mitochondrial membrane from rat skeletal muscle, brain and heart cells.

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