Sequential effects of GSNO and H₂O₂ on the Ca²⁺ sensitivity of the contractile apparatus of fast- and slow-twitch skeletal muscle fibers from the rat

Abstract

Spencer T, Posterino GS. Sequential effects of GSNO and H2O2 on the Ca 2ϩ sensitivity of the contractile apparatus of fast-and slow-twitch skeletal muscle fibers from the rat. Am J Physiol Cell Physiol 296: C1015-C1023, 2009. First published February 18, 2009 doi:10.1152/ajpcell.00251.2008.-Reactive oxygen species (ROS), such as hydrogen peroxide (H2O2) and nitric oxide (NO), have been shown to differentially alter the Ca 2ϩ sensitivity of the contractile apparatus of fast-twitch skeletal muscle, leading to the proposal that normal muscle function is controlled by perturbations in the amounts of these two groups of molecules (28). However, no previous studies have examined whether these opposing actions are retained when the contractile apparatus is subjected to both molecule types. Using mechanically skinned fast-and slow-twitch skeletal muscle fibers of the rat, we compared the effects of sequential addition of nitrosoglutathione (GSNO), a NO donor, and H2O2 on the Ca 2ϩ sensitivity of the contractile apparatus. As expected from previous reports in fast-twitch fibers, when added separately, GSNO (1 mM) reduced the Ca 2ϩ sensitivity of the contractile apparatus, whereas H2O2 (10 mM; added during contractions) increased the Ca 2ϩ sensitivity of the contractile apparatus. When added sequentially to the same fiber, such that the oxidation by one molecule (e.g., GSNO) preceded the oxidation by the other (e.g., H2O2), and vice versa, the individual effects of both molecules on the Ca 2ϩ sensitivity were retained. Interestingly, neither molecule had any effect on the Ca 2ϩ sensitivity of slow-twitch skeletal muscle. The data show that H 2O2 and GSNO retain the capacity to independently affect the contractile apparatus to modulate force. Furthermore, the absence of effects in slow-twitch muscle may further explain why this fiber type is relatively insensitive to fatigue. nitric oxide; reactive oxygen species; nitrosoglutathione; hydrogen peroxide THE REDOX STATE OF A SKELETAL muscle cell has been hypothesized to affect the force output in a similar fashion to other homeostatic variables such as pH and temperature (28). Skeletal muscle is known to produce a number of reactive oxygen species (termed ROS) as well as a variety of nitrogen-based compounds that include nitric oxide (NO) (see review in Ref. 29) that contribute to the redox state of the cell. The production of both ROS and NO occurs at varying rates during both rest and activity (29) as a by-product of oxidative metabolism (5). Reid et al. (28) had proposed a model depicting a biphasic effect of changes in cellular redox state on isometric force. The model predicted that basal (resting) levels of ROS (and/or NO) in muscle normally maintain a suboptimal performance level that can be modified by activity that results in deviations in contractile force output both potentially increasing and decreasing force. To date, there have been a number of studies in both intact muscle and skinned muscle fibers examining the effects of both ROS and NO on contractile a...

ROS-Mediated Decline in Maximum Ca2+-Activated Force in Rat Skeletal Muscle Fibers following In Vitro and In Vivo Stimulation

“…For example, in rat skinned SOL and EDL fibers H 2 O 2 is relatively ineffective, with a 5 min exposure to 10 mM H 2 O 2 causing only a small decrease in the Hill coefficient with little or no effect of F max [12] (similar to findings in diaphragm [11]), whereas OH • causes concomitant decrease in both Ca 2+ -sensitivity and F max [13]. Nitric oxide (NO • ) donors, GSNO or SNAP, on the other hand, cause substantial Ca 2+ -sensitivity changes in fast-twitch (EDL) fibers but have little effect on F max except at very high concentration [17], [19]. In contrast to the above oxidants, peroxynitrite causes a marked decrease in F max in skinned SOL fibers with little change in Ca 2+ -sensitivity, and has relatively less effect in EDL fibers [18], strikingly like that found here in the stimulated fibers (Figs.…”

“…Application of exogenous ROS and RNS have been shown to have various effects on maximum force production and/or Ca 2+ sensitivity of the myofilaments [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], as well as on the activity of the sarcoplasmic reticulum (SR) Ca 2+ pumps (SERCA) [20], and the SR Ca 2+ release channels (ryanodine receptors) [21], [22] (for review see [23], [24], [25]). ROS and RNS are generated in muscle with both hypoxia and hyperoxia [26], [27], as well as with elevated muscle temperature in vitro [28], [29].…”

“…Application of superoxide also causes a decrease in F max in diaphragm fibers, though its effects on Ca 2+ -sensitivity were not ascertained [11]. In contrast, related ROS and RNS, including H 2 O 2 , hydroxyl, NO and GSNO, have quite different actions on limb muscle fibers, changing Ca 2+ -sensitivity more readily than F max or having little if any effect (as in case of H 2 O 2 ) [12], [13], [17], [19].…”

Oxygen Consumption and Usage During Physical Exercise: The Balance Between Oxidative Stress and ROS-Dependent Adaptive Signaling

“…In the skeletal muscle, the differences in antioxidant and DNA repair capacity between slow-and fast-twitch fibers are strongly dependent on metabolism and ROS production capacity (152,268,313,370). The exercise-associated ROS dependence of epigenetics is still not well studied, but the available limited data suggest that regular exercise could alter DNA methylation and the post-translational modification of histone residues by redox-mediated adaptation.…”

EMD 57033 partially reverses ventilator-induced diaphragm muscle fibre calcium desensitisation

“…Since specific force as well as Ca 2+ activation are contractile parameters notably dependent on the proteins content, i.e. myosin [26] and thin filament proteins [23], and on their oxidation status [14,36], the first aim of the present study was to test the hypothesis that Ca 2+ sensitivity of contraction is disrupted in VIDD. The skinned fibre preparation has therefore been used to compare contractile function in single diaphragm muscle fibres from sham-operated control piglets and from piglets mechanically ventilated for 5 days.…”