Rate of force development is Ca2+-dependent and influenced by Ca2+-sensitivity in human single muscle fibres from older adults

Mazara, Nicole; Zwambag, Derek P.; Noonan, Alex M.; Weersink, Erin; Brown, Stephen H.M.; Power, Geoffrey A.

doi:10.1016/j.exger.2021.111348

Cited by 18 publications

(29 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Importantly, the vastus intermedius has repeatedly been shown to have strong adaptations to downhill eccentric training in the form of increased serial sarcomere number (Butterfield et al, 1985 ; Hinks et al, 2022 ; Lynn & Morgan, 1994 ). While in the dissecting solution, several muscle fiber bundles of approximately 0.5–1 mm in width and 3 mm in length were dissected and transferred to a tube containing 2.5 ml of chilled skinning solution on ice for 30 min to be chemically permeabilized (Mazara et al, 2021 ). Gentle agitation was performed to ensure that all bundles were constantly submerged in the solution, resulting in equal permeabilization.…”

Section: Methodsmentioning

confidence: 99%

“…The average of the fiber diameters was used to calculate cross‐sectional area (CSA) assuming circularity. To initiate activation, the fibers were transferred to a pre‐activating solution (reduced Ca 2+ buffering capacity with ATP) for 20 s, then to an activating solution (pCa 7.0, 6.6, 6.4, 6.2, 5.7, 5.5, and 4.5) for 30 s (Mashouri et al, 2021 ; Mazara et al, 2021 ). Single fiber optimal force ( P o ) at each pCa level was taken as the highest 500 ms moving average along the force‐time curve during the 30 s window.…”

Section: Methodsmentioning

confidence: 99%

“…After the completion of mechanical testing, the fiber was placed in 15 μl of solubilization buffer containing 61 mM tris (pH 6.8), 11% (v/v) glycerol, 2.78% (w/v) sodium dodecyl sulfate (SDS), 5% 2‐β mercaptoethanol, and 0.02% (w/v) bromophenol blue and stored at −20°C until fiber typing was to begin (Mashouri et al, 2021 ; Mazara et al, 2021 ). The myosin heavy chain (MHC) composition of single fibers was determined by SDS polyacrylamide gel electrophoresis (SDS‐PAGE).…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Influence of 4 weeks of downhill running on calcium sensitivity of rat single muscle fibers

Hubbard

Hinks

Mashouri

et al. 2022

Physiological Reports

Self Cite

View full text Add to dashboard Cite

Improved Ca 2+ sensitivity has been suggested as a mechanism behind enhancements in muscle mechanical function following eccentric training. However, little is known regarding the effects of eccentric training on single muscle fiber Ca 2+ sensitivity. Adult male Sprague–Dawley rats (sacrificial age ~18 weeks; mass = 400.1 ± 34.8 g) were assigned to an eccentric training ( n = 5) or sedentary control group ( n = 6). Eccentric training consisted of 4 weeks of weighted downhill running 3×/week at a 15° decline and 16 m/min for 35 min per day in 5‐min bouts. After sacrifice, vastus intermedius single muscle fibers were dissected, chemically permeabilized, and stored until testing. Fibers ( n = 63) were isolated, and standard Ca 2+ sensitivity, force, rate of force redevelopment ( k tr ), and active instantaneous stiffness tests were performed using [Ca 2+ ] ranging from 7.0 to 4.5. Following all mechanical testing, fiber type was determined using SDS‐PAGE. There was no difference in pCa 50 (i.e., [Ca 2+ ] needed to elicit half of maximal force) between groups or between fiber types. However, when comparing normalized force across pCa values, fibers from the control group produced greater forces than fibers from the trained group at lower Ca 2+ concentrations ( p < 0.05), and this was most evident for Type I fibers ( p = 0.002). Type II fibers produced faster ( p < 0.001) k tr than Type I fibers, but there were no differences in absolute force, normalized force, or other measures of mechanical function between fibers from the trained and control groups. These findings indicate that eccentric training does not appear to improve single muscle fiber Ca 2+ sensitivity.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Influence of 4 weeks of downhill running on calcium sensitivity of rat single muscle fibers

Hubbard

Hinks

Mashouri

et al. 2022

Physiological Reports

Self Cite

View full text Add to dashboard Cite

show abstract

“…Furthermore, abnormalities in calcium handling, such as impaired sarcoplasmic reticulum storage, release, re-uptake, and leakage, as well as impaired calcium saturation and binding, have a negative impact on calcium sensitivity and cross-bridge cycling. 56) Passive mechanical properties are also affected by aging. 47) For example, mechanical properties such as muscle fiber elasticity measured as instantaneous stiffness is higher in older people.…”

Section: Molecular and Cellular Changes Un-derlying Sarcopeniamentioning

confidence: 99%

Rehabilitation of Older Adults with Sarcopenia: From Cell to Functioning

Frontera

2022

PRM

View full text Add to dashboard Cite

“…The knowledge that the mitochondrial and sarcolemmal phospholipids are differentially affected by LC n -3 PUFAs opens the intriguing possibility that other important cellular phospholipid membranes may also display distinct responses to LC n -3 PUFAs. One interesting area worthy of future work is the impact of LC n -3 PUFA ingestion on the sarcoplasmic reticulum and Ca 2+ handling, which is a vitally important aspect of muscle contraction and may be negatively impacted by aging [ 72 ]. While initial evidence suggests that 12 weeks of 5 g/day LC n -3 PUFA intake in healthy older men does not influence aspects of sarcoplasmic reticulum function [ 73 ], changes in sarcoplasmic reticulum or skeletal muscle phospholipid membrane lipid composition in that study were not directly assessed.…”

Section: Optimal Dose and Incorporation Of Lc N-3 Pufamentioning

confidence: 99%

Fish Oil for Healthy Aging: Potential Application to Master Athletes

Murphy

McGlory

2021

Sports Med

View full text Add to dashboard Cite

Master athletes perform high volumes of exercise training yet display lower levels of physical functioning and exercise performance when compared with younger athletes. Several reports in the clinical literature show that long chain n-3 polyunsaturated fatty acid (LC n-3 PUFA) ingestion promotes skeletal muscle anabolism and strength in untrained older persons. There is also evidence that LC n-3 PUFA ingestion improves indices of muscle recovery following damaging exercise in younger persons. These findings suggest that LC n-3 PUFA intake could have an ergogenic effect in master athletes. However, the beneficial effect of LC n-3 PUFA intake on skeletal muscle in response to exercise training in both older and younger persons is inconsistent and, in some cases, generated from low-quality studies or those with a high risk of bias. Other factors such as the choice of placebo and health status of participants also confound interpretation of existing reports. As such, when considered on balance, the available evidence does not indicate that ingestion of LC n-3 PUFAs above current population recommendations (250–500 mg/day; 2 portions of oily fish per week) enhances exercise performance or recovery from exercise training in master athletes. Further work is now needed related to how the dose, duration, and co-ingestion of LC n-3 PUFAs with other nutrients such as amino acids impact the adaptive response to exercise training. This work should also consider how LC n-3 PUFA supplementation may differentially alter the lipid profile of cellular membranes of key regulatory sites such as the sarcolemma, mitochondria, and sarcoplasmic reticulum.

show abstract

Rate of force development is Ca2+-dependent and influenced by Ca2+-sensitivity in human single muscle fibres from older adults

Cited by 18 publications

References 32 publications

Influence of 4 weeks of downhill running on calcium sensitivity of rat single muscle fibers

Influence of 4 weeks of downhill running on calcium sensitivity of rat single muscle fibers

Rehabilitation of Older Adults with Sarcopenia: From Cell to Functioning

Fish Oil for Healthy Aging: Potential Application to Master Athletes

Contact Info

Product

Resources

About