ArticleActa physiologica (Oxford, England)2025
Skeletal Muscle Fatigue in Rats Is More Consistently Related to Increased Inorganic Phosphate Concentration Than Acidosis.
Article in Acta physiologica (Oxford, England), 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
7 citing papers in PubMed.
- Innovative Dose-Response Assessment of the Metaboreflex With Indirect Control of Intramuscular Metabolic Perturbation in Humans.Acta physiologica (Oxford, England) · 2026Trial
- Delaying task failure in high-intensity exercise: a Pi-afferent-effort framework for targeted sports nutrition.Journal of the International Society of Sports Nutrition · 2026Review
- Impact of total creatine and accessible phosphate pool on endurance exercise: implications for muscle fibers bioenergetic specificity and creatine supplementation.European journal of applied physiology · 2026Article
- Altered Skeletal Muscle Phosphate Metabolism After Muscle Damage Is Associated With Elevated Effort Perception During Exercise in Humans.Scandinavian journal of medicine & science in sports · 2026Article
- Brachial blood flow and pressure responses are unrelated to the greater isometric handgrip tolerance of females compared to males.Physiological reports · 2026Article
- The influence of biological sex on the metabolic basis of skeletal muscle fatigue in vivo.The Journal of physiology · 2025Article
- Skeletal Muscle Fatigue in Rats Is More Consistently Related to Increased Inorganic Phosphate Concentration Than Acidosis.Acta physiologica (Oxford, England) · 2025Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors.
Funding
Abstract
aimDistinguish the relative importance of intramuscular acidosis (hydrogen ion) and inorganic phosphate in skeletal muscle fatigue in vivo in rats.
methodsWe used direct sciatic nerve electrical stimulations to evoke twitches at different frequencies of contraction (0.25-, 0.50-, 0.75-, 1-, 2-, and 4-Hz) in the triceps surae to impose a range of intramuscular metabolic perturbations, quantified by phosphorus nuclear magnetic resonance spectroscopy. Linear mixed-effects models were used to analyze the relationships between peak twitch force and intramuscular hydrogen ion or inorganic phosphate concentration (as Z-scores) during the protocols that decreased peak twitch force (2- and 4-Hz).
resultsAlthough intramuscular hydrogen ion and inorganic phosphate concentrations increased with increasing frequencies of contraction, peak twitch force did not begin to decrease until a "threshold" inorganic phosphate concentration was reached. A given hydrogen ion accumulation was associated with a greater decrease in peak twitch force during 4-Hz compared to 2-Hz (β: -1.19 vs. -0.62, p < 0.001). In contrast, the decrease in peak twitch force for a given inorganic phosphate accumulation was not different between 4- and 2-Hz (β: -0.89 vs. -0.85, p = 0.889).
conclusionsThe inconsistent relationship between the decrease in twitch force and intramuscular hydrogen ion accumulation is not congruent with the primary mechanisms by which acidosis is thought to mediate muscle fatigue. In contrast, the discernible twitch force-inorganic phosphate breakpoint and the consistent relationship between the decrease in twitch force and intramuscular inorganic phosphate accumulation are congruent with the concept of a critical concentration beyond which inorganic phosphate mediates muscle fatigue.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.