Evidence map›Paper›PMID 16840514›Full record

Trial reportThe Journal of physiology2006

N-acetylcysteine attenuates the decline in muscle Na+,K+-pump activity and delays fatigue during prolonged exercise in humans.

Michael J McKenna, Ivan Medved, Craig A Goodman, Malcolm J Brown, Andrew R Bjorksten, Kate T Murphy, Aaron C Petersen, Simon Sostaric, Xiaofei Gong

Open access · greenAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in The Journal of physiology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 111 papers, 5 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
111citing papers in PubMed, 5 pooled it
46.6field-weighted citation impact, top 1% of its field
1 · What the graph read from it

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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

111 citing papers in PubMed, 5 syntheses or guidelines pooled it, 259 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Antioxidants for preventing and reducing muscle soreness after exercise.The Cochrane database of systematic reviews · 2017
    Pooled it
  5. Pooled it
  6. Trial
  7. Trial
  8. Trial
  9. Trial
  10. Trial
  11. Trial
  12. Trial
  13. Trial
  14. Trial
  15. N-acetylcysteine in handgrip exercise: plasma thiols and adverse reactions.International journal of sport nutrition and exercise metabolism · 2011
    Trial
  16. Trial
  17. Review
  18. Review
  19. Biopsychological Effects of Ashwagandha (Muscles (Basel, Switzerland) · 2025
    Review
  20. Lactic acidosis: implications for human exercise performance.European journal of applied physiology · 2025
    Review

51 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

9 authors at 3 institutions in 1 country.

Michael J McKennaSchool of Human Movement, Recreation and Performance, Victoria University, PO Box 14428, Melbourne, Victoria, Australia, 8001. michael.mckenna@vu.edu.au
Ivan Medved
Craig A Goodman
Malcolm J Brown
Andrew R Bjorksten
Kate T Murphy
Aaron C Petersen
Simon Sostaric
Xiaofei Gong
Victoria University · AUThe Royal Melbourne Hospital · AUUniversity of Melbourne · AU

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Reactive oxygen species (ROS) have been linked with both depressed Na(+),K(+)-pump activity and skeletal muscle fatigue. This study investigated N-acetylcysteine (NAC) effects on muscle Na(+),K(+)-pump activity and potassium (K(+)) regulation during prolonged, submaximal endurance exercise. Eight well-trained subjects participated in a double-blind, randomised, crossover design, receiving either NAC or saline (CON) intravenous infusion at 125 mg kg(-1) h(-1) for 15 min, then 25 mg kg(-1) h(-1) for 20 min prior to and throughout exercise. Subjects cycled for 45 min at 71% , then continued at 92% until fatigue. Vastus lateralis muscle biopsies were taken before exercise, at 45 min and fatigue and analysed for maximal in vitro Na(+),K(+)-pump activity (K(+)-stimulated 3-O-methyfluorescein phosphatase; 3-O-MFPase). Arterialized venous blood was sampled throughout exercise and analysed for plasma K(+) and other electrolytes. Time to fatigue at 92% was reproducible in preliminary trials (c.v. 5.6 +/- 0.6%) and was prolonged with NAC by 23.8 +/- 8.3% (NAC 6.3 +/- 0.5 versus CON 5.2 +/- 0.6 min, P < 0.05). Maximal 3-O-MFPase activity decreased from rest by 21.6 +/- 2.8% at 45 min and by 23.9 +/- 2.3% at fatigue (P < 0.05). NAC attenuated the percentage decline in maximal 3-O-MFPase activity (%Deltaactivity) at 45 min (P < 0.05) but not at fatigue. When expressed relative to work done, the %Deltaactivity-to-work ratio was attenuated by NAC at 45 min and fatigue (P < 0.005). The rise in plasma [K(+)] during exercise and the Delta[K(+)]-to-work ratio at fatigue were attenuated by NAC (P < 0.05). These results confirm that the antioxidant NAC attenuates muscle fatigue, in part via improved K(+) regulation, and point to a role for ROS in muscle fatigue.

Indexed as

Reactive Oxygen SpeciesAcetylcysteineAcid-Base EquilibriumAdultCross-Over StudiesDouble-Blind MethodExercise TestFree Radical ScavengersHumansMaleMuscle ContractionMuscle FatigueMuscle, SkeletalPhysical EndurancePotassiumSodium-Potassium-Exchanging ATPase3-O-methyl-fluorescein phosphataseAcetylcysteineFree Radical ScavengersPotassiumReactive Oxygen SpeciesSodium-Potassium-Exchanging ATPase

Identifiers

PMID16840514
PMCPMC1995650
OpenAlexW2144193033

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.