Fatigue from high- and low-frequency muscle stimulation: contractile and biochemical alterations. J Appl Physiol (1985) 1987 May;62(5):2075-82
Date
05/01/1987Pubmed ID
3597276DOI
10.1152/jappl.1987.62.5.2075Scopus ID
2-s2.0-0023192907 (requires institutional sign-in at Scopus site) 51 CitationsAbstract
This study examined the effect of high- (75 Hz, 1 min) and low- (5 Hz, 1.5 min) frequency stimulation on contractile and biochemical properties of the diaphragm. Tension was reduced to 21 +/- 1 and 54 +/- 2% (SE) of the initial value after high- and low-frequency stimulation, respectively. After 0, 0.25, 1, and 2 min of recovery from high-frequency stimulation, 5 Hz elicited more force (expressed as % of initial tension) than 75-Hz stimulation. Time 0 recovery values were 21 +/- 1 and 78 +/- 6% of the initial force for 75- and 5-Hz stimulation, respectively. By 1 min of recovery, force elicited by 5-Hz stimulation had returned to the prefatigue value. In contrast, force production with 75-Hz stimulation did not full recover until 10-15 min. After fatigue produced by low-frequency stimulation, force production with 5-Hz stimulation was reduced to 54 +/- 2% of the initial tension, a value significantly lower than the 71 +/- 2% of initial force elicited by 75-Hz stimulation. Force production with 5-Hz stimulation increased rapidly in the first 15 s of recovery (54 +/- 2% at 0 and 70 +/- 2% at 15 s) and by 5 min was significantly greater than the force elicited by 75-Hz stimulation (100 +/- 3 vs. 93 +/- 1%). As before, force production at 75-Hz stimulation did not fully recover until 10-15 min. Both fatigue protocols produced a significant prolongation in isometric twitch contraction and one-half relaxation times. Creatine phosphate (CP) concentration was reduced and muscle lactate increased by both fatigue protocols.(ABSTRACT TRUNCATED AT 250 WORDS)
Author List
Metzger JM, Fitts RHAuthor
Robert Fitts PhD Professor in the Biological Sciences department at Marquette UniversityMESH terms used to index this publication - Major topics in bold
Adenosine TriphosphateAnimals
Calcium
Diaphragm
Electric Stimulation
Female
Hydrogen-Ion Concentration
In Vitro Techniques
Isometric Contraction
Lactates
Lactic Acid
Muscle Contraction
Phosphocreatine
Rats
Rats, Inbred Strains