Physiological differences in sarcolemmal excitability between human muscles.
Muscle Nerve
; 60(4): 433-436, 2019 10.
Article
in En
| MEDLINE
| ID: mdl-31330047
ABSTRACT
INTRODUCTION:
The sarcolemmal resting membrane potential (RMP) affects muscle excitability, contractility, and force generation. However, there are limited In vivo data on the normal RMP of the human sarcolemma between muscles. We hypothesize that the in vivo RMP may differ between human muscles with different physiological roles.METHODS:
Muscle velocity recovery cycles were recorded from a proximal antigravity muscle, the rectus femoris, and compared with paired recordings from a distal non-antigravity muscle, the tibialis anterior, in 34 normal individuals.RESULTS:
Significant differences in muscle relative refractory period (3.55 millseconds vs 3.87 milliseconds, P = .002), early supernormality (14.22% vs 10.50%, P < .0001), and late supernormality (5.43% vs 3.50%, P < .0001) were observed.DISCUSSION:
The results strongly suggest a less negative RMP in tibialis anterior vs rectus femoris and attest to intermuscle differences in normal excitability and physiology. This novel finding employing an in vivo methodology highlights the need for muscle-specific normative data in future studies.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Refractory Period, Electrophysiological
/
Sarcolemma
/
Quadriceps Muscle
/
Membrane Potentials
Limits:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Muscle Nerve
Year:
2019
Document type:
Article
Affiliation country:
Australia