Differences in energy metabolism and neuromuscular transmission between 30-Hz and 100-Hz stimulation in rat skeletal muscle

Autor: Takaaki Ikata, Shinjiro Takata
Rok vydání: 2001
Předmět:
Zdroj: Archives of Physical Medicine and Rehabilitation. 82:666-670
ISSN: 0003-9993
DOI: 10.1053/apmr.2001.21942
Popis: To examine differences in energy metabolism and neuromuscular transmission failure in rat hindlimb muscles subjected to electric stimulation at different frequencies.Experimental animal study.Bioenergetic Research Center at Otsuka Pharmaceutical Company, Otsuka, Japan.Thirty-two 25-week-old male Wistar-Kyoto rats.With the rat under general anesthesia, the sciatic nerve was electrically stimulated at 30Hz and 100Hz to induce muscle contraction.Energy level and intracellular pH of muscles by phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS); M-wave amplitude of muscles by electromyography.During the first 4 minutes under stimulation at 30Hz and at 100Hz, energy level and intracellular pH dropped to their lowest values (p.05 or p.01); the values then recovered with time. Recovery rates of energy level and intracellular pH during stimulation at 100Hz were greater than those observed during stimulation at 30Hz. The M-wave amplitude during 100-Hz stimulation was permanently and significantly lower than that measured during 30-Hz stimulation (p.01), and the recovery rate of M-wave amplitude after stimulation at 100Hz was slower than that after stimulation at 30Hz.Neuromuscular transmission failure was greater with 100-Hz stimulation than with 30-Hz stimulation. This finding may account for the rapid recovery of energy level and intracellular pH that occurs with stimulation at 100Hz.
Databáze: OpenAIRE