RESUMEN
<p><b>AIM</b>To detect effect of the different frequency of chronic electrical stimulation (CES) on myofibrillar isoform, myosin heavy chain (MHC) and metabolic enzyme activities.</p><p><b>METHODS</b>The histochemical method and SDS-polyacrylamide gel electrophoresis were respectively employed.</p><p><b>RESULTS</b>(1)There were a significant increase in I myo-fibrillar isoform and I MHC isoform and decrease in II B myofibrillar isoform and II B MHC isoforms in the chronic low frequency electrical stimulation (CLFES) 10 Hz and 20 Hz groups, but opposite results were found in the chronic high frequency electrical stimulation (CHFES) 50 Hz and 100 Hz groups. (2) There were a significant increase in the aerobic-oxidative enzyme activities and capacity, and a concomitant significant drop in glycolysis enzyme activities in CLFES groups, but opposite results were found in CHFES 50 Hz and 100 Hz groups.</p><p><b>CONCLUSION</b>It was suggested that there was a significant dependent relation between chronic electrical stimulation frequency and myofibrilla isoforms, myosin heavy chain (MHC) and metabolic enzyme activities.</p>