Induction of myogenin messenger ribonucleic acid in rat skeletal muscle after 1 hour of passive repetitive stretching.

Abstract

To investigate the effect of repetitive passive stretch of living rat muscle on myogenin messenger ribonucleic acid (mRNA) expression. Case-controlled study. University laboratory. Seventeen female 8-week-old Wistar rats. Repetitive stretch (15 times/min) was performed manually on gastrocnemius muscle of anesthetized rats for 15, 30, and 60 minutes. Total RNA was extracted, after the animals were killed, from the gastrocnemius muscle, and Northern blotting was performed using oligonucleotide complementary to myogenin. Repetitive stretch to gastrocnemius muscles of anesthetized rats for 1 hour induced a 21.5% increase in the expression of myogenin mRNA. Repetitive passive stretch of the rat skeletal muscle for 60 minutes induced the expression of myogenic transcription factor myogenin mRNA. These findings suggest the clinical utility of passive repetitive stretch to maintain muscle strength in patients who are unconscious or paralyzed.