Abstract: 【OBJECTIVE】To understand the mechanism of Chinese herbal medicine phosphodiesterase inhibitor to increase growth of muscle, theophylline used as reference, the effect of arctiin on phosphodiesterase (PDE) activity and protein synthesis of primary cultured myocytes was investigate;【METHOD】Myoblasts were isolated from 1-3-day-old newborn ICR mice limbs. The medium containing different concentration of arctiin and theophylline was added into cultured myocytes when myotubes were formed. After continuous incubation in incubator for 24 hours, cyclic adenosine 3’, 5’- monophosphate (cAMP) PDE activity, intracellular cAMP and cell total protein were assessed; 【RESULTS】The results were that cAMP PDE activity was most significantly inhibited (P<0.01）, intracellular cAMP level was greatly increased (P<0.05) and amount of cell total protein was most markedly accelerated (P<0.01) by arctiin and theophylline which concentration were respectively 2.5μg/ml and 20μg/ml in medium;【CONCLUSION】These results suggest that Chinese herbal medicine PDE inhibitor may increase skeletal muscle growth by inhibiting the activity of myocytes PDE to regulate the intracellular cAMP level and enhance protein synthesis.

Key words: phosphodiesterase, cyclic adenosine 3’, 5’- monophosphate, arctiin, theophylline, myocytes