[Effect of shengmai san on diaphragmatic function in rabbits]

After stimulation of the bilateral phrenic nerves of the rabbits, the effect of Shengmai San (SMS) on their normal function and the diaphragmatic fatigue was observed with the measuring of diaphragm evoked potential (DEP), and the analysis of the power spectrum of diaphragmatic electromyogram (EMGdi) at spontaneous breathing. The results were as follows: (1) After the administration of 2 ml/kg of SMS, amplitude of DEP, central frequency, and the high/low frequency ratio were markedly increased. (2) Injecting SMS in 2 ml/kg in 30 minutes before injury could protect significantly against diaphragmatic fatigue following electrical stimulation of the phrenic nerves. (3) Injecting SMS in 2 ml/kg after fatigue could enhance the recovery of the diaphragmatic fatigue.