ABSTRACT
Objective To observe the effects of different doses of Sijunzi decoction(SJZD) on soleus(SOL) atrophy in tail-suspended rats.Methods Weightlessness was simulated by tail suspension in female Sprague-Dawley rats.Six rats in each group were assigned to a 5-group design randomly: control(CON);hind limb unloading(HLU) plus intragastric water instillation(HLU-W),as well as plus intragastric high dose(HLU-H),middle dose(HLU-M) and low dose(HLU-L) SJZD instillation respectively.Immunohistochemical method was used to observe the effects of them on expression of myosin heavy chain(MHC) isoforms in soleus muscle.Results Compared with HLU-W,muscle wet weight(MWW) of SOL in high and middle dose group increased by 33.11%and 37.57%respectively,as well as no significant difference with CON;three doses of SJZD groups increased the percentage of type Ⅰ myosin by 34.04%~54.90% and its cross sectional area(CSA) by 8.50%~36.86%,moreover SJZD of middle dose group showed no significant difference with that of CON group.Conclusion Three doses of SJZD groups can significantly prevent soleus atrophy induced by simulated weightlessness,and middle dose is the more effective one than high and low dose.