OBJECTIVETo observe the relation between Pi deficiency syndrome (PDS) and the configuration and functions of extensor digitorum longus (EDL)and soleus (SOL).

METHODSTotally 36 ICR mice were randomly divided into 3 groups according to weight matching principle, the control group, the exhausted group, and the rhubarb group, 12 in each group. Two PDS models were established by either purgation with rhubarb diarrhea (as Group A) or exhausted swimming plus sleep deprivation (as Group B).The cross sectional area (CSA) of type I and II fibers of extensor digitorum longus (EDL) and soleus (SOL), relative proportions of type I and II fibers were measured by m-ATPase histochemical method. The isotonic contraction and the maximum tetanus contraction of EDL and SOL were detected by PowerLab system.

RESULTSCompared with the control group, the body weight, body temperature, and the general health condition of PDS model rats obviously decreased; the spleen index and the thymus index were also lower; the maximal isotonic contraction and the maximum tetanus contraction obviously decreased; the cross section areas of EDL and SOL were reduced with loosely arranged cells. In EDL, the proportion of type I fibers was added and the proportion of type II fibers was lowered. In SOL, there was no change in the proportion of type I and type II fibers.

CONCLUSIONSEDL and SOL were obviously atrophied in the two PDS model mice. The type I fibers of SOL was more significantly atrophied in Group B.