OBJECTIVETo observe the effect of Tiancan Zhuangyang Powder (TCZYP) on the steroidogenic acute regulatory protein (stAR protein) expression of Leydig cells in model rats with partial androgen deficiency of aging male (PADAM).

METHODSPADAM rat model was prepared by cyclophosphamide induced reproductive system damage. Rats were randomly divided into four groups, i. e. the normal control group, the model group, the testosterone propionate group, and the TCZYP group. The general condition, body weight, tail suspension experiment and exhaustion swimming test, and the testicular index, etc. were observed to assess the state of rats. The serum total testosterone (TT), and free testosterone (FT) levels were detected by radioimmunoassay before and after treatment. The stAR protein expression level of Leydig cells were determined using immunohistochemical assay. Statistic analyses were performed.

RESULTSBy modeling with cyclophosphamide, serum TT and FT levels decreased (P<0.01), behavior changes were basically similar to PADAM (by tail suspension test), indicating a successful modeling. After treatment serum rTT and FT levels in the testosterone propionate group and the TCZYP group significantly increased when compared with before treatment and with the model group after treatment (P<0.01). There was no statistical difference between the TCZYP group and the testosterone propionate group (P>0.05). The immobility time in the tail suspension test were significantly shortened in the testosterone propionate group and the TCZYP group (P<0.05). The exhausted swimming time was more significantly prolongated than that of the model group (P<0.05). The stAR protein gray value significantly decreased (P<0. 01).

CONCLUSIONTCZYP could prevent serum TT and FT levels from decrease, improve stAR protein activities, and attenuate the depression state and muscular tension in PADAM rats. Its action was equivalent to that of testosterone propionate.