Dynamic changes of expression of Wnt4 in pituitary adenomas tissue in rats

Objective To observe the dynamic changes of Wnt4 expression in pituitary tissue fiom rats with pituitary adenoma models induced by diethylstibestrol (Des),and probe into the possible mechanism of Wnt4 signal transduction pathway in tumorigenesis and development of pituitary adenomas.Methods Sixty Wistar rats were randomly divided into DES-treated group (Des),arachis (o)il-treated control group (AO) and feign-treated control group (FT).Behavior changes and body weight were recorded.Ten rats in DES-treated group and 5 in each control group were sacrificed after 4,8 and 12 weeks,respectively.The weight,histological and morphological changes of the pituitary gland,serum prolactin (PRL) level,and expression of Wnt4 were detected.Results Tumor formation rate was 30％,90％ and 100％,and the Wnt4 positive scores was 5.80 ±3.32,8.40 ±2.22 and 9.70 ± 1.64 at 4th,8th and 12th week in Des group,respectively.The Wnt4 positive scores in control group were 0.80 ± 0.83,1.40 ± 1.14 and 1.20 ± 0.83 at 4th,8th and 12th week,respectively.Wnt4 expression was significantly higher in Des group than in other groups (P ＜ 0.05),and had acending trend along with the treating time of Des.Conclusion Pituitary tumor model induced by Des in Wistar rats was a stable and convenient pituitary tumor model.Wnt4 signal transduction pathway may play an important role in tumorigenesis and development of pituitary adenomas. Key words: Pituitary adenoma ;  Wnt4 ;  Signaling transduction pathway ;  Model, animal