Abstract: The aim of this study was to investigate MVD, TSP-1, TGF-β1 expression in GH-Secreting Pituitary Adenomas by immunohistochemistry, and to correlate data with clinical characteristics. Method: The protein expression of TSP-1,TGF-β1 in 48 surgical specimens (21invasive cases; 27 noninvasive cases)of pituitary adenomas was measured using immunohistochemical method，and explored the relationship between the expression and invasion of adenomas. MVD were measured by immunohistochemical method with detecting CD34. Results: Compared with the noninvasive group, no differences of expression of CD34 (t=2.257; P=0.083) was observed in the study. The expression of TSP-1 in invasive group was lower. The expression of TGF-β1 was stronger in invasive cases than in noninvasive ones. The expression of TGF-β1 had a positive correlations with MVD; but there was no correlations between the expression of CD34 and the invasion of pituitary adenomas. In addition, MVD count was not associated with the expression of TSP-1. Size, sex or rate of recurrence did not influence MVD and TSP-1 expression. Conclusion: These results suggest that evaluation MVD values do not necessarily represent angiogenesis in pituitary adenomas.However,TGF-β1 maybe involved in upregulating the expression of MVD, and TSP-1 do not influence MVD in pituitary adenomas and maybe regulate angiogenesis by other pathway.

Key words: GH-Secreting Pituitary Adenoma, angiogenesis, microvessel density, thrombospondin-1, TGF-β1